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Sample records for african migratory locust

  1. Thiol-activated serine proteinases from nymphal hemolymph of the African migratory locust, Locusta migratoria migratorioides.

    PubMed

    Hanzon, Jacob; Smirnoff, Patricia; Applebaum, Shalom W; Mattoo, Autar K; Birk, Yehudith

    2003-02-01

    Two unique serine proteinase isoenzymes (LmHP-1 and LmHP-2) were isolated from the hemolymph of African migratory locust (Locusta migratoria migratorioides) nymphs. Both have a molecular mass of about 23 kDa and are activated by thiol-reducing agents. PMSF abolishes enzymes activity only after thiol activation, while the cysteine proteinase inhibitors E-64, iodoacetamide, and heavy metals fail to inhibit the thiol-activated enzymes. The N-terminal sequence was determined for the more-abundant LmHP-2 isoenzyme. It exhibits partial homology to that of other insect serine proteinases and similar substrate specificity and inhibition by the synthetic and protein trypsin inhibitors pABA, TLCK, BBI, and STI. The locust trypsins LmHP-1 and LmHP-2 constitute a new category of serine proteases wherein the active site of the enzyme is exposed by thiol activation without cleavage of peptide bonds. PMID:12559979

  2. Two dopamine receptors play different roles in phase change of the migratory locust

    PubMed Central

    Guo, Xiaojiao; Ma, Zongyuan; Kang, Le

    2015-01-01

    The migratory locust, Locusta migratoria, shows remarkable phenotypic plasticity at behavioral, physiological, and morphological levels in response to fluctuation in population density. Our previous studies demonstrated that dopamine (DA) and the genes in the dopamine metabolic pathway mediate phase change in Locusta. However, the functions of different dopamine receptors in modulating locust phase change have not been fully explored. In the present study, DA concentration in the brain increased during crowding and decreased during isolation. The expression level of dopamine receptor 1 (Dop1) increased from 1 to 4 h of crowding, but remained unchanged during isolation. Injection of Dop1 agonist SKF38393 into the brains of solitary locusts promoted gregarization, induced conspecific attraction-response and increased locomotion. RNAi knockdown of Dop1 and injection of antagonist SCH23390 in gregarious locusts induced solitary behavior, promoted the shift to repulsion-response and reduced locomotion. By contrast, the expression level of dopamine receptor 2 (Dop2) gradually increased during isolation, but remained stable during crowding. During the isolation of gregarious locusts, injection of Dop2 antagonist S(–)-sulpiride or RNAi knockdown of Dop2 inhibited solitarization, maintained conspecific attraction-response and increased locomotion; by comparison, the isolated controls displayed conspecific repulsion-response and weaker motility. Activation of Dop2 in solitary locusts through injection of agonist, R(-)-TNPA, did not affect their behavioral state. Thus, DA-Dop1 signaling in the brain of Locusta induced the gregariousness, whereas DA-Dop2 signaling mediated the solitariness. Our study demonstrated that Dop1 and Dop2 modulated locust phase change in two different directions. Further investigation of Locusta Dop1 and Dop2 functions in modulating phase change will improve our understanding of the molecular mechanism underlying phenotypic plasticity in locusts

  3. Mitochondrial genomes reveal the global phylogeography and dispersal routes of the migratory locust.

    PubMed

    Ma, Chuan; Yang, Pengcheng; Jiang, Feng; Chapuis, Marie-Pierre; Shali, Yasen; Sword, Gregory A; Kang, Le

    2012-09-01

    The migratory locust, Locusta migratoria, is the most widely distributed grasshopper species in the world. However, its global genetic structure and phylogeographic relationships have not been investigated. In this study, we explored the worldwide genetic structure and phylogeography of the locust populations based on the sequence information of 65 complete mitochondrial genomes and three mitochondrial genes of 263 individuals from 53 sampling sites. Although this locust can migrate over long distances, our results revealed high genetic differentiation among the geographic populations. The populations can be divided into two different lineages: the Northern lineage, which includes individuals from the temperate regions of the Eurasian continent, and the Southern lineage, which includes individuals from Africa, southern Europe, the Arabian region, India, southern China, South-east Asia and Australia. An analysis of population genetic diversity indicated that the locust species originated from Africa. Ancestral populations likely separated into Northern and Southern lineages 895 000 years ago by vicariance events associated with Pleistocene glaciations. These two lineages evolved in allopatry and occupied their current distributions in the world via distinct southern and northern dispersal routes. Genetic differences, caused by the long-term independent diversification of the two lineages, along with other factors, such as geographic barriers and temperature limitations, may play important roles in maintaining the present phylogeographic patterns. Our phylogeographic evidence challenged the long-held view of multiple subspecies in the locust species and tentatively divided it into two subspecies, L. m. migratoria and L. m. migratorioides. PMID:22738353

  4. Using field data to test locust migratory band collective movement models

    PubMed Central

    Buhl, J.; Sword, Gregory A.; Simpson, Stephen J.

    2012-01-01

    Wingless locust nymphs can form massive migratory groups known as bands, whose coordinated movement results from local interactions. We analysed the spatial distribution of locusts within naturally occurring bands and compared them with computer simulations to infer which interaction rules are used by individuals. We found that the empirical radial distribution of neighbours around a focal individual was isotropic, indicating a tendency for locusts to interact with neighbours all around them, rather than a bias towards pursuing individuals ahead or escaping from the ones following behind. By using maps of neighbour densities and pair correlation functions, we found evidence for a short-range repulsion force, balanced by a clustering force, presumably alignment and/or attraction, at a distance of around 3 cm. These results were similar to those observed when using a ‘zonal’ self-propelled particles model where repulsion/alignment/attraction forces are delimited by concentric circular zones of set radii. However, the profiles obtained either by using different combinations of forces, limiting the number of neighbours involved in interactions, or by varying the range of some zones, all appeared to produce similar results, thereby limiting the ability to more precisely determine the rules underlying locust interactions. PMID:24312729

  5. Behavioral thermoregulation in the migratory locust: a therapy to overcome fungal infection.

    PubMed

    Ouedraogo, R M; Goettel, M S; Brodeur, J

    2004-01-01

    We examined under laboratory conditions the thermopreference of the migratory locust, Locusta migratoria migratorioides, following infection by the entomopathogenic fungus Metarhizium anisopliae var. acridum and its influence on mycosis. Infected locusts raised their body temperature more frequently than healthy conspecifics through selection of high temperatures in a heat gradient. Thermoregulation did not, however, alter the frequency of feeding events nor the amount of food eaten by infected L. migratoria. A thermoregulation regime of a minimum of 4 h/day substantially increased survival of inoculated insects (by 85%). However, the therapeutic effect decreased when thermoregulation was delayed following inoculation of the pathogen. Thermoregulation reduced locust mortality but did not completely eliminate the fungus from infected hosts; the fungus grew and killed the insects when thermoregulation was interrupted. We suggest that periodic, short bouts of thermoregulation, when performed from the onset of infection and for an extended period of time, are sufficient to provide a therapeutic effect to infected hosts. Such thermoregulatory capacity of locusts may limit the potential of fungal pathogens as biological control agents under certain ecological conditions. PMID:14614620

  6. Molecular characterization and expression profiles of neuropeptide precursors in the migratory locust.

    PubMed

    Hou, Li; Jiang, Feng; Yang, Pengcheng; Wang, Xianhui; Kang, Le

    2015-08-01

    Neuropeptides serve as the most important regulatory signals in insects. Many neuropeptides and their precursors have been identified in terms of the contig sequences of whole genome information of the migratory locust (Locusta migratoria), which exhibits a typical phenotypic plasticity in morphology, behavior and physiology. However, functions of these locust neuropeptides are largely unknown. In this study, we first revised the 23 reported neuropeptide precursor genes and identified almost all the neuropeptide precursors and corresponding products in L. migratoria. We further revealed the significant expansion profiles (such as AKH) and alternative splicing of neuropeptide genes (Lom-ITP, Lom-OK and Lom-NPF1). Transcriptomic analysis indicated that several neuropeptides, such as Lom-ACP and Lom-OK, displayed development-specific expression patterns. qRT-PCR data confirmed that most neuropeptide precursors were strongly expressed in the central nervous system. Fifteen neuropeptide genes displayed different expression levels between solitarious and gregarious locusts. These findings provide valuable clues to understand neuropeptide evolution and their functional roles in basic biology and phase transition in locusts. PMID:26036749

  7. Evidence for Widespread Genomic Methylation in the Migratory Locust, Locusta migratoria (Orthoptera: Acrididae)

    PubMed Central

    Robinson, Katie L.; Tohidi-Esfahani, Donya; Lo, Nathan; Simpson, Stephen J.; Sword, Gregory A.

    2011-01-01

    The importance of DNA methylation in mammalian and plant systems is well established. In recent years there has been renewed interest in DNA methylation in insects. Accumulating evidence, both from mammals and insects, points towards an emerging role for DNA methylation in the regulation of phenotypic plasticity. The migratory locust (Locusta migratoria) is a model organism for the study of phenotypic plasticity. Despite this, there is little information available about the degree to which the genome is methylated in this species and genes encoding methylation machinery have not been previously identified. We therefore undertook an initial investigation to establish the presence of a functional DNA methylation system in L. migratoria. We found that the migratory locust possesses genes that putatively encode methylation machinery (DNA methyltransferases and a methyl-binding domain protein) and exhibits genomic methylation, some of which appears to be localised to repetitive regions of the genome. We have also identified a distinct group of genes within the L. migratoria genome that appear to have been historically methylated and show some possible functional differentiation. These results will facilitate more detailed research into the functional significance of DNA methylation in locusts. PMID:22163001

  8. Identification and functional analysis of olfactory receptor family reveal unusual characteristics of the olfactory system in the migratory locust.

    PubMed

    Wang, Zhifeng; Yang, Pengcheng; Chen, Dafeng; Jiang, Feng; Li, Yan; Wang, Xianhui; Kang, Le

    2015-11-01

    Locusts represent the excellent model of insect olfaction because the animals are equipped with an unusual olfactory system and display remarkable density-dependent olfactory plasticity. However, information regarding receptor molecules involved in the olfactory perception of locusts is very limited. On the basis of genome sequence and antennal transcriptome of the migratory locust, we conduct the identification and functional analysis of two olfactory receptor families: odorant receptors (ORs) and ionotropic receptors (IRs). In the migratory locust, there is an expansion of OR family (142 ORs) while distinctly lower number of IR genes (32 IRs) compared to the repertoires of other insects. The number of the locust OR genes is much less than that of glomeruli in antennal lobe, challenging the general principle of the "one glomerulus-one receptor" observed in other insects. Most OR genes are found in tandem arrays, forming two large lineage-specific subfamilies in the phylogenetic tree. The "divergent IR" subfamily displays a significant contraction, and most of the IRs belong to the "antennal IR" subfamily in the locust. Most ORs/IRs have olfactory-specific expression while some broadly- or internal-expressed members are also found. Differing from holometabolous insects, the migratory locust contains very similar expression profiles of ORs/IRs between nymph and adult stages. RNA interference and behavioral assays indicate that an OR-based signaling pathway, not IR-based, mediates the attraction of locusts to aggregation pheromones. These discoveries provide insights into the unusual olfactory system of locusts and enhance our understanding of the evolution of insect olfaction. PMID:26265180

  9. Large-Scale Transcriptome Analysis of Retroelements in the Migratory Locust, Locusta migratoria

    PubMed Central

    Guo, Wei; Wang, Xianhui; Kang, Le

    2012-01-01

    Background Retroelements can successfully colonize eukaryotic genome through RNA-mediated transposition, and are considered to be some of the major mediators of genome size. The migratory locust Locusta migratoria is an insect with a large genome size, and its genome is probably subject to the proliferation of retroelements. An analysis of deep-sequencing transcriptome data will elucidate the structure, diversity and expression characteristics of retroelements. Results We performed a de novo assembly from deep sequencing RNA-seq data and identified 105 retroelements in the locust transcriptome. Phylogenetic analysis of reverse transcriptase sequences revealed 1 copia, 1 BEL, 8 gypsy and 23 non-long terminal repeat (LTR) retroelements in the locust transcriptome. A novel approach was developed to identify full-length LTR retroelements. A total of 5 full-length LTR retroelements and 2 full-length non-LTR retroelements that contained complete structures for retrotransposition were identified. Structural analysis indicated that all these retroelements may have been activated or deprived of retrotransposition activities very recently. Expression profiling analysis revealed that the retroelements exhibited a unique expression pattern at the egg stage and showed differential expression profiles between the solitarious and gregarious phases at the fifth instar and adult stage. Conclusion We hereby present the first de novo transcriptome analysis of retroelements in a species whose genome is not available. This work contributes to a comprehensive understanding of the landscape of retroelements in the locust transcriptome. More importantly, the results reveal that non-LTR retroelements are abundant and diverse in the locust transcriptome. PMID:22792363

  10. Lack of essential enzymes for the biosynthesis of C19 and C18 steroids in gonads of the migratory locust, Locusta migratoria.

    PubMed

    Swevers, L; Lambert, J G; Novak, F; Paesen, G; De Loof, A

    1991-11-01

    Ovaries and testes of the African migratory locust, Locusta migratoria migratorioides, were incubated in vitro with six tritiated steroid precursors. Three developmental stages were investigated--1 day, 14 days, and 6 weeks after adult moulting. 20 alpha-Hydroxysteroid dehydrogenase (HSD), 20 beta-HSD, 17 beta-HSD, 3 beta-HSD/isomerase, C17-C20 lyase, glucuronyl-transferase, sulfotransferase, and acyltransferase were identified in both sexes. A synthesis of androgens or estrogens comparable to the vertebrate type, however, was not apparent in the locust gonads. 20 alpha-HSD, 20 beta-HSD, and 17 beta-HSD activities were high, while more important steps in steroid synthesis such as 3 beta-HSD and C17-C20 lyase were far less intense. Ovarian 17 alpha-hydroxylase activity was slight. Aromatase activity was not demonstrated. Water-soluble conjugate formation was high in the incubations of "14th-day" and "6th-week" gonads but was absent in "1st-day" ovaries and testes. Active ester formation of pregnenolone was demonstrated in "6th-week" testes. The other steroid conversions were similar in all developmental stages investigated. Major differences between testes and ovaries were not observed. The gonads of the migratory locust are concluded not to produce androgens or estrogens. PMID:1783269

  11. Alternative migratory locust phenotypes are associated with differences in the expression of genes encoding the methylation machinery.

    PubMed

    Robinson, K L; Tohidi-Esfahani, D; Ponton, F; Simpson, S J; Sword, G A; Lo, N

    2016-04-01

    Despite the importance of locust density-dependent polyphenism as a model system for understanding phenotypic plasticity, there is still much to be learnt about its underlying molecular control. Here we describe the first investigation into the expression of genes encoding the DNA methylation machinery in the migratory locust (Locusta migratoria). We show that the alternative solitarious and gregarious phenotypic states induced by different locust rearing densities are associated with significant differences in the expression of the target genes DNA methyltransferase 1, DNA methyltransferase 2 and methyl-CpG-binding domain protein 2/3. This variation was most pronounced in the embryos of solitarious vs. gregarious mothers. We mapped the embryonic methylation profiles of several intragenic regions and a Long Interspersed Nuclear Element (LINE), each of which is known to be differentially expressed between alternative locust phenotypes or has been directly implicated in phase change. LmI and three genes, adenyl cyclase-associated binding protein 2, choline kinase alpha-like and henna, were methylated. Our results set the stage for future studies investigating the specific role of DNA methylation in the maternal transfer of migratory locust phase polyphenism. PMID:26612460

  12. The cytogenetic effects of the aqueous extracts of migratory locust (Locusta migratoria L.) in vitro.

    PubMed

    Turkez, Hasan; Incekara, Umit; Güner, Adem; Aydın, Elanur; Dirican, Ebubekir; Togar, Başak

    2014-04-01

    One of the useful and most commonly cultivated commercially species, migratory locust (Locusta migratoria; Orthoptera), was investigated in light of genotoxic damage potentials. For this aim, we evaluated the genotoxic potentials of water soluble extracts of L. migratoria on cultured human blood cells. The micronucleus, sister chromatid exchange and structural chromosome aberration assays were applied to assess DNA and chromosomal damage produced by aqueous extracts in vitro. The extracts were added to the cultures at different concentrations ranging from 0 to 1000 mg/L. Our results indicated that these extracts did not exhibit genotoxicity at tested concentrations. We conclude that this in vitro approach for biomonitoring genotoxicity assessment is useful for comparing the potential health risks of edible insects. PMID:22872633

  13. Recognition and characterization of migratory movements of Australian plague locusts, Chortoicetes terminifera, with an insect monitoring radar

    NASA Astrophysics Data System (ADS)

    Drake, V. Alistair; Wang, Haikou

    2013-01-01

    Two special purpose insect-detecting radar units have operated in inland eastern Australia, in the region where nocturnal migratory movements of Australian plague locusts Chortoicetes terminifera occur, for over 10 years. The fully automatic radars detect individual insects as they fly directly overhead and "interrogate" them to obtain information about their characters (size, shape, and wing beating) and trajectory (speed, direction, and orientation). The character data allow locusts to be distinguished from most other migrant species. A locust index, calculated from the total count of locust-like targets for a night, provides a simple indication of migration intensity. For nights of heavy migration, the variation of numbers, directions, and speeds with both height and time can be examined. Emigration and immigration events can be distinguished, as can "transmigration," the passage overhead of populations originating elsewhere. Movement distances can be inferred, and broad source and (more tentatively) destination regions are identified. Movements were typically over distances of up to 400 km. Interpretation of radar observations requires judgment, and the present two units provide only partial coverage of the locust infestation area, but their capacity to detect major population movements promptly, and to provide information between necessarily infrequent surveys, has proved valuable.

  14. Characterization and Functional Analysis of Four Glutathione S-Transferases from the Migratory Locust, Locusta migratoria

    PubMed Central

    Qin, Guohua; Jia, Miao; Liu, Ting; Zhang, Xueyao; Guo, Yaping; Zhu, Kun Yan; Ma, Enbo; Zhang, Jianzhen

    2013-01-01

    Glutathione S-transferases (GSTs) play an important role in detoxification of xenobiotics in both prokaryotic and eukaryotic cells. In this study, four GSTs (LmGSTd1, LmGSTs5, LmGSTt1, and LmGSTu1) representing different classes were identified from the migratory locust, Locusta migratoria. These four proteins were heterologously expressed in Escherichia coli as soluble fusion proteins, purified by Ni2+-nitrilotriacetic acid agarose column and biochemically characterized. LmGSTd1, LmGSTs5, and LmGSTu1 showed high activities with 1-chloro-2, 4-dinitrobenzene (CDNB), detectable activity with p-nitro-benzyl chloride (p-NBC) and 1, 2-dichloro-4-nitrobenzene (DCNB), whereas LmGSTt1 showed high activity with p-NBC and detectable activity with CDNB. The optimal pH of the locust GSTs ranged between 7.0 to 9.0. Ethacrynic acid and reactive blue effectively inhibited all four GSTs. LmGSTs5 was most sensitive to heavy metals (Cu2+ and Cd2+). The maximum expression of the four GSTs was observed in Malpighian tubules and fat bodies as evaluated by western blot. The nymph mortalities after carbaryl treatment increased by 28 and 12% after LmGSTs5 and LmGSTu1 were silenced, respectively. The nymph mortalities after malathion and chlorpyrifos treatments increased by 26 and 18% after LmGSTs5 and LmGSTu1 were silenced, respectively. These results suggest that sigma GSTs in L. migratoria play a significant role in carbaryl detoxification, whereas some of other GSTs may also involve in the detoxification of carbaryl and chlorpyrifos. PMID:23505503

  15. Sulfakinin is an important regulator of digestive processes in the migratory locust, Locusta migratoria.

    PubMed

    Zels, Sven; Dillen, Senne; Crabbé, Katleen; Spit, Jornt; Nachman, Ronald J; Vanden Broeck, Jozef

    2015-06-01

    Sulfakinin (SK) is a sulfated insect neuropeptide that is best known for its function as a satiety factor. It displays structural and functional similarities with the vertebrate peptides gastrin and cholecystokinin. Peptidomic studies in multiple insects, crustaceans and arachnids have revealed the widespread occurrence of SK in the arthropod phylum. Multiple studies in hemi- and holometabolous insects revealed the pleiotropic nature of this neuropeptide: in addition to its activity as a satiety factor, SK was also reported to affect muscle contraction, digestive enzyme release, odor preference, aggression and metabolism. However, the main site of action seems to be the digestive system of insects. In this study, we have investigated whether SK can intervene in the control of nutrient uptake and digestion in the migratory locust (Locusta migratoria). We provide evidence that sulfakinin reduces food uptake in this species. Furthermore, we discovered that SK has very pronounced effects on the main digestive enzyme secreting parts of the locust gut. It effectively reduced digestive enzyme secretion from both the midgut and gastric caeca. SK injection also elicited a reduction in absorbance and proteolytic activity of the gastric caeca contents. The characteristic sulfation of the tyrosine residue is crucial for the observed effects on digestive enzyme secretion. In an attempt to provide potential leads for the development of peptidomimetic compounds based on SK, we also tested two mimetic analogs of the natural peptide ligand in the digestive enzyme secretion assay. These analogs were able to mimic the effect of the natural SK, but their effects were milder. The results of this study provide new insights into the action of SK on the digestive system in (hemimetabolous) insects. PMID:25846060

  16. Molecular and functional analysis of UDP-N-acetylglucosamine Pyrophosphorylases from the Migratory Locust, Locusta migratoria.

    PubMed

    Liu, Xiaojian; Li, Feng; Li, Daqi; Ma, Enbo; Zhang, Wenqing; Zhu, Kun Yan; Zhang, Jianzhen

    2013-01-01

    UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA's derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species. PMID:23977188

  17. Molecular and Functional Analysis of UDP-N-Acetylglucosamine Pyrophosphorylases from the Migratory Locust, Locusta migratoria

    PubMed Central

    Li, Daqi; Ma, Enbo; Zhang, Wenqing; Zhu, Kun Yan; Zhang, Jianzhen

    2013-01-01

    UDP-N-acetylglucosamine pyrophosphorylases (UAP) function in the formation of extracellular matrix by producing N-acetylglucosamine (GlcNAc) residues needed for chitin biosynthesis and protein glycosylation. Herein, we report two UAP cDNA’s derived from two different genes (LmUAP1 and LmUAP2) in the migratory locust Locusta migratoria. Both the cDNA and their deduced amino acid sequences showed about 70% identities between the two genes. Phylogenetic analysis suggests that LmUAP1 and LmUAP2 derive from a relatively recent gene duplication event. Both LmUAP1 and LmUAP2 were widely expressed in all the major tissues besides chitin-containing tissues. However, the two genes exhibited different developmental expression patterns. High expression of LmUAP1 was detected during early embryogenesis, then decreased greatly, and slowly increased before egg hatch. During nymphal development, the highest expression of LmUAP1 appeared just after molting but declined in each inter-molting period and then increased before molting to the next stage, whereas LmUAP2 was more consistently expressed throughout all these stages. When the early second- and fifth-instar nymphs (1-day-old) were injected with LmUAP1 double-stranded RNA (dsRNA), 100% mortality was observed 2 days after the injection. When the middle second- and fifth-instar nymphs (3- to 4-day-old) were injected with LmUAP1 dsRNA, 100% mortality was observed during their next molting process. In contrast, when the insects at the same stages were injected with LmUAP2 dsRNA, these insects were able to develop normally and molt to the next stage successfully. It is presumed that the lethality caused by RNAi of LmUAP1 is due to reduced chitin biosynthesis of the integument and midgut, whereas LmUAP2 is not essential for locust development at least in nymph stage. This study is expected to help better understand different functions of UAP1 and UAP2 in the locust and other insect species. PMID:23977188

  18. Endocrine control of TAG lipase in the fat body of the migratory locust, Locusta migratoria.

    PubMed

    Auerswald, Lutz; Gäde, Gerd

    2006-10-01

    Aspects of the role and activation of the enzyme triacylglycerol lipase (TAG lipase) in the fat body of the migratory locust Locusta migratoria were investigated. TAG lipase is under the hormonal control of the three endogenous adipokinetic peptides of the migratory locust, Locmi-AKH-I, Locmi-AKH-II and Locmi-AKH-III. Injection of low doses (5-10 pmol) of each peptide causes an increase in lipase activity. The activation of lipase is time dependent: an elevated activity was recorded 15 min after injection of 10 pmol Locmi-AKH-I and maximum activation was reached after 45-60 min. The activation of TAG lipase is also dose-dependent. Doses of 2 pmol of each Locmi-AKH had no effect, whereas 5 pmol caused a significant activation. Maximum activation is reached with a dose of 10 pmol. Analogues of the second messengers cAMP (cpt-cAMP) and IP(3) (F-IP(3)) both activate the enzyme glycogen phosphorylase whereas only cpt-cAMP, but not F-IP(3), activates TAG lipase; cpt-cAMP elevates the lipid levels in the haemolymph. Activation of lipase is specific to the three endogenous AKH peptides: 5 pmol of the endogenous peptide Locmi-HrTH and 10 pmol of corazonin failed to activate lipase. High doses of octopamine did not activate lipase nor did they elevate the lipid concentration in the haemolymph. TAG lipase is stimulated by flight activity but activation is slower than that of glycogen phosphorylase: after 30 min of flight or after 5 min of flight plus 1h of subsequent rest, activity of TAG lipase is increased, but not immediately after 5 min of flight. In contrast, glycogen phosphorylase is activated significantly after 5 min of flight. These activation patterns of the two enzymes mirror-image the concentration of their substrates in the haemolymph: there is a significant decrease in the concentration of carbohydrates after 5 min of flight, whereas no change of the concentration of lipids can be measured after such short time of flight activity; however, a subsequent rest

  19. Haemocyanin is essential for embryonic development and survival in the migratory locust.

    PubMed

    Chen, B; Ma, R; Ma, G; Guo, X; Tong, X; Tang, G; Kang, L

    2015-10-01

    Haemocyanins are commonly known as copper-containing oxygen carriers within the haemolymph of arthropods, and have been found in many orders of insects. However, it remains unresolved why haemocyanins persist in insects that possess elaborate tracheal systems for oxygen diffusion to cells. Here we identified haemocyanins in the migratory locust Locusta migratoria that consists of two distinct subunits, Hc1 and Hc2. Genomic sequence analysis indicated that Hc1 and Hc2 have four and three gene copies, respectively, which may have evolved via gene duplication followed by divergent evolution of introns. The two subunits exhibit abundant and embryonic-specific expression at the mRNA and protein level; their expression peaks in the mid-term embryo and is not detectable in the late nymphal and adult stages. A larger proportion of the haemocyanins is present in the yolk compared with that in the embryo. Immunostaining shows that haemocyanins in the embryo are mainly expressed in the epidermis. Knockdown of Hc1 and Hc2 results in significant embryonic developmental delay and abnormality as well as reduced egg hatchability, ie the proportion of hatched eggs. These results reveal a previously unappreciated and fundamental role for haemocyanins in embryonic development and survival in insects, probably involving the exchange of molecules (eg O2 ) between the embryo and its environment. PMID:26010377

  20. Krüppel-homolog 1 mediates juvenile hormone action to promote vitellogenesis and oocyte maturation in the migratory locust.

    PubMed

    Song, Jiasheng; Wu, Zhongxia; Wang, Zhiming; Deng, Shun; Zhou, Shutang

    2014-09-01

    Juvenile hormone (JH) prevents insect larval metamorphosis and stimulates processes for adult reproduction. Krüppel-homolog 1 (Kr-h1), a zinc finger transcription factor, is shown to mediate the anti-metamorphic effect of JH in both holometabolous and hemimetabolous insects. However, the role of Kr-h1 in JH-mediated reproduction has not been determined. Using the migratory locust, Locusta migratoria, we showed here that Kr-h1 was expressed in response to JH in female adults, and Kr-h1 transcription was directly regulated by the JH-receptor complex comprised of Methoprene-tolerant (Met) and steroid receptor co-activator. We demonstrated that Kr-h1 RNAi phenocopied Met RNAi and JH-deprived condition during post-eclosion development and vitellogenesis of female locusts. Knockdown of Kr-h1 resulted in substantial reduction of Vg expression in the fat body and lipid accumulation in the primary oocytes, accompanied by blocked follicular epithelium development, oocyte maturation and ovarian growth. Our data therefore reveal a crucial role of Kr-h1 in insect vitellogenesis and egg production. This study suggests that JH-Met-Kr-h1 signaling pathway is also functional in insect reproduction. PMID:25017142

  1. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors.

    PubMed

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

    2016-01-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects. PMID:27581362

  2. Transcriptional Analysis of The Adaptive Digestive System of The Migratory Locust in Response to Plant Defensive Protease Inhibitors

    PubMed Central

    Spit, Jornt; Holtof, Michiel; Badisco, Liesbet; Vergauwen, Lucia; Vogel, Elise; Knapen, Dries; Vanden Broeck, Jozef

    2016-01-01

    Herbivorous insects evolved adaptive mechanisms to compensate for the presence of plant defensive protease inhibitors (PI) in their food. The underlying regulatory mechanisms of these compensatory responses remain largely elusive. In the current study, we investigated the initiation of this adaptive response in the migratory locust, Locusta migratoria, via microarray analysis of gut tissues. Four hours after dietary uptake of PIs, 114 and 150 transcripts were respectively found up- or downregulated. The results suggest a quick trade-off between compensating for potential loss of digestive activity on the one hand, and stress tolerance, defense, and structural integrity of the gut on the other hand. We additionally addressed the role of a group of related upregulated hexamerin-like proteins in the PI-induced response. Simultaneous knockdown of corresponding transcripts by means of RNA interference resulted in a reduced capacity of the locust nymphs to cope with the effects of PI. Moreover, since insect hexamerins have been shown to bind Juvenile Hormone (JH), we also investigated the effect of JH on the proteolytic digestion in L. migratoria. Our results indicate that JH has a stimulatory effect on the expression of three homologous chymotrypsin genes, while knocking down the JH receptor (methoprene tolerant) led to opposite effects. PMID:27581362

  3. Fate and effects of the trehalase inhibitor trehazolin in the migratory locust (Locusta migratoria).

    PubMed

    Liebl, Martina; Nelius, Victoria; Kamp, Günter; Ando, Osamu; Wegener, Gerhard

    2010-06-01

    Trehalose is the main haemolymph sugar in many insect species. To be utilized trehalose must be hydrolysed into its glucose units by trehalase (EC 3.2.1.28). Inhibitors of trehalase have attracted interest as possible pesticides and tools for studying the regulation of trehalose metabolism in insects. To make full use of these inhibitors requires knowledge of their fate and effects in vivo. To this end we have measured trehazolin in locusts using a method based on the specific inhibition of a trehalase preparation. After injection of 20 microg, trehazolin decreased in haemolymph with a half-life of 2.6 days and after 10 days almost 95% had disappeared. Trehazolin did not reach the intracellular water space of locust tissues, but appeared with full inhibitory potency in locust faeces, suggesting that it was not metabolized, but quantitatively eliminated via the gut. Haemolymph trehalose increased transiently upon trehazolin injection, it was maximal after 3 days, then decreased and reached control level after 10 days. Inhibition of flight muscle trehalase by trehazolin was prolonged and still conspicuous 21 days post injection, suggesting that trehazolin inhibits trehalase activity irreversibly in vivo and that recovery requires de novo enzyme synthesis. PMID:19958774

  4. Inulinase production by Geotrichum candidum OC-7 using migratory locusts as a new substrate and optimization process with Taguchi DOE.

    PubMed

    Canli, Ozden; Tasar, Gani Erhan; Taskin, Mesut

    2013-09-01

    Utilization of migratory locusts (Locusta migratoria) as a main substrate due to its high protein content for inulinase (2,1-β-d-fructan fructanohydrolase) production by Geotrichum candidum OC-7 was investigated in this study. To optimize fermentation conditions, four influential factors (locust powder (LP) concentration, sucrose concentration, pH and fermentation time) at three levels were investigated using Taguchi orthogonal array (OA) design of experiment (DOE). Inulinase yield obtained from the designed experiments with regard to Taguchi L9 OA was processed with Minitab 15 software at 'larger is better' as quality character. The results showed that optimal fermentation conditions determined as LP 30 g/l, sucrose 20 g/l, pH 6.0 and time 48 h. Maximum inulinase activity was recorded as 30.12 U/ml, which was closer to the predicted value (30.56 U/ml). To verify the results, analysis of variance test was employed. LP had the greatest contribution (71.96%) among the other factors. Sucrose had lower contribution (13.96%) than LP. This result demonstrated that LP had a strong effect on inulinase activity and can be used for enzyme production. Taguchi DOE application enhanced enzyme activity to about 3.05-fold versus unoptimized condition and 2.34-fold versus control medium. Consequently, higher inulinase production can be achieved by the utilization of an edible insect material as an alternative substrate and Taguchi DOE presents suitable optimization method for biotechnological process. PMID:22495518

  5. Molecular and Functional Characterization of cDNAs Putatively Encoding Carboxylesterases from the Migratory Locust, Locusta migratoria

    PubMed Central

    Zhang, Jianqin; Li, Daqi; Ge, Pingting; Guo, Yaping; Zhu, Kun Yan; Ma, Enbo; Zhang, Jianzhen

    2014-01-01

    Carboxylesterases (CarEs) belong to a superfamily of metabolic enzymes encoded by a number of genes and are widely distributed in microbes, plants and animals including insects. These enzymes play important roles in detoxification of insecticides and other xenobiotics, degradation of pheromones, regulation of neurodevelopment, and control of animal development. In this study, we characterized a total of 39 full-length cDNAs putatively encoding different CarEs from the migratory locust, Locusta migratoria, one of the most severe insect pests in many regions of the world, and evaluated the role of four CarE genes in insecticide detoxification. Our phylogenetic analysis grouped the 39 CarEs into five different clades including 20 CarEs in clade A, 3 in D, 13 in E, 1 in F and 2 in I. Four CarE genes (LmCesA3, LmCesA20, LmCesD1, LmCesE1), representing three different clades (A, D and E), were selected for further analyses. The transcripts of the four genes were detectable in all the developmental stages and tissues examined. LmCesA3 and LmCesE1 were mainly expressed in the fat bodies and Malpighian tubules, whereas LmCesA20 and LmCesD1 were predominately expressed in the muscles and hemolymph, respectively. The injection of double-stranded RNA (dsRNA) synthesized from each of the four CarE genes followed by the bioassay with each of four insecticides (chlorpyrifos, malathion, carbaryl and deltamethrin) increased the nymphal mortalities by 37.2 and 28.4% in response to malathion after LmCesA20 and LmCesE1 were silenced, respectively. Thus, we proposed that both LmCesA20 and LmCesE1 played an important role in detoxification of malathion in the locust. These results are expected to help researchers reveal the characteristics of diverse CarEs and assess the risk of insecticide resistance conferred by CarEs in the locust and other insect species. PMID:24722667

  6. Cuticular protein LmTwdl1 is involved in molt development of the migratory locust.

    PubMed

    Song, Tian-Qi; Yang, Mei-Ling; Wang, Yan-Li; Liu, Qing; Wang, Hui-Min; Zhang, Jie; Li, Tao

    2016-08-01

    The cuticle, an essential structure for insects, is produced from cuticular proteins and chitin via a series of biochemical reactions. Tweedle genes are important members of the cuticular protein family and have four conserved motifs binding to chitin. Tweedle family genes have been found to play a profound effect on cuticle development. Here, we report that the cuticular protein gene LmTwdl1 of Locusta migratoria belongs to the Tweedle family. In situ hybridization showed that LmTwdl1 is localized to epidermal cells of the cuticle. The expression patterns of LmTwdl1 showed low expression in the cuticle during the early and middle stages of the fifth-instar nymphs; in contrast, its expression rapidly increased in the late stages of fifth-instar nymphs. We performed RNA interference to examine the function of LmTwdl1 in locusts. Silencing of LmTwdl1 resulted in high mortality during the molting process before the next stage. Also, the epicuticle of nymphs failed to molt, tended to be thinner and the arrangement of chitin in the procuticle appeared to be disordered compare to the control group. These results demonstrate that LmTwdl1 plays a critical role in molting, which contributes to a better understanding of the distinct functions of the Tweedle family in locusts. PMID:27430427

  7. Transovarial transmission of Nosema locustae (Microsporida: Nosematidae) in the migratory locust Locusta migratoria migratorioides.

    PubMed

    Raina, S K; Das, S; Rai, M M; Khurad, A M

    1995-01-01

    Nosema locustae, a microsporidian parasite of locusts and grasshoppers, was transovarially transmitted to the progeny of infected Locusta migratoria reared for up to F14 generations. The mortality of infected progeny in each generation was higher than that of uninfected controls and ranged from 67.6% to 95.5%. Infected female survivors transmitted the microsporidium to the progeny via eggs. The developing eggs harboured vegetative stages of N. locustae, and development of the microsporidium occurred during embryonation. Spores accumulated in the yolk and, after blastokinesis, both the yolk and the spores were enclosed in the midgut of the embryo. Germinated spores infected the functional midgut epithelium and invaded internal tissues. The mortality of newly hatched instars was high when embryonic tissue had been infected during development. PMID:7724512

  8. Circadian rhythm changes in toxicity of the insecticide dieldrin on larvae of the migratory locust Locusta migratoria migratorioides.

    PubMed

    Onyeocha, F A; Fuzeau-Braesch, S

    1991-01-01

    Circadian changes in toxicity of the insecticide dieldrin were documented in the larvae (fifth stage) of the migratory locust, Locusta migratoria migratorioides. Insects were housed under light (L): dark (D) = 12:12, with L from 0800 to 2000 h. Topical applications of dieldrin at fixed clock hours, with doses ranging from 0.1 to 8 micrograms/gm body weight, were carried out in a series of experiments on male and female larvae. Twenty-four h after dosing, mortality was recorded to quantify the median lethal dose (LD50) values with reference to time of treatment. Experiments were performed during February, early and late June, and August. Larvae were more susceptible to dieldrin when dosed during the night rather than during the day [analysis of variance (ANOVA); p less than 0.05]. Moreover, female larvae were less susceptible to dieldrin than were male larvae (ANOVA; p less than 0.05). Cosinor analysis revealed circadian rhythms in susceptibility-resistance to the insecticide in all experiments except no. 2. Toxicity was found to be greatest during the nighttime. Cosinor analysis of pooled data of the four experiments documented circadian rhythmicity to toxicity of dieldrin in female but not in male larvae. Regardless of sex, the timing of least susceptibility (greatest resistance and highest LD50 value) to the insecticide, dieldrin, was around 1500. PMID:1797408

  9. Proteomic analysis reveals that COP9 signalosome complex subunit 7A (CSN7A) is essential for the phase transition of migratory locust.

    PubMed

    Tong, Xi-Wen; Chen, Bing; Huang, Li-Hua; Feng, Qi-Li; Kang, Le

    2015-01-01

    The migratory locust displays a reversible, density-dependent transition between the two phases of gregaria and solitaria. This phenomenon is a typical kind of behavior plasticity. Here, we report that COP9 signalosome complex subunit 7A (CSN7A) is involved in the regulation of locust phase transition. Firstly, 90 proteins were identified to express differentially between the two phases by quantitative proteomic analysis. Gregaria revealed higher levels in proteins related to structure formation, melanism and energy metabolism, whereas solitaria had more abundant proteins related to digestion, absorption and chemical sensing. Subsequently, ten proteins including CSN7A were found to reveal differential mRNA expression profiles between the two phases. The CSN7A had higher mRNA level in the gregaria as compared with the solitaria, and the mRNA amount in the gregaria decreased remarkably during the 32 h-isolation. However, the mRNA level in the solitaria kept constant during the crowding rearing. Finally and importantly, RNA interference of CSN7A in gregaria resulted in obvious phase transition towards solitaria within 24 h. It suggests that CSN7A plays an essential role in the transition of gregaria towards solitaria in the migratory locust. To our knowledge, it's the first time to report the role of CSN in behavior plasticity of animals. PMID:26212173

  10. Proteomic analysis reveals that COP9 signalosome complex subunit 7A (CSN7A) is essential for the phase transition of migratory locust

    PubMed Central

    Tong, Xi-Wen; Chen, Bing; Huang, Li-Hua; Feng, Qi-Li; Kang, Le

    2015-01-01

    The migratory locust displays a reversible, density-dependent transition between the two phases of gregaria and solitaria. This phenomenon is a typical kind of behavior plasticity. Here, we report that COP9 signalosome complex subunit 7A (CSN7A) is involved in the regulation of locust phase transition. Firstly, 90 proteins were identified to express differentially between the two phases by quantitative proteomic analysis. Gregaria revealed higher levels in proteins related to structure formation, melanism and energy metabolism, whereas solitaria had more abundant proteins related to digestion, absorption and chemical sensing. Subsequently, ten proteins including CSN7A were found to reveal differential mRNA expression profiles between the two phases. The CSN7A had higher mRNA level in the gregaria as compared with the solitaria, and the mRNA amount in the gregaria decreased remarkably during the 32 h-isolation. However, the mRNA level in the solitaria kept constant during the crowding rearing. Finally and importantly, RNA interference of CSN7A in gregaria resulted in obvious phase transition towards solitaria within 24 h. It suggests that CSN7A plays an essential role in the transition of gregaria towards solitaria in the migratory locust. To our knowledge, it’s the first time to report the role of CSN in behavior plasticity of animals. PMID:26212173

  11. The mechanism for microsporidian parasite suppression of the hindgut bacteria of the migratory locust Locusta migratoria manilensis.

    PubMed

    Tan, Shu-Qian; Zhang, Kai-Qi; Chen, Hong-Xing; Ge, Yang; Ji, Rong; Shi, Wang-Peng

    2015-01-01

    Locusts aggregate into bands of nymphs and swarms of adults that can pose a major threat to crop. Previous studies have shown that infection by the microsporidian parasite Paranosema locustae prevents locust aggregation behavior and we show that gut bacteria, which produce components of locust aggregation pheromones, are substantially reduced in locusts infected with P. locustae. We found that P. locustae could reduce the diversity, abundance and community composition of Locusta migratoria's gut bacteria. The parasite infection was also shown to interrupt the peroxidase activity of locust hindgut. Genome-wide expression analysis showed that the parasite infection suppressed peroxidase mRNA relative expression of locust hindgut, but had no effects on attacin expression and superoxide dismutase at 16 d post-inoculation with 20,000 P. locustae spores. Our findings reveal the mechanisms by which P. locustae impairs bacterial diversity and community structure of Locusta migratoria's gut bacteria. PMID:26612678

  12. The mechanism for microsporidian parasite suppression of the hindgut bacteria of the migratory locust Locusta migratoria manilensis

    PubMed Central

    Tan, Shu-qian; Zhang, Kai-qi; Chen, Hong-xing; Ge, Yang; Ji, Rong; Shi, Wang-peng

    2015-01-01

    Locusts aggregate into bands of nymphs and swarms of adults that can pose a major threat to crop. Previous studies have shown that infection by the microsporidian parasite Paranosema locustae prevents locust aggregation behavior and we show that gut bacteria, which produce components of locust aggregation pheromones, are substantially reduced in locusts infected with P. locustae. We found that P. locustae could reduce the diversity, abundance and community composition of Locusta migratoria’s gut bacteria. The parasite infection was also shown to interrupt the peroxidase activity of locust hindgut. Genome-wide expression analysis showed that the parasite infection suppressed peroxidase mRNA relative expression of locust hindgut, but had no effects on attacin expression and superoxide dismutase at 16 d post-inoculation with 20,000 P. locustae spores. Our findings reveal the mechanisms by which P. locustae impairs bacterial diversity and community structure of Locusta migratoria’s gut bacteria. PMID:26612678

  13. Tissue-Specific Immune Gene Expression in the Migratory Locust, Locusta Migratoria.

    PubMed

    Pulpitel, Tamara; Pernice, Mathieu; Simpson, Stephen J; Ponton, Fleur

    2015-01-01

    The ability of hosts to respond to infection involves several complex immune recognition pathways. Broadly conserved pathogen-associated molecular patterns (PAMPs) allow individuals to target a range of invading microbes. Recently, studies on insect innate immunity have found evidence that a single pathogen can activate different immune pathways across species. In this study, expression changes in immune genes encoding peptidoglycan-recognition protein SA (PGRP-SA), gram-negative binding protein 1 (GNBP1) and prophenoloxidase (ProPO) were investigated in Locusta migratoria, following an immune challenge using injected lipopolysaccharide (LPS) solution from Escherichia coli. Since immune activation might also be tissue-specific, gene expression levels were followed across a range of tissue types. For PGRP-SA, expression increased in response to LPS within all seven of the tissue-types assayed and differed significantly between tissues. Expression of GNBP1 similarly varied across tissue types, yet showed no clear expression difference between LPS-injected and uninfected locusts. Increases in ProPO expression in response to LPS, however, could only be detected in the gut sections. This study has revealed tissue-specific immune response to add a new level of complexity to insect immune studies. In addition to variation in recognition pathways identified in previous works, tissue-specificity should be carefully considered in similar works. PMID:26463191

  14. Primary structure of a structural protein from the cuticle of the migratory locust, Locusta migratoria.

    PubMed Central

    Højrup, P; Andersen, S O; Roepstorff, P

    1986-01-01

    The complete amino acid sequence of a structural protein isolated from pharate cuticle of the locust Locusta migratoria was determined. The protein has an unusual amino acid composition: 42% of the residues are alanine and only 14 of the 20 common amino acid residues are present. The primary structure consists of regions enriched in particular amino acid residues. The N-terminal region and a region close to the C-terminus are enriched in glycine. The rest of the protein is dominated by alanine, except for two short regions enriched in hydrophilic residues. Almost all the proline residues are situated in the alanine-rich regions in a conserved sequence 'A-A-P-A/V'. An internal duplication has taken place covering most of the protein except for the glycine-rich regions. Owing to the unusual features of the protein a combination of automated Edman degradations and plasma-desorption m.s. was used to determine the complete sequence. The protein does not show sequence homology to other proteins, but proteins divided into regions enriched in the same kind of amino acid residues have been isolated from other insect structures. PMID:3790088

  15. The presence of a pregnenolone-binding factor in the copulatory organ of the migratory locust, Locusta migratoria migratorioides R. & F.

    PubMed

    Paesen, G; Novak, F; Swevers, L; De Clerck, D; De Loof, A

    1988-12-01

    The presence of binding sites for nonecdysteroid steroids was investigated in the cytosol of several tissues of the migratory locust, Locusta migratoria migratorioides. Binding of androgens was not observed. Most tissues, however, showed nonsaturable binding of estrogens and in some tissues saturable progestin binding could be demonstrated. A pregnenolone binder, that was found to be present in the male copulatory organ, was further studied. It showed a dissociation constant of 4.4 (+/- 1.6) X 10(-8) M. This is the first report of a nonecdysteroid steroid-binding factor in an insect tissue. PMID:3240850

  16. Remote sensing new model for monitoring the east Asian migratory locust infections based on its breeding circle

    NASA Astrophysics Data System (ADS)

    Han, Xiuzhen; Ma, Jianwen; Bao, Yuhai

    2006-12-01

    Currently the function of operational locust monitor system mainly focused on after-hazards monitoring and assessment, and to found the way effectively to perform early warning and prediction has more practical meaning. Through 2001, 2002 two years continuously field sample and statistics for locusts eggs hatching, nymph growth, adults 3 phases observation, sample statistics and calculation, spectral measurements as well as synchronically remote sensing data processing we raise the view point of Remote Sensing three stage monitor the locust hazards. Based on the point of view we designed remote sensing monitor in three stages: (1) during the egg hitching phase remote sensing can retrieve parameters of land surface temperature (LST) and soil moisture; (2) during nymph growth phase locust increases appetite greatly and remote sensing can calculate vegetation index, leaf area index, vegetation cover and analysis changes; (3) during adult phase the locust move and assembly towards ponds and water ditches as well as less than 75% vegetation cover areas and remote sensing combination with field data can monitor and predicts potential areas for adult locusts to assembly. In this way the priority of remote sensing technology is elaborated effectively and it also provides technique support for the locust monitor system. The idea and techniques used in the study can also be used as reference for other plant diseases and insect pests.

  17. LmCYP4G102: An oenocyte-specific cytochrome P450 gene required for cuticular waterproofing in the migratory locust, Locusta migratoria.

    PubMed

    Yu, Zhitao; Zhang, Xueyao; Wang, Yiwen; Moussian, Bernard; Zhu, Kun Yan; Li, Sheng; Ma, Enbo; Zhang, Jianzhen

    2016-01-01

    Cytochrome P450 superfamily proteins play important roles in detoxification of xenobiotics and during physiological and developmental processes. To contribute to our understanding of this large gene family in insects, we have investigated the function of the cytochrome P450 gene LmCYP4G102 in the migratory locust Locusta migratoria. Suppression of LmCYP4G102 expression by RNA interference (RNAi) does not interfere with moulting but causes rapid loss of body weight - probably due to massive loss of water, and death soon after moulting. Accordingly, maintaining these animals at 90% relative humidity prevented lethality. Consistently, RNAi against LmCYP4G102 provoked a decrease in the content of cuticular alkanes, which as an important fraction of cuticular hydrocarbons have been shown to confer desiccation resistance. In addition, the cuticle of LmCYP4G102-knockdown locusts was fragile and easier deformable than in control animals. Presumably, this phenotype is due to decreased amounts of cuticular water that is reported to modulate cuticle mechanics. Interestingly, LmCYP4G102 was not expressed in the epidermis that produces the cuticle but in the sub-epdiermal hepatocyte-like oenocytes. Together, our results suggest that the oenocyte-specific LmCYP4G102 plays a critical role in the synthesis of cuticular hydrocarbons, which are important for cuticle waterproofing and mechanical stability in L. migratoria. PMID:27444410

  18. LmCYP4G102: An oenocyte-specific cytochrome P450 gene required for cuticular waterproofing in the migratory locust, Locusta migratoria

    PubMed Central

    Yu, Zhitao; Zhang, Xueyao; Wang, Yiwen; Moussian, Bernard; Zhu, Kun Yan; Li, Sheng; Ma, Enbo; Zhang, Jianzhen

    2016-01-01

    Cytochrome P450 superfamily proteins play important roles in detoxification of xenobiotics and during physiological and developmental processes. To contribute to our understanding of this large gene family in insects, we have investigated the function of the cytochrome P450 gene LmCYP4G102 in the migratory locust Locusta migratoria. Suppression of LmCYP4G102 expression by RNA interference (RNAi) does not interfere with moulting but causes rapid loss of body weight - probably due to massive loss of water, and death soon after moulting. Accordingly, maintaining these animals at 90% relative humidity prevented lethality. Consistently, RNAi against LmCYP4G102 provoked a decrease in the content of cuticular alkanes, which as an important fraction of cuticular hydrocarbons have been shown to confer desiccation resistance. In addition, the cuticle of LmCYP4G102-knockdown locusts was fragile and easier deformable than in control animals. Presumably, this phenotype is due to decreased amounts of cuticular water that is reported to modulate cuticle mechanics. Interestingly, LmCYP4G102 was not expressed in the epidermis that produces the cuticle but in the sub-epdiermal hepatocyte-like oenocytes. Together, our results suggest that the oenocyte-specific LmCYP4G102 plays a critical role in the synthesis of cuticular hydrocarbons, which are important for cuticle waterproofing and mechanical stability in L. migratoria PMID:27444410

  19. In vitro incorporation of L-canavanine into vitellogenin of the fat body of the migratory locust Locusta migratoria migratorioides.

    PubMed Central

    Pines, M; Rosenthal, G A; Applebaum, S W

    1981-01-01

    L-Canavanine competes with L-arginine for incorporation into vitellogenin secreted in vitro by the fat body of the female locust Locusta migratoria migratorioides. Incorporation of L-[guanidinooxy-14C]canavanine into vitellogenin has been established unequivocally by combined arginase and urease hydrolyses of the acid hydrolysate of antibody-precipitated canavanyl vitellogenin. Continued exposure of the fat body to canavanine decreases in vitro protein secretion but the proportion of canavanyl vitellogenin to native vitellogenin increases. Canavanine-mediated inhibition of fat body protein secretion is dependent on both the canavanine concentration and the arginine retention by the fat body. Canavanine replaces about 10% of the arginyl residues of canavanyl vitellogenin. The electrophoretic mobility of canavanyl vitellogenin is greater than that of native vitellogenin but the ability of this aberrant protein to react with vitellogenin antibody is unimpaired. Images PMID:6946485

  20. In vitro incorporation of L-canavanine into vitellogenin of the fat body of the migratory locust Locusta migratoria migratorioides.

    PubMed

    Pines, M; Rosenthal, G A; Applebaum, S W

    1981-09-01

    L-Canavanine competes with L-arginine for incorporation into vitellogenin secreted in vitro by the fat body of the female locust Locusta migratoria migratorioides. Incorporation of L-[guanidinooxy-14C]canavanine into vitellogenin has been established unequivocally by combined arginase and urease hydrolyses of the acid hydrolysate of antibody-precipitated canavanyl vitellogenin. Continued exposure of the fat body to canavanine decreases in vitro protein secretion but the proportion of canavanyl vitellogenin to native vitellogenin increases. Canavanine-mediated inhibition of fat body protein secretion is dependent on both the canavanine concentration and the arginine retention by the fat body. Canavanine replaces about 10% of the arginyl residues of canavanyl vitellogenin. The electrophoretic mobility of canavanyl vitellogenin is greater than that of native vitellogenin but the ability of this aberrant protein to react with vitellogenin antibody is unimpaired. PMID:6946485

  1. Juvenile Hormone-Receptor Complex Acts on Mcm4 and Mcm7 to Promote Polyploidy and Vitellogenesis in the Migratory Locust

    PubMed Central

    Song, Jiasheng; Jiang, Feng; Wang, Zhiming; Deng, Shun; Walker, Virginia K.; Zhou, Shutang

    2014-01-01

    Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation. PMID:25340846

  2. Juvenile hormone-receptor complex acts on mcm4 and mcm7 to promote polyploidy and vitellogenesis in the migratory locust.

    PubMed

    Guo, Wei; Wu, Zhongxia; Song, Jiasheng; Jiang, Feng; Wang, Zhiming; Deng, Shun; Walker, Virginia K; Zhou, Shutang

    2014-10-01

    Juvenile hormone (JH), a sesquiterpenoid produced by the corpora allata, coordinates insect growth, metamorphosis, and reproduction. While JH action for the repression of larval metamorphosis has been well studied, the molecular basis of JH in promoting adult reproduction has not been fully elucidated. Methoprene-tolerant (Met), the JH receptor, has been recently shown to mediate JH action during metamorphosis as well as in vitellogenesis, but again, the precise mechanism underlying the latter has been lacking. We have now demonstrated using Met RNAi to phenocopy a JH-deprived condition in migratory locusts, that JH stimulates DNA replication and increases ploidy in preparation for vitellogenesis. Mcm4 and Mcm7, two genes in the DNA replication pathway were expressed in the presence of JH and Met. Depletion of Mcm4 or Mcm7 inhibited de novo DNA synthesis and polyploidization, and resulted in the substantial reduction of vitellogenin mRNA levels as well as severely impaired oocyte maturation and ovarian growth. By using luciferase reporter and electrophoretic mobility shift assays, we have shown that Met directly regulates the transcription of Mcm4 and Mcm7 by binding to upstream consensus sequences with E-box or E-box-like motifs. Our work suggests that the JH-receptor complex acts on Mcm4 and Mcm7 to regulate DNA replication and polyploidy for vitellogenesis and oocyte maturation. PMID:25340846

  3. Indigenous perception and characterization of Yanyanku and Ikpiru: two functional additives for the fermentation of African locust bean.

    PubMed

    Agbobatinkpo, Pélagie B; Azokpota, Paulin; Akissoe, Noël; Kayodé, Polycarpe; Da Gbadji, Rachelle; Hounhouigan, D Joseph

    2011-01-01

    Indigenous perception, processing methods, and physicochemical and microbiological characteristics of Yanyanku and Ikpiru, two additives used to produce fermented African locust bean condiments, Sonru and Iru, were evaluated. According to producers, these additives accelerate the fermentation and soften the texture of the condiments. Yanyanku is produced by spontaneous fermentation with either Hibiscus sabdariffa or Gossypium hirsutum or Adansonia digitata seeds, whereas only Hibiscus sabdariffa seeds are used for Ikpiru. Both additives, with pH values ranging between 6.2 and 10 and Bacillus spores varying between 5.5 and 8.9 Log(10) (CFU/g), could be considered as softening additives or enrichment inocula to produce condiments. PMID:21888591

  4. A Family of CSαβ Defensins and Defensin-Like Peptides from the Migratory Locust, Locusta migratoria, and Their Expression Dynamics during Mycosis and Nosemosis

    PubMed Central

    Zhang, Liwei; Zhang, Pengfei; Zhang, Long

    2016-01-01

    Insect defensins are effector components of the innate defense system. During infection, these peptides may play a role in the control of pathogens by providing protective antimicrobial barriers between epithelial cells and the hemocoel. The cDNAs encoding four defensins of the migratory locust, Locusta migratoria, designated LmDEF 1, 3–5, were identified for the first time by transcriptome-targeted analysis. Three of the members of this CSαβ defensin family, LmDEF 1, 3, and 5, were detected in locust tissues. The pro regions of their sequences have little-shared identities with other insect defensins, though the predicted mature peptides align well with other insect defensins. Phylogenetic analysis indicates a completely novel position of both LmDEF 1 and 3, compared to defensins from hymenopterans. The expression patterns of the genes encoding LmDEFs in the fat body and salivary glands were studied in response to immune-challenge by the microsporidian pathogen Nosema locustae and the fungus Metarhizium anisopliae after feeding or topical application, respectively. Focusing on Nosema-induced immunity, qRT-PCR was employed to quantify the transcript levels of LmDEFs. A higher transcript abundance of LmDEF5 was distributed more or less uniformly throughout the fat body along time. A very low baseline transcription of both LmDEFs 1 and 3 in naïve insects was indicated, and that transcription increases with time or is latent in the fat body or salivary glands of infected nymphs. In the salivary glands, expression of LmDEF3 was 20-40-times higher than in the fat body post-microbial infection. A very low expression of LmDEF3 could be detected in the fat body, but eventually increased with time up to a maximum at day 15. Delayed induction of transcription of these peptides in the fat body and salivary glands 5–15 days post-activation and the differential expression patterns suggest that the fat body/salivary glands of this species are active in the immune response

  5. A Family of CSαβ Defensins and Defensin-Like Peptides from the Migratory Locust, Locusta migratoria, and Their Expression Dynamics during Mycosis and Nosemosis.

    PubMed

    Lv, Mingyue; Mohamed, Amr Ahmed; Zhang, Liwei; Zhang, Pengfei; Zhang, Long

    2016-01-01

    Insect defensins are effector components of the innate defense system. During infection, these peptides may play a role in the control of pathogens by providing protective antimicrobial barriers between epithelial cells and the hemocoel. The cDNAs encoding four defensins of the migratory locust, Locusta migratoria, designated LmDEF 1, 3-5, were identified for the first time by transcriptome-targeted analysis. Three of the members of this CSαβ defensin family, LmDEF 1, 3, and 5, were detected in locust tissues. The pro regions of their sequences have little-shared identities with other insect defensins, though the predicted mature peptides align well with other insect defensins. Phylogenetic analysis indicates a completely novel position of both LmDEF 1 and 3, compared to defensins from hymenopterans. The expression patterns of the genes encoding LmDEFs in the fat body and salivary glands were studied in response to immune-challenge by the microsporidian pathogen Nosema locustae and the fungus Metarhizium anisopliae after feeding or topical application, respectively. Focusing on Nosema-induced immunity, qRT-PCR was employed to quantify the transcript levels of LmDEFs. A higher transcript abundance of LmDEF5 was distributed more or less uniformly throughout the fat body along time. A very low baseline transcription of both LmDEFs 1 and 3 in naïve insects was indicated, and that transcription increases with time or is latent in the fat body or salivary glands of infected nymphs. In the salivary glands, expression of LmDEF3 was 20-40-times higher than in the fat body post-microbial infection. A very low expression of LmDEF3 could be detected in the fat body, but eventually increased with time up to a maximum at day 15. Delayed induction of transcription of these peptides in the fat body and salivary glands 5-15 days post-activation and the differential expression patterns suggest that the fat body/salivary glands of this species are active in the immune response

  6. Identification of new members of the (short) neuropeptide F family in locusts and Caenorhabditis elegans.

    PubMed

    Clynen, Elke; Husson, Steven J; Schoofs, Liliane

    2009-04-01

    Both the long and short neuropeptides F (NPF) represent important families of invertebrate neuropeptides that have been implicated in the regulation of reproduction and feeding behavior. In the present study, two short NPFs (SNRSPS(L/I)R(L/I)RFamide and SPS(L/I)R(L/I)RFamide) were de novo sequenced by mass spectrometry in two major pest insects, the desert locust Schistocerca gregaria and the African migratory locust Locusta migratoria. They are two of the most widespread peptides in the locust neuroendocrine system. A peptide that was previously reported to accelerate egg development in S. gregaria is shown to represent a truncated form of long NPF. This peptide is most likely derived by a novel processing mechanism involving cleavage at RY. In addition, an NPF peptide from the nematode Caenorhabditis elegans was isolated and sequenced by tandem mass spectrometry. PMID:19456328

  7. The role of egg pod foam and rearing conditions of the phase state of the Asian migratory locust Locusta migratoria migratoria (Orthoptera, Acrididae).

    PubMed

    Ben Hamouda, Amel; Ammar, Mohamed; Ben Hamouda, Mohamed Habib; Bouain, Abderrahmen

    2009-07-01

    Coloration phase state, morphometrical ratios and the numbers of mature oocytes of Locusta migratoria migratoria were examined in a series of experiments to determine the means by which phase characteristics are passed to the next generation. Washing with distilled water of eggs from egg pods laid by gregarious crowd-reared females resulted in solitarization of the hatchlings after their isolation, indicating that a factor present in eggs encapsulated in foam is causal to gregarization. Such locusts showed a significant shift towards the typical solitarious body coloration, morphometry and number of mature oocytes as compared to locusts resulting from unwashed eggs. Gregarious coloration, morphometrical ratios and oocyte numbers could be partially restored when hatchlings from washed eggs were regrouped. When gregarious locusts were reared in isolation, they showed a solitary body color, whereas, morphometry and oocyte numbers were not affected by isolation. PMID:19482135

  8. Efficient utilization of aerobic metabolism helps Tibetan locusts conquer hypoxia

    PubMed Central

    2013-01-01

    Background Responses to hypoxia have been investigated in many species; however, comparative studies between conspecific geographical populations at different altitudes are rare, especially for invertebrates. The migratory locust, Locusta migratoria, is widely distributed around the world, including on the high-altitude Tibetan Plateau (TP) and the low-altitude North China Plain (NP). TP locusts have inhabited Tibetan Plateau for over 34,000 years and thus probably have evolved superior capacity to cope with hypoxia. Results Here we compared the hypoxic responses of TP and NP locusts from morphological, behavioral, and physiological perspectives. We found that TP locusts were more tolerant of extreme hypoxia than NP locusts. To evaluate why TP locusts respond to extreme hypoxia differently from NP locusts, we subjected them to extreme hypoxia and compared their transcriptional responses. We found that the aerobic metabolism was less affected in TP locusts than in NP locusts. RNAi disruption of PDHE1β, an entry gene from glycolysis to TCA cycle, increased the ratio of stupor in TP locusts and decreased the ATP content of TP locusts in hypoxia, confirming that aerobic metabolism is critical for TP locusts to maintain activity in hypoxia. Conclusions Our results indicate that TP and NP locusts have undergone divergence in hypoxia tolerance. These findings also indicate that insects can adapt to hypoxic pressure by modulating basic metabolic processes. PMID:24047108

  9. Genotyping of starter cultures of Bacillus subtilis and Bacillus pumilus for fermentation of African locust bean (Parkia biglobosa) to produce Soumbala.

    PubMed

    Ouoba, Labia Irène Ivette; Diawara, Bréhima; Amoa-Awua, Wisdom kofi; Traoré, Alfred Sababénedyo; Møller, Peter Lange

    2004-01-15

    Bacillus spp. are the predominant microorganisms in fermented African locust bean called Soumbala in Burkina Faso. Ten strains selected as potential starter cultures were characterised by PCR amplification of the16S-23S rDNA intergenic transcribed spacer (ITS-PCR), restriction fragment length polymorphism of the ITS-PCR (ITS-PCR RFLP), pulsed field gel electrophoresis (PFGE) and sequencing of the 968-1401 region of the 16S rDNA. In previous studies, the isolates were identified by phenotyping as Bacillus subtilis and Bacillus pumilus. The phenotyping was repeated as a reference in the present study. The ITS-PCR and ITS-PCR RLFP allowed a typing at species level. The PFGE was more discriminative and allowed a typing at strain level. Full agreement with the phenotyping was observed in all cases. The sequencing of the 16S rDNA allowed the identification at species level with an identity from 97% to 100% comparing the sequences to those from the GenBank databases. The desired cultures of B. subtilis and B. pumilus from African locust bean fermentation were distinguished by ITS-PCR and ITS-PCR RLFP from Bacillus cereus and Bacillus sphaericus which sometimes occur in the beginning of the fermentation. PMID:14698101

  10. Genome-wide analysis of transcriptional changes in the thoracic muscle of the migratory locust, Locusta migratoria, exposed to hypobaric hypoxia.

    PubMed

    Zhao, De Jian; Zhang, Zhen Yu; Harrison, Jon; Kang, Le

    2012-11-01

    Hypobaric hypoxia has both beneficial and detrimental effects on living organisms in high altitude regions. The impact of hypobaric hypoxia has been investigated in numerous vertebrates. However, it is still not well characterized how invertebrates respond to hypobaric hypoxia. In this study, we examined the transcriptional profiles of locust thoracic muscles using microarrays to disclose their strategies to cope with hypobaric hypoxia. We found that hypoxia-inducible factor (HIF) and its target genes did not respond significantly to hypobaric hypoxia. As with severe, normobaric hypoxia, mitochondrial activities were systemically suppressed, mainly involving in energy production and mitochondrial biogenesis. The surveillance processes, involving in clearance of dysfunctional proteins in endoplasmic reticulum, were activated, e.g. endoplasmic reticulum-associated degradation, protein glycosylation, and protein folding. In contrast to severe, normobaric hypoxia, glycolysis was suppressed and the pentose phosphate pathway strengthened. Our data suggested that hypobaric hypoxia induced an oxidative stress rather than an energy crisis in locust thoracic muscles. Our research provides a different perspective of biological responses to hypoxia, complementing the well-studied biological responses to extreme, normobaric hypoxia. PMID:22985864

  11. Transcriptomic and proteomic analysis of pre-diapause and non-diapause eggs of migratory locust, Locusta migratoria L. (Orthoptera: Acridoidea).

    PubMed

    Tu, Xiongbing; Wang, Jie; Hao, Kun; Whitman, Douglas W; Fan, Yaoli; Cao, Guangchun; Zhang, Zehua

    2015-01-01

    Low temperature induces diapause in locusts. However, the physiological processes and initiation mechanism of diapause are not well understood. To understand the molecular basis of diapause, 'omics' analyses were performed to examine the differences between diapause and non-diapause eggs at both transcriptional and translational levels. Results indicated that a total of 62,241 mRNAs and 212 proteins were differentially expressed. Among them, 116 transcripts had concurrent transcription and translation profiles. Up-regulated genes related to diapause included glutathiones-S-transferase et al., and down-regulated genes including juvenile hormone esterase-like protein et al. KEGG analysis mapped 7,243 and 99 differentially expressed genes and proteins, to 83 and 25 pathways, respectively. Correlation enriched pathways indicated that there were nine identical pathways related to diapause. Gene Ontology analysis placed these genes and proteins into three categories, and a higher proportion of genes related to metabolism was up-regulated than down-regulated. Furthermore, three up-regulated pathways were linked to cryoprotection. This study demonstrates the applicability of high-throughput omics tools to identify molecules linked to diapause in the locust. In addition, it reveals cellular metabolism in diapause eggs is more active than in non-diapause eggs, and up-regulated enzymes may play roles in cryoprotection and storing energy for diapause and post-diapause stages. PMID:26091374

  12. Microbiological and chemical changes during the fermentation of African locust bean (Parkia biglobosa) to produce afitin, iru and sonru, three traditional condiments produced in Benin.

    PubMed

    Azokpota, P; Hounhouigan, D J; Nago, M C

    2006-04-01

    African locust bean (Parkia biglobosa) was processed to produce afitin, iru and sonru, three different types of condiment from Benin. Whereas the fermentation of African locust bean to produce afitin is carried out for 24 h without using any additive, the fermentation for iru and sonru production takes place for 48 h with adding respectively "iku-iru" and "yanyanku" two traditional malvacene bean-based (Hibiscus sabdariffa) additives. The main microorganisms involved in the fermentation of the three condiments were Bacillus spp., although Staphylococcus spp. was found in lower number. The use of additive seems to enhance the initial Bacillus counts in iru and sonru, but also a slightly higher Staphylococcus count was observed. The number of staphylococci did not exceed 10(2) cfu/g and it was below the detection level at the end of the fermentation (24 h) in afitin; it reached a level of about 10(6) cfu/g at 12-18 h in iru and sonru followed by a decrease to about 5 x 10(4) cfu/g after 48 h of fermentation. The final pH and total basic volatile nitrogen content of iru and sonru are higher than those of afitin. Proximate composition changes are similar in both fermenting iru and sonru, but different in afitin, the latter showing a slight decrease of proteins of about 5% whereas for iru and sonru they increased to about 6%. Ash, crude fat and fibre contents also increased during the fermentation in the three products whereas total carbohydrates decreased significantly. Due to their long fermentation time, iru and sonru are very soft products as they are preferred by some consumers whereas afitin is preferred with cotyledons having less soft texture. PMID:16413077

  13. Altered Immunity in Crowded Locust Reduced Fungal (Metarhizium anisopliae) Pathogenesis

    PubMed Central

    Wang, Yundan; Yang, Pengcheng; Cui, Feng; Kang, Le

    2013-01-01

    The stress of living conditions, similar to infections, alters animal immunity. High population density is empirically considered to induce prophylactic immunity to reduce the infection risk, which was challenged by a model of low connectivity between infectious and susceptible individuals in crowded animals. The migratory locust, which exhibits polyphenism through gregarious and solitary phases in response to population density and displays different resistance to fungal biopesticide (Metarhizium anisopliae), was used to observe the prophylactic immunity of crowded animals. We applied an RNA-sequencing assay to investigate differential expression in fat body samples of gregarious and solitary locusts before and after infection. Solitary locusts devoted at least twice the number of genes for combating M. anisopliae infection than gregarious locusts. The transcription of immune molecules such as pattern recognition proteins, protease inhibitors, and anti-oxidation proteins, was increased in prophylactic immunity of gregarious locusts. The differentially expressed transcripts reducing gregarious locust susceptibility to M. anisopliae were confirmed at the transcriptional and translational level. Further investigation revealed that locust GNBP3 was susceptible to proteolysis while GNBP1, induced by M. anisopliae infection, resisted proteolysis. Silencing of gnbp3 by RNAi significantly shortened the life span of gregarious locusts but not solitary locusts. By contrast, gnbp1 silencing did not affect the life span of both gregarious and solitary locusts after M. anisopliae infection. Thus, the GNBP3-dependent immune responses were involved in the phenotypic resistance of gregarious locusts to fungal infection, but were redundant in solitary locusts. Our results indicated that gregarious locusts prophylactically activated upstream modulators of immune cascades rather than downstream effectors, preferring to quarantine rather than eliminate pathogens to conserve energy

  14. Protein quality, hematological properties and nutritional status of albino rats fed complementary foods with fermented popcorn, African locust bean, and bambara groundnut flour blends

    PubMed Central

    Keshinro, Oluremi Olufunke

    2012-01-01

    The objective of this study was to determine protein quality and hematological properties of infant diets formulated from local food materials. The food materials were obtained locally, fermented, and milled into flour. The flours were mixed as 70% popcorn and 30% African locust bean (FPA), 70% popcorn and 30% bambara groundnut (FPB), and 70% popcorn, 20% bambara groundnut, and 10% African locust bean (FPAB). Proximate analysis, protein quality, hematological properties, and anthropometric measurements of the animals fed with the formulations were investigated. The protein contents of the formulated diets were significantly higher than that of Cerelac (a commercial preparation) (15.75 ± 0.01 g/100 g) and ogi (traditional complementary food) (6.52 ± 0.31 g/100 g). The energy value of FPAB (464.94 ± 1.22 kcal) was higher than those of FPA (441.41 ± 3.05 kcal) and FPB (441.48 ± 3.05 kcal). The biological value (BV) of FPAB (60.20%) was the highest followed by FPB (44.24%) and FPA (41.15%); however, BV of the diets was higher than that of ogi (10.03%) but lower than that of Cerelac (70.43%). Net protein utilization (NPU) of the formulations was 41.16-60.20%, whereas true protein digestibility was 41.05-60.05%. Metabolizable energy (232.98 kcal) and digestible energy (83.69 kcal) of FPAB were the highest, whereas that of FPA had the lowest values. The protein digestibility values corrected for amino acid score of the diets (0.22-0.44) were lower than that of Cerelac (0.52), but higher than that of ogi (0.21). The growth patterns and hematological properties (packed cell volume, red blood cells, hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, and mean corpuscular volume) of the formulated diets were higher than those of ogi, but lower than those of Cerelac. In conclusion, we established that the FPAB food sample was rated best in terms of protein quality over the other formulated diets. Therefore, a FPAB blend may be used as a

  15. Protein quality, hematological properties and nutritional status of albino rats fed complementary foods with fermented popcorn, African locust bean, and bambara groundnut flour blends.

    PubMed

    Ijarotimi, Oluwole Steve; Keshinro, Oluremi Olufunke

    2012-10-01

    The objective of this study was to determine protein quality and hematological properties of infant diets formulated from local food materials. The food materials were obtained locally, fermented, and milled into flour. The flours were mixed as 70% popcorn and 30% African locust bean (FPA), 70% popcorn and 30% bambara groundnut (FPB), and 70% popcorn, 20% bambara groundnut, and 10% African locust bean (FPAB). Proximate analysis, protein quality, hematological properties, and anthropometric measurements of the animals fed with the formulations were investigated. The protein contents of the formulated diets were significantly higher than that of Cerelac (a commercial preparation) (15.75 ± 0.01 g/100 g) and ogi (traditional complementary food) (6.52 ± 0.31 g/100 g). The energy value of FPAB (464.94 ± 1.22 kcal) was higher than those of FPA (441.41 ± 3.05 kcal) and FPB (441.48 ± 3.05 kcal). The biological value (BV) of FPAB (60.20%) was the highest followed by FPB (44.24%) and FPA (41.15%); however, BV of the diets was higher than that of ogi (10.03%) but lower than that of Cerelac (70.43%). Net protein utilization (NPU) of the formulations was 41.16-60.20%, whereas true protein digestibility was 41.05-60.05%. Metabolizable energy (232.98 kcal) and digestible energy (83.69 kcal) of FPAB were the highest, whereas that of FPA had the lowest values. The protein digestibility values corrected for amino acid score of the diets (0.22-0.44) were lower than that of Cerelac (0.52), but higher than that of ogi (0.21). The growth patterns and hematological properties (packed cell volume, red blood cells, hemoglobin, mean corpuscular hemoglobin concentration, mean corpuscular hemoglobin, and mean corpuscular volume) of the formulated diets were higher than those of ogi, but lower than those of Cerelac. In conclusion, we established that the FPAB food sample was rated best in terms of protein quality over the other formulated diets. Therefore, a FPAB blend may be used as a

  16. Physical characterization and sequence identification of the ovary maturating parsin. A new neurohormone purified from the nervous corpora cardiaca of the African locust (Locusta migratoria migratorioides.

    PubMed

    Girardie, J; Richard, O; Huet, J C; Nespoulous, C; Van Dorsselaer, A; Pernollet, J C

    1991-12-18

    A novel neurohormone, which anticipates ovarian maturation, was recently purified using liquid chromatography from the African locust nervous corpora cardiaca. Both its function and production by the pars intercerebralis of Locusta migratoria lead to its name, the ovary maturating parsin (Lom OMP). In this study, the Lom OMP was physically and chemically characterized. Its multiply charged ion spectrum was interpreted as two peaks of quite equal size having molecular masses of 6923.4 Da (major peak) and 6907.3 Da. The Lom OMP presented no periodic secondary structure according to the far ultraviolet circular dichroism spectrum obtained. It is composed of 65 amino acids and included a high concentration of alanine but is devoid of cysteine, isoleucine, methionine, lysine and threonine. The amino acid sequence indicated only one microheterogeneity, observed at position 26, consisted in the replacement of serine by alanine. The calculated Mr of the two acidic isoforms (calculated pHi = 4.87) were found to be in agreement with mass spectrometry measurements. When compared to the sequence libraries, the Lom OMP, the first insect gonadotropic neurohormone, was revealed as an unique protein. PMID:1765072

  17. Male-killing Wolbachia and mitochondrial selective sweep in a migratory African insect

    PubMed Central

    2012-01-01

    Background Numerous recent studies have shown that resident symbiotic microorganisms of insects play a fundamental role in host ecology and evolution. The lepidopteran pest, African armyworm (Spodoptera exempta), is a highly migratory and destructive species found throughout sub-Saharan Africa, that can experience eruptive outbreaks within the space of a single generation, making predicting population dynamics and pest control forecasting extremely difficult. Three strains of Wolbachia have recently been identified infecting this species in populations sampled from Tanzania. In this study, we examined the interaction between Wolbachia pipiensis infections and the co-inherited marker, mtDNA, within populations of armyworm, as a means to investigate the population biology and evolutionary history of Wolbachia and its host. Results A Wolbachia-infected isofemale line was established in the laboratory. Phenotypic studies confirmed the strain wExe1 as a male-killer. Partial sequencing of the mitochondrial COI gene from 164 individual field-collected armyworm of known infection status revealed 17 different haplotypes. There was a strong association between Wolbachia infection status and mtDNA haplotype, with a single dominant haplotype, haplo1 (90.2% prevalence), harbouring the endosymbiont. All three Wolbachia strains were associated with this haplotype. This indicates that Wolbachia may be driving a selective sweep on armyworm haplotype diversity. Despite very strong biological and molecular evidence that the samples represent a single species (including from nuclear 28S gene markers), the 17 haplotypes did not fall into a monophyletic clade within the Spodoptera genus; with six haplotypes (2 each from 3 geographically separate populations) differing by >11% in their nucleotide sequence to the other eleven. Conclusions This study suggests that three strains of Wolbachia may be driving a selective sweep on armyworm haplotype diversity, and that based on COI sequence

  18. Thousand-year-long Chinese time series reveals climatic forcing of decadal locust dynamics.

    PubMed

    Stige, Leif Christian; Chan, Kung-Sik; Zhang, Zhibin; Frank, David; Stenseth, Nils C

    2007-10-01

    For >1,000 years, Chinese officials have recorded the annual abundance of the oriental migratory locust Locusta migratoria manilensis, with the ultimate aim of predicting locust outbreaks. Linking these records with temperature and precipitation reconstructions for the period 957-1956, we show that decadal mean locust abundance is highest during cold and wet periods. These periods coincide with above-average frequencies of both floods and droughts in the lower Yangtze River, phenomena that are associated with locust outbreaks. Our results imply differential ecological responses to interdecadal and interannual climatic variability. Such frequency-dependent effects deserve increased attention in global warming studies. PMID:17878300

  19. Role of remote sensing in desert locust early warning

    NASA Astrophysics Data System (ADS)

    Cressman, Keith

    2013-01-01

    Desert locust (Schistocerca gregaria, Forskål) plagues have historically had devastating consequences on food security in Africa and Asia. The current strategy to reduce the frequency of plagues and manage desert locust infestations is early warning and preventive control. To achieve this, the Food and Agriculture Organization of the United Nations operates one of the oldest, largest, and best-known migratory pest monitoring systems in the world. Within this system, remote sensing plays an important role in detecting rainfall and green vegetation. Despite recent technological advances in data management and analysis, communications, and remote sensing, monitoring desert locusts and preventing plagues in the years ahead will continue to be a challenge from a geopolitical and financial standpoint for affected countries and the international donor community. We present an overview of the use of remote sensing in desert locust early warning.

  20. Trehalose inhibits the release of adipokinetic hormones from the corpus cardiacum in the African migratory locust, Locusta migratoria, at the level of the adipokinetic cells.

    PubMed

    Passier, P C; Vullings, H G; Diederen, J H; Van der Horst, D J

    1997-05-01

    The effect of trehalose at various concentrations on the release of adipokinetic hormones (AKHs) from the adipokinetic cells in the glandular part of the corpus cardiacum of Locusta migratoria was studied in vitro. Pools of five corpora cardiaca or pools of five glandular parts of corpora cardiaca were incubated in a medium containing different concentrations of trehalose in the absence or presence of AKH-release-inducing agents. It was demonstrated that trehalose inhibits spontaneous release of AKH I in a dose-dependent manner. At a concentration of 80 mM, which is the concentration found in the hemolymph at rest, trehalose significantly decreased the release of AKH I induced by 100 microM locustatachykinin 1, 10 microM 3-isobutyl-1-methylxanthine (IBMX) or high potassium concentrations. The specificity of the effect of trehalose was studied by incubating pools of corpora cardiaca with the non-hydrolyzable disaccharide sucrose or with glucose, the degradation product of trehalose, both in the presence and absence of 10 microM IBMX. Sucrose had no effect at all on the release of AKH I, whereas glucose strongly inhibited its release. The results point to the inhibitory effect of trehalose on the release of AKH I being exerted, at least partly, at the level of the adipokinetic cells, possibly after its conversion into glucose. The data presented in this study support the hypothesis that in vivo the relatively high concentration of trehalose (80 mM) at rest strongly inhibits the release of AKHs. At the onset of flight, the demand for energy substrates exceeds the amount of trehalose that can be mobilized from the fat body and consequently the trehalose concentration in the hemolymph decreases. This relieves the inhibitory effect of trehalose on the release of AKHs, which in turn mobilize lipids from the fat body. PMID:9166120

  1. Dietary influences over proliferating cell nuclear antigen expression in the locust midgut.

    PubMed

    Zudaire, E; Simpson, S J; Illa, I; Montuenga, L M

    2004-06-01

    We have studied the influence of variations in dietary protein (P) and digestible carbohydrate (C), the quantity of food eaten, and insect age during the fifth instar on the expression of the proliferating cell nuclear antigen (PCNA) in the epithelial cells of the midgut (with special reference to the midgut caeca) in the African migratory locust, Locusta migratoria. Densitometric analysis of PCNA-immunostained cells was used as an indirect measure of the levels of expression of PCNA, and a PCNA cellular index (PCNA-I) was obtained. Measurements of the DNA content of the cells have also been carried out by means of microdensitometry of Feulgen-stained, thick sections of midgut. A comparison between the PCNA nuclear level and the DNA content was performed. The PCNA levels were significantly different among the cells of the five regions studied: caeca, anterior ventricle, medial ventricle, posterior ventricle and ampullae of the Malpighian tubules. We have studied in more detail the region with highest PCNA-I, i.e. the caeca. The quality and the quantity of food eaten under ad libitum conditions were highly correlated with both the PCNA and DNA levels in the caeca cells. Locusts fed a diet with a close to optimal P:C content (P 21%, C 21%) showed the highest PCNA and DNA content. In locusts fed a food that also contained a 1:1 ratio of P to C but was diluted three-fold by addition of indigestible cellulose (P 7%, C 7%), a compensatory increase in consumption was critical to maintaining PCNA levels. Our measurements also showed that the nuclear DNA content of the mature and differentiated epithelial cells was several-fold higher than the levels in the undifferentiated stem cells of the regenerative nests. These results, combined with the low number of mitotic figures found in the regenerative nests of the caeca and the marked variation in PCNA levels among groups, suggest that some type of DNA endoreduplication process may be taking place. Our data also indicate that

  2. African Vultures Don’t Follow Migratory Herds: Scavenger Habitat Use Is Not Mediated by Prey Abundance

    PubMed Central

    Kendall, Corinne J.; Virani, Munir Z.; Hopcraft, J. Grant C.; Bildstein, Keith L.; Rubenstein, Daniel I.

    2014-01-01

    The ongoing global decline in vulture populations raises major conservation concerns, but little is known about the factors that mediate scavenger habitat use, in particular the importance of abundance of live prey versus prey mortality. We test this using data from the Serengeti-Mara ecosystem in East Africa. The two hypotheses that prey abundance or prey mortality are the main drivers of vulture habitat use provide alternative predictions. If vultures select areas based only on prey abundance, we expect tracked vultures to remain close to herds of migratory wildebeest regardless of season. However, if vultures select areas where mortality rates are greatest then we expect vultures to select the driest regions, where animals are more likely to die of starvation, and to be attracted to migratory wildebeest only during the dry season when wildebeest mortality is greatest. We used data from GSM-GPS transmitters to assess the relationship between three vulture species and migratory wildebeest in the Mara-Serengeti ecosystem. Results indicate that vultures preferentially cluster around migratory herds only during the dry season, when herds experience their highest mortality. Additionally during the wet season, Ruppell’s and Lappet-faced vultures select relatively dry areas, based on Normalized Difference Vegetation Index, whereas White-backed vultures preferred wetter areas during the wet season. Differences in habitat use among species may mediate coexistence in this scavenger guild. In general, our results suggest that prey abundance is not the primary driver of avian scavenger habitat use. The apparent reliance of vultures on non-migratory ungulates during the wet season has important conservation implications for vultures in light of on-going declines in non-migratory ungulate species and use of poisons in unprotected areas. PMID:24421887

  3. African vultures don't follow migratory herds: scavenger habitat use is not mediated by prey abundance.

    PubMed

    Kendall, Corinne J; Virani, Munir Z; Hopcraft, J Grant C; Bildstein, Keith L; Rubenstein, Daniel I

    2014-01-01

    The ongoing global decline in vulture populations raises major conservation concerns, but little is known about the factors that mediate scavenger habitat use, in particular the importance of abundance of live prey versus prey mortality. We test this using data from the Serengeti-Mara ecosystem in East Africa. The two hypotheses that prey abundance or prey mortality are the main drivers of vulture habitat use provide alternative predictions. If vultures select areas based only on prey abundance, we expect tracked vultures to remain close to herds of migratory wildebeest regardless of season. However, if vultures select areas where mortality rates are greatest then we expect vultures to select the driest regions, where animals are more likely to die of starvation, and to be attracted to migratory wildebeest only during the dry season when wildebeest mortality is greatest. We used data from GSM-GPS transmitters to assess the relationship between three vulture species and migratory wildebeest in the Mara-Serengeti ecosystem. Results indicate that vultures preferentially cluster around migratory herds only during the dry season, when herds experience their highest mortality. Additionally during the wet season, Ruppell's and Lappet-faced vultures select relatively dry areas, based on Normalized Difference Vegetation Index, whereas White-backed vultures preferred wetter areas during the wet season. Differences in habitat use among species may mediate coexistence in this scavenger guild. In general, our results suggest that prey abundance is not the primary driver of avian scavenger habitat use. The apparent reliance of vultures on non-migratory ungulates during the wet season has important conservation implications for vultures in light of on-going declines in non-migratory ungulate species and use of poisons in unprotected areas. PMID:24421887

  4. MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts.

    PubMed

    He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

    2016-01-19

    Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276-induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

  5. MicroRNA-276 promotes egg-hatching synchrony by up-regulating brm in locusts

    PubMed Central

    He, Jing; Chen, Qianquan; Wei, Yuanyuan; Jiang, Feng; Yang, Meiling; Hao, Shuguang; Guo, Xiaojiao; Chen, Dahua; Kang, Le

    2016-01-01

    Developmental synchrony, the basis of uniform swarming, migration, and sexual maturation, is an important strategy for social animals to adapt to variable environments. However, the molecular mechanisms underlying developmental synchrony are largely unexplored. The migratory locust exhibits polyphenism between gregarious and solitarious individuals, with the former displaying more synchronous sexual maturation and migration than the latter. Here, we found that the egg-hatching time of gregarious locusts was more uniform compared with solitarious locusts and that microRNA-276 (miR-276) was expressed significantly higher in both ovaries and eggs of gregarious locusts than in solitarious locusts. Interestingly, inhibiting miR-276 in gregarious females and overexpressing it in solitarious females, respectively, caused more heterochronic and synchronous hatching of progeny eggs. Moreover, miR-276 directly targeted a transcription coactivator gene, brahma (brm), resulting in its up-regulation. Knockdown of brm not only resulted in asynchronous egg hatching in gregarious locusts but also impaired the miR-276–induced synchronous egg hatching in solitarious locusts. Mechanistically, miR-276 mediated brm activation in a manner that depended on the secondary structure of brm, namely, a stem-loop around the binding site of miR-276. Collectively, our results unravel a mechanism by which miR-276 enhances brm expression to promote developmental synchrony and provide insight into regulation of developmental homeostasis and population sustaining that are closely related to biological synchrony. PMID:26729868

  6. Effects of food nutrient content, insect age and stage in the feeding cycle on the FMRFamide immunoreactivity of diffuse endocrine cells in the locust gut.

    PubMed

    Zudaire, E; Simpson, S J; Montuenga, L M

    1998-11-01

    We have studied the influence of variations in dietary protein and digestible carbohydrate content, of insect age and of time during the feeding cycle on the endocrine cells of the ampullar region of the midgut in the African migratory locust Locusta migratoria L. Morphometric analysis of FMRFamide-like immunoreactivity was used as an indirect measure of the amount of FMRFamide-related peptides (FaRPs) stored in the gut endocrine cells. There was a highly significant correlation between FaRP content and the nutritional quality of the food, measured relative to the concentrations and ratio of protein to digestible carbohydrate in a nutritionally optimal diet. The direction of the relationship between FaRP content and diet quality varied with age during the fifth stadium. On day 1, FaRP levels increased with the nutritional quality of the food, while on day 4 the opposite relationship was observed. Release of peptide was triggered by the onset of a meal during ad libitum feeding, with cell FaRP levels returning to premeal values within 15 min of the meal ending. The results also suggested that cell contents were released during food deprivation beyond the normal intermeal interval. Locusts switched for a single meal during ad libitum feeding on day 4 from a low- to a high-carbohydrate food did not respond by reducing endocrine cell FaRP content. Our results show a relationship between the diffuse gut endocrine system and feeding and nutrition in locusts. The ampullar endocrine cells are in three-way contact with the midgut luminal contents, with the primary urine from the Malpighian tubules and with the haemolymph. They are thus ideally positioned to play an integrative receptor-secretory function in the regulation of a variety of post-ingestive processes, such as enzyme secretion, absorption, gut motility or nutrient metabolism. PMID:9866881

  7. Locusts and remote sensing: a review

    NASA Astrophysics Data System (ADS)

    Latchininsky, Alexandre V.

    2013-01-01

    A dozen species of locusts (Orthoptera: Acrididae) are a major threat to food security worldwide. Their outbreaks occur on every continent except Antarctica, threatening the livelihood of 10% of the world's population. The locusts are infamous for their voracity, polyphagy, and capacity for long-distance migrations. Decades of research revealed very complex bio-ecology of locusts. They exist in two, inter-convertible and density-dependent states, or "phases." Despite the evident progress in understanding locust behavior, our ability to predict and manage locust outbreaks remains insufficient, as evidenced by locust plagues still occurring during the 21st century. One of the main reasons is that locusts typically inhabit remote and scarcely populated areas, and their distribution ranges often spread across continents. This creates tremendous obstacles for locust population monitoring and control. Traditional ground locust surveys are inadequate to address the enormous spatial scale of the locust problem in a limited window of time dictated by the pest's development. Remote sensing (satellite information) appears a promising tool in locust monitoring. Satellite data are increasingly used for monitoring and forecasting two locust species, the desert and the Australian plague locust. However, applications of this geospatial technology to other locust species remain rare.

  8. A stochastic lattice model for locust outbreak

    NASA Astrophysics Data System (ADS)

    Kizaki, Shinya; Katori, Makoto

    The locust is a kind of grasshoppers. Gregarious locusts form swarms and can migrate over large distances and they spread and damage a large area (locust outbreak). When the density is low, each of locusts behaves as an individual insect (solitary phase). As locusts become crowded, they become to act as a part of a group (gregarious phase) as a result of interactions among them. Modeling of this phenomenon is a challenging problem of statistical physics. We introduce a stochastic cellular automaton model of locust population-dynamics on lattices. Change of environmental conditions by seasonal migration is a key factor in gregarisation of locusts and we take it into account by changing the lattice size periodically. We study this model by computer simulations and discuss the locust outbreak as a cooperative phenomena.

  9. Late Pliocene and Quaternary Eurasian locust infestations in the Canary Archipelago

    USGS Publications Warehouse

    Meco, J.; Muhs, D.R.; Fontugne, M.; Ramos, A.J.; Lomoschitz, A.; Patterson, D.

    2011-01-01

    The Canary Archipelago has long been a sensitive location to record climate changes of the past. Interbedded with its basalt lavas are marine deposits from the principal Pleistocene interglacials, as well as aeolian sands with intercalated palaeosols. The palaeosols contain African dust and innumerable relict egg pods of a temperate-region locust (cf. Dociostaurus maroccanusThunberg 1815). New ecological and stratigraphical information reveals the geological history of locust plagues (or infestations) and their palaeoclimatic significance. Here, we show that the first arrival of the plagues to the Canary Islands from Africa took place near the end of the Pliocene, ca. 3Ma, and reappeared with immense strength during the middle Late Pleistocene preceding MIS (marine isotope stage) 11 (ca. 420ka), MIS 5.5 (ca. 125ka) and probably during other warm interglacials of the late Middle Pleistocene and the Late Pleistocene. During the Early Holocene, locust plagues may have coincided with a brief cool period in the current interglacial. Climatically, locust plagues on the Canaries are a link in the chain of full-glacial arid-cold climate (calcareous dunes), early interglacial arid-sub-humid climate (African dust inputs and locust plagues), peak interglacial warm-humid climate (marine deposits with Senegalese fauna), transitional arid-temperate climate (pedogenic calcretes), and again full-glacial arid-cold climate (calcareous dunes) oscillations. During the principal interglacials of the Pleistocene, the Canary Islands recorded the migrations of warm Senegalese marine faunas to the north, crossing latitudes in the Euro-African Atlantic. However, this northward marine faunal migration was preceded in the terrestrial realm by interglacial infestations of locusts. ??? Locust plagues, Canary Islands, Late Pliocene, Pleistocene, Holocene, palaeoclimatology. ?? 2010 The Authors, Lethaia ?? 2010 The Lethaia Foundation.

  10. Evidence for the expression of abundant microRNAs in the locust genome

    PubMed Central

    Wang, Yanli; Jiang, Feng; Wang, Huimin; Song, Tianqi; Wei, Yuanyuan; Yang, Meiling; Zhang, Jianzhen; Kang, Le

    2015-01-01

    Substantial accumulation of neutral sequences accounts for genome size expansion in animal genomes. Numerous novel microRNAs (miRNAs), which evolve in a birth and death manner, are considered evolutionary neutral sequences. The migratory locust is an ideal model to determine whether large genomes contain abundant neutral miRNAs because of its large genome size. A total of 833 miRNAs were discovered, and several miRNAs were randomly chosen for validation by Northern blot and RIP-qPCR. Three additional verification methods, namely, processing-dependent methods of miRNA biogenesis using RNAi, evolutionary comparison with closely related species, and evidence supported by tissue-specific expression, were applied to provide compelling results that support the authenticity of locust miRNAs. We observed that abundant local duplication events of miRNAs, which were unique in locusts compared with those in other insects with small genome sizes, may be responsible for the substantial acquisition of miRNAs in locusts. Together, multiple evidence showed that the locust genome experienced a burst of miRNA acquisition, suggesting that genome size expansion may have considerable influences of miRNA innovation. These results provide new insight into the genomic dynamics of miRNA repertoires under genome size evolution. PMID:26329925

  11. Periodic temperature-associated drought/flood drives locust plagues in China.

    PubMed

    Zhang, Zhibin; Cazelles, Bernard; Tian, Huidong; Stige, Leif Christian; Bräuning, Achim; Stenseth, Nils Chr

    2009-03-01

    Global warming is currently of great concern. Yet the ecological effects of low-frequency climate variations remain largely unknown. Recent analyses of interdecadal variability in population abundance of the Oriental migratory locust (Locusta migratoria manilensis) in China have revealed negative associations with temperature and positive associations with Yangtze drought and flood frequencies during the past millennium (AD 957-1956). In order to shed new light on the causal relationships between locust abundance, floods, droughts and temperature in ancient China, we used wavelet analysis to explore how the coherencies between the different variables at different frequencies have been changed during the past millennium. We find consistent in-phase coherencies between locusts and drought/flood frequencies, and out-of-phase coherencies between locusts and temperature and between drought/flood and temperature at period components of 160-170 years. Similar results are obtained when historical data of drought/flood frequencies of the Yangtze Delta region are used, despite flood data showing a weak and somewhat inconsistent association with other factors. We suggest that previously unreported periodic cooling of 160-170-year intervals dominate climatic variability in China through the past millennium, the cooling events promoting locust plagues by enhancing temperature-associated drought/flood events. Our results signify a rare example of possible benign effects of global warming on the regional risk of natural disasters such as flood/drought events and outbreaks of pest insects. PMID:19033144

  12. Fuel ethanol from black locust

    SciTech Connect

    Kamdem, P.D.

    1993-12-31

    Black locust (Robinia psudoacacia) chips from single clone at different ages (1 to 20 years) were analyzed in terms of lignin, extractives, and carbohydrate content. Samples with high carbohydrate content were chosen for liquid ethanol conversion, by using a simultaneous saccharification fermentation process. To achieve efficient fermentation, samples were extracted with benzene and ethanol, and then treated with a 1% sulfuric acid solution for 10 minutes at 130{degrees}C. Celluclast 1.5L and Novozym 188 were used to reduce cellulose into glucose and yeasts such as B. clausenii and/or S. cerevisiae to ferment available sugars. Preliminary results indicate a negative influence of extractives present in black locust. Those extractives are mainly flavonoids (Robinetin an dihydrorobinetin) which are relatively toxic to some wood destroying organisms. Older trees give low ethanol yield and high ash content.

  13. Unveiling the mechanism by which microsporidian parasites prevent locust swarm behavior

    PubMed Central

    Shi, Wangpeng; Guo, Yang; Xu, Chuan; Tan, Shuqian; Miao, Jing; Feng, Yanjie; Zhao, Hong; St. Leger, Raymond J.; Fang, Weiguo

    2014-01-01

    Locusts are infamous for their ability to aggregate into gregarious migratory swarms that pose a major threat to food security. Aggregation is elicited by an interplay of visual, tactile, and chemical stimuli, but the aggregation pheromone in feces is particularly important. Infection by the microsporidian parasite Paranosema (Nosema) locustae is known to inhibit aggregation of solitary Locusta migratoria manilensis and to induce gregarious locusts to shift back to solitary behavior. Here we suggest that P. locustae achieves this effect by acidifying the hindgut and modulating the locust immune response, which suppresses the growth of the hindgut bacteria that produce aggregation pheromones. This in turn reduces production of the neurotransmitter serotonin that initiates gregarious behavior. Healthy L. migratoria manilensis exposed to olfactory stimuli from parasite-infected locusts also produced significantly less serotonin, reducing gregarization. P. locustae also suppresses biosynthesis of the neurotransmitter dopamine that maintains gregarization. Our findings reveal the mechanisms by which P. locustae reduces production of aggregation pheromone and blocks the initiation and maintainence of gregarious behavior. PMID:24474758

  14. Control of tumbling during the locust jump

    PubMed Central

    Cofer, David; Cymbalyuk, Gennady; Heitler, William J.; Edwards, Donald H.

    2010-01-01

    Locust can jump precisely to a target, yet they can also tumble during the trajectory. We propose two mechanisms that would allow the locust to control tumbling during the jump. The first is that prior to the jump, locusts adjust the pitch of their body to move the center of mass closer to the intended thrust vector. The second is that contraction of the dorsolongitudinal muscles during the jump will produce torques that counter the torque produced by thrust. We found that locusts increased their take-off angle as the initial body pitch increased, and that little tumbling occurred for jumps that observed this relationship. Simulations of locust jumping demonstrated that a pitch versus take-off angle relationship that minimized tumbling in simulated jumps was similar to the relationship observed in live locusts. Locusts were strongly biased to pitch head-upward, and performed dorsiflexions far more often than ventral flexions. The direction and magnitude of tumbling could be controlled in simulations by adjusting the tension in the dorsolongitudinal muscles. These mechanisms allowed the simulations to match the data from the live animals. Control of tumbling was also found to influence the control of jump elevation. The bias to pitch head-upwards may have an evolutionary advantage when evading a predator and so make control of tumbling important for the locust. PMID:20833932

  15. Control of tumbling during the locust jump.

    PubMed

    Cofer, David; Cymbalyuk, Gennady; Heitler, William J; Edwards, Donald H

    2010-10-01

    Locust can jump precisely to a target, yet they can also tumble during the trajectory. We propose two mechanisms that would allow the locust to control tumbling during the jump. The first is that prior to the jump, locusts adjust the pitch of their body to move the center of mass closer to the intended thrust vector. The second is that contraction of the dorsolongitudinal muscles during the jump will produce torques that counter the torque produced by thrust. We found that locusts increased their take-off angle as the initial body pitch increased, and that little tumbling occurred for jumps that observed this relationship. Simulations of locust jumping demonstrated that a pitch versus take-off angle relationship that minimized tumbling in simulated jumps was similar to the relationship observed in live locusts. Locusts were strongly biased to pitch head-upward, and performed dorsiflexions far more often than ventral flexions. The direction and magnitude of tumbling could be controlled in simulations by adjusting the tension in the dorsolongitudinal muscles. These mechanisms allowed the simulations to match the data from the live animals. Control of tumbling was also found to influence the control of jump elevation. The bias to pitch head-upwards may have an evolutionary advantage when evading a predator and so make control of tumbling important for the locust. PMID:20833932

  16. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  17. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  18. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  19. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree, Ceratonia siliqua (Linne), a leguminous...

  20. 21 CFR 184.1343 - Locust (carob) bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Locust (carob) bean gum. 184.1343 Section 184.1343... Listing of Specific Substances Affirmed as GRAS § 184.1343 Locust (carob) bean gum. (a) Locust (carob) bean gum is primarily the macerated endosperm of the seed of the locust (carob) bean tree,...

  1. Egg hatching of two locusts, Schistocerca gregaria and Locusta migratoria, in response to light and temperature cycles.

    PubMed

    Nishide, Yudai; Tanaka, Seiji; Saeki, Shinjiro

    2015-05-01

    The present study showed that the eggs of the desert locust, Schistocerca gregaria, and the migratory locust, Locusta migratoria, responded to photoperiod by hatching when placed on sand in the laboratory. S. gregaria mainly hatched during the dark phase and L. migratoria during the light phase. The importance of light as a hatching cue depended on the magnitude of the temperature change during the thermoperiod; photoperiod played a more important role in the control of hatching time in both species when the magnitude of the temperature change was small. In addition, the eggs of the two species that were covered with sand did not respond to photoperiod and hatched during both the light and dark phases, indicating that light did not penetrate through the sand. Because locust eggs are normally laid as egg pods and a foam plug is deposited between the egg mass and the ground surface, we tested a possibility that naturally deposited eggs perceived light through the foam plug. The eggs that were deposited and left undisturbed in the sand hatched during the light and dark phases at similar frequencies. These results suggest that the eggs of both locust species responded to light and controlled their hatching timing accordingly but would not use light as a hatching cue in the field. The evolutionary significance of the ability of eggs to respond to light in these locusts was discussed. PMID:25796138

  2. Object-based locust habitat mapping using high-resolution multispectral satellite data in the southern Aral Sea basin

    NASA Astrophysics Data System (ADS)

    Navratil, Peter; Wilps, Hans

    2013-01-01

    Three different object-based image classification techniques are applied to high-resolution satellite data for the mapping of the habitats of Asian migratory locust (Locusta migratoria migratoria) in the southern Aral Sea basin, Uzbekistan. A set of panchromatic and multispectral Système Pour l'Observation de la Terre-5 satellite images was spectrally enhanced by normalized difference vegetation index and tasseled cap transformation and segmented into image objects, which were then classified by three different classification approaches: a rule-based hierarchical fuzzy threshold (HFT) classification method was compared to a supervised nearest neighbor classifier and classification tree analysis by the quick, unbiased, efficient statistical trees algorithm. Special emphasis was laid on the discrimination of locust feeding and breeding habitats due to the significance of this discrimination for practical locust control. Field data on vegetation and land cover, collected at the time of satellite image acquisition, was used to evaluate classification accuracy. The results show that a robust HFT classifier outperformed the two automated procedures by 13% overall accuracy. The classification method allowed a reliable discrimination of locust feeding and breeding habitats, which is of significant importance for the application of the resulting data for an economically and environmentally sound control of locust pests because exact spatial knowledge on the habitat types allows a more effective surveying and use of pesticides.

  3. MicroRNA-133 Inhibits Behavioral Aggregation by Controlling Dopamine Synthesis in Locusts

    PubMed Central

    Wang, Yanli; Guo, Xiaojiao; He, Jing; Kang, Le

    2014-01-01

    Phenotypic plasticity is ubiquitous and primarily controlled by interactions between environmental and genetic factors. The migratory locust, a worldwide pest, exhibits pronounced phenotypic plasticity, which is a population density-dependent transition that occurs between the gregarious and solitary phases. Genes involved in dopamine synthesis have been shown to regulate the phase transition of locusts. However, the function of microRNAs in this process remains unknown. In this study, we report the participation of miR-133 in dopamine production and the behavioral transition by negatively regulating two critical genes, henna and pale, in the dopamine pathway. miR-133 participated in the post-transcriptional regulation of henna and pale by binding to their coding region and 3′ untranslated region, respectively. miR-133 displayed cellular co-localization with henna/pale in the protocerebrum, and its expression in the protocerebrum was negatively correlated with henna and pale expression. Moreover, miR-133 agomir delivery suppressed henna and pale expression, which consequently decreased dopamine production, thus resulting in the behavioral shift of the locusts from the gregarious phase to the solitary phase. Increasing the dopamine content could rescue the solitary phenotype, which was induced by miR-133 agomir delivery. Conversely, miR-133 inhibition increased the expression of henna and pale, resulting in the gregarious-like behavior of solitary locusts; this gregarious phenotype could be rescued by RNA interference of henna and pale. This study shows the novel function and modulation pattern of a miRNA in phenotypic plasticity and provides insight into the underlying molecular mechanisms of the phase transition of locusts. PMID:24586212

  4. Locust Collective Motion and Its Modeling.

    PubMed

    Ariel, Gil; Ayali, Amir

    2015-12-01

    Over the past decade, technological advances in experimental and animal tracking techniques have motivated a renewed theoretical interest in animal collective motion and, in particular, locust swarming. This review offers a comprehensive biological background followed by comparative analysis of recent models of locust collective motion, in particular locust marching, their settings, and underlying assumptions. We describe a wide range of recent modeling and simulation approaches, from discrete agent-based models of self-propelled particles to continuous models of integro-differential equations, aimed at describing and analyzing the fascinating phenomenon of locust collective motion. These modeling efforts have a dual role: The first views locusts as a quintessential example of animal collective motion. As such, they aim at abstraction and coarse-graining, often utilizing the tools of statistical physics. The second, which originates from a more biological perspective, views locust swarming as a scientific problem of its own exceptional merit. The main goal should, thus, be the analysis and prediction of natural swarm dynamics. We discuss the properties of swarm dynamics using the tools of statistical physics, as well as the implications for laboratory experiments and natural swarms. Finally, we stress the importance of a combined-interdisciplinary, biological-theoretical effort in successfully confronting the challenges that locusts pose at both the theoretical and practical levels. PMID:26656851

  5. Locust Collective Motion and Its Modeling

    PubMed Central

    Ariel, Gil; Ayali, Amir

    2015-01-01

    Over the past decade, technological advances in experimental and animal tracking techniques have motivated a renewed theoretical interest in animal collective motion and, in particular, locust swarming. This review offers a comprehensive biological background followed by comparative analysis of recent models of locust collective motion, in particular locust marching, their settings, and underlying assumptions. We describe a wide range of recent modeling and simulation approaches, from discrete agent-based models of self-propelled particles to continuous models of integro-differential equations, aimed at describing and analyzing the fascinating phenomenon of locust collective motion. These modeling efforts have a dual role: The first views locusts as a quintessential example of animal collective motion. As such, they aim at abstraction and coarse-graining, often utilizing the tools of statistical physics. The second, which originates from a more biological perspective, views locust swarming as a scientific problem of its own exceptional merit. The main goal should, thus, be the analysis and prediction of natural swarm dynamics. We discuss the properties of swarm dynamics using the tools of statistical physics, as well as the implications for laboratory experiments and natural swarms. Finally, we stress the importance of a combined-interdisciplinary, biological-theoretical effort in successfully confronting the challenges that locusts pose at both the theoretical and practical levels. PMID:26656851

  6. Arousal shifts in quiescent locusts

    PubMed

    Schuppe; Burrows

    1998-06-01

    Locusts are usually quiescent at night, but this state can be interrupted by spontaneous periods of motor activity, or arousals, that can also be induced by exposure to light stimuli. To investigate whether repeated arousing stimulation has any lasting effect on behaviour, locusts were confronted at night with a series of 1 s light stimuli. Groups of three stimuli at intervals of 60 s were repeated 11 times at 10 min intervals during the first experimental night, and three stimuli at intervals of 90 s were repeated at 15 min intervals during the next night. Arousals and the effects of stimulation were monitored as changes in the spike activity of muscles in the basal part (the scapus) of the right antenna. In the early part of the night preceding the presentation of the light stimuli, neither 60 s nor 90 s periods were present as significant peaks in spontaneous changes in spike activity. The initial stimulus of a series evoked an arousal response that habituated on repetition of the stimulus. The end of the series of stimuli was followed by changes in spike activity that tended to have the same periodicity as the preceding stimuli. Furthermore, a single light stimulus at the end of the night evoked changes in spike activity that again tended to have the same periodicity as the preceding entraining stimuli. Repeated stimulation may therefore establish a memory trace for the period of stimulation that can be recalled either spontaneously or by the application of an appropriate external stimulus. PMID:9576882

  7. Visual Coding in Locust Photoreceptors

    PubMed Central

    Faivre, Olivier; Juusola, Mikko

    2008-01-01

    Information capture by photoreceptors ultimately limits the quality of visual processing in the brain. Using conventional sharp microelectrodes, we studied how locust photoreceptors encode random (white-noise, WN) and naturalistic (1/f stimuli, NS) light patterns in vivo and how this coding changes with mean illumination and ambient temperature. We also examined the role of their plasma membrane in shaping voltage responses. We found that brightening or warming increase and accelerate voltage responses, but reduce noise, enabling photoreceptors to encode more information. For WN stimuli, this was accompanied by broadening of the linear frequency range. On the contrary, with NS the signaling took place within a constant bandwidth, possibly revealing a ‘preference’ for inputs with 1/f statistics. The faster signaling was caused by acceleration of the elementary phototransduction current - leading to bumps - and their distribution. The membrane linearly translated phototransduction currents into voltage responses without limiting the throughput of these messages. As the bumps reflected fast changes in membrane resistance, the data suggest that their shape is predominantly driven by fast changes in the light-gated conductance. On the other hand, the slower bump latency distribution is likely to represent slower enzymatic intracellular reactions. Furthermore, the Q10s of bump duration and latency distribution depended on light intensity. Altogether, this study suggests that biochemical constraints imposed upon signaling change continuously as locust photoreceptors adapt to environmental light and temperature conditions. PMID:18478123

  8. Locust bean gum: a versatile biopolymer.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Nagar, Bhanu J

    2013-05-15

    Biopolymers or natural polymers are an attractive class of biodegradable polymers since they are derived from natural sources, easily available, relatively cheap and can be modified by suitable reagent. Locust bean gum is one of them that have a wide potentiality in drug formulations due to its extensive application as food additive and its recognized lack of toxicity. It can be tailored to suit its demands of applicants in both the pharmaceutical and biomedical areas. Locust bean gum has a wide application either in the field of novel drug delivery system as rate controlling excipients or in tissue engineering as scaffold formation. Through keen references of reported literature on locust bean gum, in this review, we have described critical aspects of locust bean gum, its manufacturing process, physicochemical properties and applications in various drug delivery systems. PMID:23544637

  9. Cellularization in locust embryos occurs before blastoderm formation.

    PubMed

    Ho, K; Dunin-Borkowski, O M; Akam, M

    1997-07-01

    In Drosophila intracellular gradients establish the pattern of segmentation by controlling gene expression during a critical syncytial stage, prior to cellularization. To investigate whether a similar mechanism may be exploited by other insects, we examined the timing of cellularization with respect to blastoderm formation in an insect with extreme short-germ development, the African desert locust, Schistocerca gregaria. Using light and electron microscopic techniques, we show that the islands of cytoplasm surrounding cleavage nuclei are largely isolated from their neighbours, allowing cleavage to proceed asynchronously. Within a short time of their arrival at the surface and prior to blastoderm formation, nuclei become surrounded by complete cell membranes that block the free uptake of dye (10,000 kDa) from the yolk. Our results imply that the formation of the blastoderm disc involves the aggregation of cells at the posterior pole of the egg and not the migration of nuclei within a syncytial cytoplasm. These findings suggest that the primary cleavage syncytium does not play the same role in patterning the locust embryo as it does in Drosophila. However, we do identify a syncytial nuclear layer that underlies the forming blastoderm and remains in continuity with the yolk. PMID:9226447

  10. Bristly locust: Establishment success in an emulated organic silvopasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bristly locust (Robinia hispida) is a native tree legume found throughout much of the US, but it has received relatively little attention as a potential crop. While only 2-10 ft tall, bristly locust somewhat resembles black locust, produces pink flowers, and the stems are covered by soft, inoffensiv...

  11. Locusts for Lunch: Connecting Mathematics, Science, and Literature

    ERIC Educational Resources Information Center

    Austin, Richard A.; Thompson, Denisse R.; Beckmann, Charlene E.

    2006-01-01

    This article connects three disciplines while exploring how students computed tons of food consumed by both locusts and people. Included with this article are two worksheets "How Much Does a Locust Eat?" and "Can You Eat Those Locusts?". (Contains 3 figures.)

  12. ALLEMOTRY AND BIOMASS OF POLLARDED BLACK LOCUST

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climatic constraints can cause forage deficits in summer in west-central Arkansas, necessitating expensive, supplemental hay feeding. Black locust might be used for summer browse, but the temporal distribution of foliar biomass has not been adequately tested. Our objective was to determine effects o...

  13. The Locust Jump: An Integrated Laboratory Investigation

    ERIC Educational Resources Information Center

    Scott, Jon

    2005-01-01

    The locust is well known for its ability to jump large distances to avoid predation. This class sets out a series of investigations into the mechanisms underlying the jump enabling students to bring together information from biomechanics, muscle physiology, and anatomy. The nature of the investigation allows it to be undertaken at a number of…

  14. Diet Drives the Collective Migrations and Affects the Immunity of Mormon Crickets and Locusts: A Comparison of These Potential Superspreaders of Disease.

    PubMed

    Srygley, R B

    2016-08-01

    Differential transmission of disease among individuals within a population or among species in a community can result in superspreaders, relatively rare individuals responsible for a large proportion of transmission events. Migrating Mormon crickets and nymphal locusts readily engage in cannibalistic attacks and necrophagy. Typically multiple individuals consume a cadaver, which fosters the spread of disease. Cannibalistic attacks result in aligned, coordinated movement of individuals in massive bands that march daily for weeks at a time. Coordinated movement reduces contact frequency, which not only reduces cannibalism but the risk of disease transmission. When crowded, Mormon crickets and locusts elevate their constitutive immunity, which further reduces the risk of disease transmission. Bands of Mormon crickets show a variety of macronutrient dietary deficiencies that determine whether they will be more susceptible to pathogenic bacteria or fungi. In some migratory bands, Mormon crickets seek carbohydrates and have less anti-bacterial activity. A lipid transport protein that functions in both fuelling migration and anti-bacterial activity may cause a trade-off between the two activities when carbohydrates are limited. In other migratory bands, Mormon crickets prefer protein over carbohydrates, indicating protein-deficiency. In these bands, the generalized immunity of Mormon crickets, measured as phenoloxidase, is compromised, and the insects are more susceptible to Beauveria bassiana fungal infection. In locusts, a high protein diet resulted in greater susceptibility to another entomopathogenic fungus, Metarhizium acridum, whereas in Mormon crickets, both phenoloxidase titers and immunity to M acridum increased with adult age. Color changes associated with death by either of these fungi diminishes cannibalism, but bands may cull infected or encounter cadavers too quickly to effectively reduce fungal transmission. As long as the insects show no signs of infection

  15. Building Migratory Bridges

    ERIC Educational Resources Information Center

    Roy, Michael; Doss, Laurie K.

    2007-01-01

    The Building Migratory Bridges (BOMB) program--a collaboration between the Marvel wood School and Audubon Sharon in Connecticut and Conservation Research Education Action (CR EA), a U.S. not-for-profit in Panama--uses nontropical migratory bird research in the United States and Panama to demonstrate how negative environmental impacts in one…

  16. Phenotypic transformation affects associative learning in the desert locust.

    PubMed

    Simões, Patrício M V; Niven, Jeremy E; Ott, Swidbert R

    2013-12-01

    In desert locusts, increased population densities drive phenotypic transformation from the solitarious to the gregarious phase within a generation [1-4]. Here we show that when presented with odor-food associations, the two extreme phases differ in aversive but not appetitive associative learning, with solitarious locusts showing a conditioned aversion more quickly than gregarious locusts. The acquisition of new learned aversions was blocked entirely in acutely crowded solitarious (transiens) locusts, whereas appetitive learning and prior learned associations were unaffected. These differences in aversive learning support phase-specific feeding strategies. Associative training with hyoscyamine, a plant alkaloid found in the locusts' habitat [5, 6], elicits a phase-dependent odor preference: solitarious locusts avoid an odor associated with hyoscyamine, whereas gregarious locusts do not. Remarkably, when solitarious locusts are crowded and then reconditioned with the odor-hyoscyamine pairing as transiens, the specific blockade of aversive acquisition enables them to override their prior aversive memory with an appetitive one. Under fierce food competition, as occurs during crowding in the field, this provides a neuroecological mechanism enabling locusts to reassign an appetitive value to an odor that they learned previously to avoid. PMID:24268415

  17. A step to the gigantic genome of the desert locust: chromosome sizes and repeated DNAs.

    PubMed

    Camacho, J P M; Ruiz-Ruano, F J; Martín-Blázquez, R; López-León, M D; Cabrero, J; Lorite, P; Cabral-de-Mello, D C; Bakkali, M

    2015-06-01

    The desert locust (Schistocerca gregaria) has been used as material for numerous cytogenetic studies. Its genome size is estimated to be 8.55 Gb of DNA comprised in 11 autosomes and the X chromosome. Its X0/XX sex chromosome determinism therefore results in females having 24 chromosomes whereas males have 23. Surprisingly, little is known about the DNA content of this locust's huge chromosomes. Here, we use the Feulgen Image Analysis Densitometry and C-banding techniques to respectively estimate the DNA quantity and heterochromatin content of each chromosome. We also identify three satellite DNAs using both restriction endonucleases and next-generation sequencing. We then use fluorescent in situ hybridization to determine the chromosomal location of these satellite DNAs as well as that of six tandem repeat DNA gene families. The combination of the results obtained in this work allows distinguishing between the different chromosomes not only by size, but also by the kind of repetitive DNAs that they contain. The recent publication of the draft genome of the migratory locust (Locusta migratoria), the largest animal genome hitherto sequenced, invites for sequencing even larger genomes. S. gregaria is a pest that causes high economic losses. It is thus among the primary candidates for genome sequencing. But this species genome is about 50 % larger than that of L. migratoria, and although next-generation sequencing currently allows sequencing large genomes, sequencing it would mean a greater challenge. The chromosome sizes and markers provided here should not only help planning the sequencing project and guide the assembly but would also facilitate assigning assembled linkage groups to actual chromosomes. PMID:25472934

  18. Speed over efficiency: locusts select body temperatures that favour growth rate over efficient nutrient utilization.

    PubMed

    Miller, Gabriel A; Clissold, Fiona J; Mayntz, David; Simpson, Stephen J

    2009-10-22

    Ectotherms have evolved preferences for particular body temperatures, but the nutritional and life-history consequences of such temperature preferences are not well understood. We measured thermal preferences in Locusta migratoria (migratory locusts) and used a multi-factorial experimental design to investigate relationships between growth/development and macronutrient utilization (conversion of ingesta to body mass) as a function of temperature. A range of macronutrient intake values for insects at 26, 32 and 38 degrees C was achieved by offering individuals high-protein diets, high-carbohydrate diets or a choice between both. Locusts placed in a thermal gradient selected temperatures near 38 degrees C, maximizing rates of weight gain; however, this enhanced growth rate came at the cost of poor protein and carbohydrate utilization. Protein and carbohydrate were equally digested across temperature treatments, but once digested both macronutrients were converted to growth most efficiently at the intermediate temperature (32 degrees C). Body temperature preference thus yielded maximal growth rates at the expense of efficient nutrient utilization. PMID:19625322

  19. Pharmacology of the octopamine receptor from locust central nervous tissue (OAR3).

    PubMed Central

    Roeder, T

    1995-01-01

    1. The present study characterized highly effective agonists from different classes of compounds for the neuronal octopamine receptor (OAR3) of the migratory locust (Locusta migratoria L.). Biogenic amines and phenyliminoimidazolidines (PIIs) were employed for the study of structure-activity relationships. 2. The highest affinity PIIs were predominantly those with substitutions at the positions 2 and 4 of the phenolic ring (e.g. NC 7, KI = 0.3 nM, NC 8, KI = 0.81 nM). Substitutions at these positions always had positive effects on the affinity of the respective agonists. 3. Substitutions at the positions 3, 5 and 6, however, always had negative effects on the affinity. At the position one of the phenolic ring, heterocyclic substituents are preferred. 4. Some PIIs had a more than 30 times higher affinity for OARs than for alpha-adrenoceptors which are the vertebrate homologues of the insect octopamine receptors. 5. The only non-PII with subnanomolar affinity was the aminooxazoline derivative AC 6 (KI = 0.92 nM). 6. A variety of substances with known insecticidal activity such as chlordimeform, demethylchlor-dimeform, amitraz or AC 6 had high affinity for the locust neuronal octopamine receptor. PMID:7712020

  20. Regulation of locust fat-body phosphorylase

    PubMed Central

    Applebaum, S. W.; Schlesinger, H. M.

    1973-01-01

    1. Glycogen phosphorylase of locust fat-body was partially purified by differential centrifugation and dissociation from glycogen particles at two pH values. 2. Optimum activity was obtained at pH6.6–6.7. 3. The calculated apparent Km values for glycogen and glucose 1-phosphate were 0.08% and 10–13mm respectively. 4. 5′-AMP activated in the range 5μm–1mm. 5. Glucose 6-phosphate is a competitive inhibitor for the substrate glucose 1-phosphate (Ki=1.7mm). 5′-AMP abolishes this inhibition. Glucose weakly inhibits (Ki=25–30mm), but trehalose does not inhibit even at 100mm. 6. It is suggested that glucose 6-phosphate is a major regulator of glycogen phosphorylase activity in locust fat-body. PMID:4776873

  1. Effect of cooling rates on the cold hardiness and cryoprotectant profiles of locust eggs.

    PubMed

    Wang, Hong-Sheng; Kang, Le

    2005-10-01

    To examine the relationship between cooling rate and cold hardiness in eggs of the migratory locust, Locusta migratoria, the survival rates and cryoprotectant levels of three embryonic developmental stages were measured at different cooling rates (from 0.05 to 0.8 degrees C min(-1)) in acclimated and non-acclimated eggs. Egg survival rate increased with decreasing cooling rate. The concentration of cryoprotectants (myo-inositol, trehalose, mannitol, glycerol, and sorbitol) increased in non-acclimated eggs, but varied significantly in response to different cooling rates in acclimated eggs. The acclimation process (5 degrees C for 3 days) did not increase eggs resistance to quick cooling ("plunge" cooling and 0.8 degrees C min(-1)). Earlier stage embryos were much more sensitive than later stage embryos to the same cooling rates. Time spent at subzero temperatures also had a strong influence on egg survival. PMID:16115620

  2. [Comparative investigation of locust's phototactic visual spectrum effect and phototactic response to spectral illumination].

    PubMed

    Liu, Qi-Hang; Zhou, Qiang

    2014-07-01

    To provide theoretical support for determining locust's phototactic spectrum, and explore locust's phototactic mechanism stimulated by light, utilizing AvaSpec fiber-optic spectrometer system and AvaLight-DHS, the investigation of locust's phototactic visual spectrum effect after light energy stimulated locust's vision system was carried out and on this basis, utilizing the investigated device of locust's phototactic response to spectral illumination, the discrepancy of locust's phototactic response to spectral illumination was certificated comparatively. The results show that the degree of locust's vision system absorbing the single spectrum photon of 430, 545 and 610 nm is significant and there exists difference, and the behavioral response to orange, violet, green, and blue spectral light has the difference in selective sensitivity, with the intensity of response to violet light being the strongest. The degree of response to orange light is the maximum, simultaneously, locust's vision system absorbing spectral photon energy has selective difference and requirement of illumination time, moreover, the sensitive degree of locust's visual system to spectrum and the strength of the lighting energy, influencing locust's phototactic response degree, and the micro-response of locust's phototactic vision physiology, led by the photoelectric effect of locust absorbing sensitive photon and converting photon energy, is the reason for locust's phototactic orientation response. In addition, locust's phototactic visual spectrum effect, only when the biological photoelectric effect of locust's visual system is stimulated by spectral illumination, can present the sensitivity of the spectral absorption effect, so, using the stronger ultraviolet stimulation characteristic of violet light, the different sensitive stimulation of orange, green, blue spectral light on locust's phototactic vision, and combining orange, violet, green, blue spectral light field mechanism reasonably, can

  3. A conceptual method for monitoring locust habitat

    USGS Publications Warehouse

    Howard, Stephen M.; Loveland, Thomas R.; Ohlen, Donald O.; Moore, Donald G.; Gallo, Kevin P.; Olsson, Jonathon

    1987-01-01

    A procedure to map and monitor vegetation conditions in near-real time was developed at the United States Geological Survey;s Earth Resources Observation Systems Data Center for use in locust control efforts. Meteorological satellite dat were acquired daily for 3 weeks in October and November 1986 over a 1.4-million-square-kilometer study area centered on Botswana in southern Africa. Advanced Very High Resolution Radiometer data were screened to remove cloud-contaminated data and registered to a 1-kilometer geographic base. Each day the normalized difference vegetation index (NDVI) was calculated to determine the presence and relative amounts of green vegetation in the area. Over a 10-day cycle, subsequent dates of NDVI data were composited to fill in data removed by the cloud-screening process. At any pixel location, the maximum NDVI value was retained. At the end of the 10-day cycle, a composite vegetation-greenness map was produced and another cycle started. Greenness-change maps were produced by comparing two 10-day composite greenness images. Automated map production procedures were used to merge the NDVI image data with cartographic data (boundaries, roads, tick marks) digitized from 1:1,000,000-scale operational navigation charts. The vegetation-greenness map shoes the current distribution of vegetation in the region and can be used to locate potential locust breeding area. The change map shows areas where increases and decreases in greenness have occurred between processing cycles. Significant areas of locust damage in remote regions are characterized by an unexpected decrease in greenness. These maps can be used by locust control teams to efficiently target areas for reconnaissance. In general, the procedures and products have utility for resource managers who are required to monitor vegetation resources over large geographic regions.

  4. Locust Dynamics: Behavioral Phase Change and Swarming

    PubMed Central

    Topaz, Chad M.; D'Orsogna, Maria R.; Edelstein-Keshet, Leah; Bernoff, Andrew J.

    2012-01-01

    Locusts exhibit two interconvertible behavioral phases, solitarious and gregarious. While solitarious individuals are repelled from other locusts, gregarious insects are attracted to conspecifics and can form large aggregations such as marching hopper bands. Numerous biological experiments at the individual level have shown how crowding biases conversion towards the gregarious form. To understand the formation of marching locust hopper bands, we study phase change at the collective level, and in a quantitative framework. Specifically, we construct a partial integrodifferential equation model incorporating the interplay between phase change and spatial movement at the individual level in order to predict the dynamics of hopper band formation at the population level. Stability analysis of our model reveals conditions for an outbreak, characterized by a large scale transition to the gregarious phase. A model reduction enables quantification of the temporal dynamics of each phase, of the proportion of the population that will eventually gregarize, and of the time scale for this to occur. Numerical simulations provide descriptions of the aggregation's structure and reveal transiently traveling clumps of gregarious insects. Our predictions of aggregation and mass gregarization suggest several possible future biological experiments. PMID:22916003

  5. CRF-Like Diuretic Hormone Negatively Affects Both Feeding and Reproduction in the Desert Locust, Schistocerca gregaria

    PubMed Central

    Van Wielendaele, Pieter; Dillen, Senne; Marchal, Elisabeth; Badisco, Liesbeth; Vanden Broeck, Jozef

    2012-01-01

    Diuretic hormones (DH) related to the vertebrate Corticotropin Releasing Factor (CRF) have been identified in diverse insect species. In the migratory locust, Locusta migratoria, the CRF-like DH (CRF/DH) is localized in the same neurosecretory cells as the Ovary Maturating Parsin (OMP), a neurohormone that stimulates oocyte growth, vitellogenesis and hemolymph ecdysteroid levels in adult female locusts. In this study, we investigated whether CRF-like DH can influence feeding and reproduction in the desert locust, Schistocerca gregaria. We identified two highly similar S. gregaria CRF-like DH precursor cDNAs, each of which also encodes an OMP isoform. Alignment with other insect CRF-like DH precursors shows relatively high conservation of the CRF/DH sequence while the precursor region corresponding to OMP is not well conserved. Quantitative real-time RT-PCR revealed that the precursor transcripts mainly occur in the central nervous system and their highest expression level was observed in the brain. Injection of locust CRF/DH caused a significantly reduced food intake, while RNAi knockdown stimulated food intake. Therefore, our data indicate that CRF-like DH induces satiety. Furthermore, injection of CRF/DH in adult females retarded oocyte growth and caused lower ecdysteroid titers in hemolymph and ovaries, while RNAi knockdown resulted in opposite effects. The observed effects of CRF/DH may be part of a wider repertoire of neurohormonal activities, constituting an integrating control system that affects food intake and excretion, as well as anabolic processes like oocyte growth and ecdysteroidogenesis, following a meal. Our discussion about the functional relationship between CRF/DH and OMP led to the hypothesis that OMP may possibly act as a monitoring peptide that can elicit negative feedback effects. PMID:22363645

  6. Density-dependent aposematism in the desert locust.

    PubMed

    Sword, G A; Simpson, S J; El Hadi, O T; Wilps, H

    2000-01-01

    The ecological processes underlying locust swarm formation are poorly understood. Locust species exhibit phenotypic plasticity in numerous morphological, physiological and behavioural traits as their population density increases. These density-dependent changes are commonly assumed to be adaptations for migration under heterogeneous environmental conditions. Here we demonstrate that density-dependent nymphal colour change in the desert locust Schistocerca gregaria (Orthoptera: Acrididae) results in warning coloration (aposematism) when the population density increases and locusts consume native, toxic host plants. Fringe-toed lizards (Acanthodactylus dumerili (Lacertidae)) developed aversions to high-density-reared (gregarious-phase) locusts fed Hyoscyamus muticus (Solanaceae). Lizards associated both olfactory and visual cues with locust unpalatability, but only gregarious-phase coloration was an effective visual warning signal. The lizards did not associate low rearing density coloration (solitarious phase) with locust toxicity. Predator learning of density-dependent warning coloration results in a marked decrease in predation on locusts and may directly contribute to outbreaks of this notorious pest. PMID:10670954

  7. Phenotypic Transformation Affects Associative Learning in the Desert Locust

    PubMed Central

    Simões, Patrício M.V.; Niven, Jeremy E.; Ott, Swidbert R.

    2013-01-01

    Summary In desert locusts, increased population densities drive phenotypic transformation from the solitarious to the gregarious phase within a generation [1–4]. Here we show that when presented with odor-food associations, the two extreme phases differ in aversive but not appetitive associative learning, with solitarious locusts showing a conditioned aversion more quickly than gregarious locusts. The acquisition of new learned aversions was blocked entirely in acutely crowded solitarious (transiens) locusts, whereas appetitive learning and prior learned associations were unaffected. These differences in aversive learning support phase-specific feeding strategies. Associative training with hyoscyamine, a plant alkaloid found in the locusts’ habitat [5, 6], elicits a phase-dependent odor preference: solitarious locusts avoid an odor associated with hyoscyamine, whereas gregarious locusts do not. Remarkably, when solitarious locusts are crowded and then reconditioned with the odor-hyoscyamine pairing as transiens, the specific blockade of aversive acquisition enables them to override their prior aversive memory with an appetitive one. Under fierce food competition, as occurs during crowding in the field, this provides a neuroecological mechanism enabling locusts to reassign an appetitive value to an odor that they learned previously to avoid. PMID:24268415

  8. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  9. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  10. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  11. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  12. 21 CFR 582.7343 - Locust bean gum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Locust bean gum. 582.7343 Section 582.7343 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... bean gum. (a) Product. Locust (carob) bean gum. (b) Conditions of use. This substance is...

  13. A Locust Cage and Hatchery from Plastic Aquarium Tanks

    ERIC Educational Resources Information Center

    Stoneman, C. F.; And Others

    1973-01-01

    Describes how to construct a locust cage from two plastic aquaria and four coffee jars with plastic lids. Its advantages over a conventional locust cage include the inexpensive cost, lack of breakable glass, ease of cleaning, and visibility from all angles. (JR)

  14. miR-71 and miR-263 Jointly Regulate Target Genes Chitin synthase and Chitinase to Control Locust Molting.

    PubMed

    Yang, Meiling; Wang, Yanli; Jiang, Feng; Song, Tianqi; Wang, Huimin; Liu, Qing; Zhang, Jie; Zhang, Jianzhen; Kang, Le

    2016-08-01

    Chitin synthase and chitinase play crucial roles in chitin biosynthesis and degradation during insect molting. Silencing of Dicer-1 results in reduced levels of mature miRNAs and severely blocks molting in the migratory locust. However, the regulatory mechanism of miRNAs in the molting process of locusts has remained elusive. In this study, we found that in chitin metabolism, two crucial enzymes, chitin synthase (CHS) and chitinase (CHT) were regulated by miR-71 and miR-263 during nymph molting. The coding sequence of CHS1 and the 3'-untranslated region of CHT10 contain functional binding sites for miR-71 and miR-263, respectively. miR-71/miR-263 displayed cellular co-localization with their target genes in epidermal cells and directly interacted with CHS1 and CHT10 in the locust integument, respectively. Injections of miR-71 and miR-263 agomirs suppressed the expression of CHS1 and CHT10, which consequently altered chitin production of new and old cuticles and resulted in a molting-defective phenotype in locusts. Unexpectedly, reduced expression of miR-71 and miR-263 increased CHS1 and CHT10 mRNA expression and led to molting defects similar to those induced by miRNA delivery. This study reveals a novel function and balancing modulation pattern of two miRNAs in chitin biosynthesis and degradation, and it provides insight into the underlying molecular mechanisms of the molting process in locusts. PMID:27532544

  15. miR-71 and miR-263 Jointly Regulate Target Genes Chitin synthase and Chitinase to Control Locust Molting

    PubMed Central

    Jiang, Feng; Song, Tianqi; Wang, Huimin; Liu, Qing; Zhang, Jie; Zhang, Jianzhen; Kang, Le

    2016-01-01

    Chitin synthase and chitinase play crucial roles in chitin biosynthesis and degradation during insect molting. Silencing of Dicer-1 results in reduced levels of mature miRNAs and severely blocks molting in the migratory locust. However, the regulatory mechanism of miRNAs in the molting process of locusts has remained elusive. In this study, we found that in chitin metabolism, two crucial enzymes, chitin synthase (CHS) and chitinase (CHT) were regulated by miR-71 and miR-263 during nymph molting. The coding sequence of CHS1 and the 3’-untranslated region of CHT10 contain functional binding sites for miR-71 and miR-263, respectively. miR-71/miR-263 displayed cellular co-localization with their target genes in epidermal cells and directly interacted with CHS1 and CHT10 in the locust integument, respectively. Injections of miR-71 and miR-263 agomirs suppressed the expression of CHS1 and CHT10, which consequently altered chitin production of new and old cuticles and resulted in a molting-defective phenotype in locusts. Unexpectedly, reduced expression of miR-71 and miR-263 increased CHS1 and CHT10 mRNA expression and led to molting defects similar to those induced by miRNA delivery. This study reveals a novel function and balancing modulation pattern of two miRNAs in chitin biosynthesis and degradation, and it provides insight into the underlying molecular mechanisms of the molting process in locusts. PMID:27532544

  16. Biomechanical and dynamic mechanism of locust take-off

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Sheng; Yin, Jun-Mao; Chen, Ke-Wei; Li, Zhen

    2014-10-01

    The biomimetic locust robot hopping vehicle has promising applications in planet exploration and reconnaissance. This paper explores the bionic dynamics model of locust jumping by using high-speed video and force analysis. This paper applies hybrid rigid-flexible mechanisms to bionic locust hopping and studies its dynamics with emphasis laid on the relationship between force and jumping performance. The hybrid rigid-flexible model is introduced in the analysis of locust mechanism to address the principles of dynamics that govern locust joints and mechanisms during energy storage and take-off. The dynamic response of the biomimetic mechanism is studied by considering the flexibility according to the locust jumping dynamics mechanism. A multi-rigid-body dynamics model of locust jumping is established and analyzed based on Lagrange method; elastic knee and tarsus mechanisms that were proposed in previous works are analyzed alongside the original bionic joint configurations and their machinery principles. This work offers primary theories for take-off dynamics and establishes a theoretical basis for future studies and engineering applications.

  17. A locust-inspired miniature jumping robot.

    PubMed

    Zaitsev, Valentin; Gvirsman, Omer; Ben Hanan, Uri; Weiss, Avi; Ayali, Amir; Kosa, Gabor

    2015-12-01

    Unmanned ground vehicles are mostly wheeled, tracked, or legged. These locomotion mechanisms have a limited ability to traverse rough terrain and obstacles that are higher than the robot's center of mass. In order to improve the mobility of small robots it is necessary to expand the variety of their motion gaits. Jumping is one of nature's solutions to the challenge of mobility in difficult terrain. The desert locust is the model for the presented bio-inspired design of a jumping mechanism for a small mobile robot. The basic mechanism is similar to that of the semilunar process in the hind legs of the locust, and is based on the cocking of a torsional spring by wrapping a tendon-like wire around the shaft of a miniature motor. In this study we present the jumping mechanism design, and the manufacturing and performance analysis of two demonstrator prototypes. The most advanced jumping robot demonstrator is power autonomous, weighs 23 gr, and is capable of jumping to a height of 3.35 m, covering a distance of 1.37 m. PMID:26602094

  18. Neuromechanical simulation of the locust jump.

    PubMed

    Cofer, D; Cymbalyuk, G; Heitler, W J; Edwards, D H

    2010-04-01

    The neural circuitry and biomechanics of kicking in locusts have been studied to understand their roles in the control of both kicking and jumping. It has been hypothesized that the same neural circuit and biomechanics governed both behaviors but this hypothesis was not testable with current technology. We built a neuromechanical model to test this and to gain a better understanding of the role of the semi-lunar process (SLP) in jump dynamics. The jumping and kicking behaviors of the model were tested by comparing them with a variety of published data, and were found to reproduce the results from live animals. This confirmed that the kick neural circuitry can produce the jump behavior. The SLP is a set of highly sclerotized bands of cuticle that can be bent to store energy for use during kicking and jumping. It has not been possible to directly test the effects of the SLP on jump performance because it is an integral part of the joint, and attempts to remove its influence prevent the locust from being able to jump. Simulations demonstrated that the SLP can significantly increase jump distance, power, total energy and duration of the jump impulse. In addition, the geometry of the joint enables the SLP force to assist leg flexion when the leg is flexed, and to assist extension once the leg has begun to extend. PMID:20228342

  19. Acanthamoeba produces disseminated infection in locusts and traverses the locust blood-brain barrier to invade the central nervous system

    PubMed Central

    2010-01-01

    Background Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS). Results Using Acanthamoeba isolates belonging to the T1 and T4 genotypes, the findings revealed that amoebae induced sickness behaviour in locusts, as evidenced by reduced faecal output and weight loss and, eventually, leading to 100% mortality. Significant degenerative changes of various tissues were observed by histological sectioning. Both isolates produced disseminated infection, with viable amoebae being recovered from various tissues. Histological examination of the CNS showed that Acanthamoeba invaded the locust CNS, and this is associated with disruption of the perineurium cell/glial cell complex, which constitutes the locust blood-brain barrier. Conclusions This is the first study to demonstrate that Acanthamoeba invades locust brain by modulating the integrity of the insect's blood-brain barrier, a finding that is consistent with the human infection. These observations support the idea that locusts provide a tractable model to study Acanthamoeba encephalitis in vivo. In this way the locust model may generate potentially useful leads that can be tested subsequently in mammalian systems, thus replacing the use of vertebrates at an early stage, and reducing the numbers of mammals required overall. PMID:20615207

  20. The contribution of the genomes of a termite and a locust to our understanding of insect neuropeptides and neurohormones

    PubMed Central

    Veenstra, Jan A.

    2014-01-01

    The genomes of the migratory locust Locusta migratoria and the termite Zootermopsis nevadensis were mined for the presence of genes encoding neuropeptides, neurohormones, and their G-protein coupled receptors (GPCRs). Both species have retained a larger number of neuropeptide and neuropeptide GPCRs than the better known holometabolous insect species, while other genes that in holometabolous species appear to have a single transcript produce two different precursors in the locust, the termite or both. Thus, the recently discovered CNMa neuropeptide gene has two transcripts predicted to produce two structurally different CNMa peptides in the termite, while the locust produces two different myosuppressin peptides in the same fashion. Both these species also have a calcitonin gene, which is different from the gene encoding the calcitonin-like insect diuretic hormone. This gene produces two types of calcitonins, calcitonins A and B. It is also present in Lepidoptera and Coleoptera and some Diptera, but absent from mosquitoes and Drosophila. However, in holometabolous insect species, only the B transcript is produced. Their putative receptors were also identified. In contrast, Locusta has a highly unusual gene that codes for a salivation stimulatory peptide. The Locusta genes for neuroparsin and vasopressin are particularly interesting. The neuroparsin gene produces five different transcripts, of which only one codes for the neurohormone identified from the corpora cardiaca. The other four transcripts code for neuroparsin-like proteins, which lack four amino acid residues, and that for that reason we called neoneuroparsins. The number of transcripts for the neoneuroparsins is about 200 times larger than the number of neuroparsin transcripts. The first exon and the putative promoter of the vasopressin genes, of which there are about seven copies in the genome, is very well-conserved, but the remainder of these genes is not. The relevance of these findings is discussed

  1. Motion detectors in the locust visual system: From biology to robot sensors.

    PubMed

    Rind, F Claire

    2002-02-15

    Motion detectors in the locust optic lobe and brain fall into two categories: neurones that respond selectively to approaching vs. receding objects and neurones that respond selectively to a particular pattern of image motion over a substantial part of the eye, generated by the locust's own movements through its environment. Neurones from the two categories can be differentiated on the basis of their response to motion at a constant velocity at a fixed distance from the locust: neurones of the first category respond equally well to motion in any direction whereas neurones in the second category respond selectively to one preferred direction of motion. Several of the motion detectors of the first category, responding to approaching objects, share the same input organisation, suggesting that it is important in generating a tuning for approaching objects. Anatomical, physiological, and modelling studies have revealed how the selectivity of the response is generated. The selectivity arises as a result of a critical race between excitation, generated when image edges move out over the eye and delayed inhibition, generated by the same edge movements. For excitation to build up, the velocity and extent of edge motion over the eye must increase rapidly. The ultrastructure of the afferent inputs onto the dendrites of collision sensitive neurones reveals a possible substrate for the interaction between excitation and inhibition. This interpretation is supported by both physiological and immunocytochemical evidence. The input organisation of these neurones has been incorporated into the control structure of a small mobile robot, which successfully avoids collisions with looming objects. The ecological role of motion detectors of the second category that respond to image motion over a substantial part of the visual field, is discussed as is the input organisation that generates this selective response. The broad tuning of these neurones, particularly at low velocities (<0

  2. Morphology and design of the extensible intersegmental membrane of the female migratory locust.

    PubMed

    Vincent, J F

    1981-01-01

    The morphology of the extensible intersegmental membrane (i.s.m.) of the female Locusta migratoria migratorioides is dictated by three main requirements: (a) high extensibility (1500%), (b) low stiffness (5 X 10(3) Pa), (c) low Poisson ratio in the plane of the cuticle (0.01 or less). These requirements can be met only orientating the chitin orthogonally to the direction of extension and having the protein phase uncross-linked and of very low modulus. The Poisson ratio requirement also implies that for the material to be extended at constant volume extreme thinning must occur during extension, giving rise to high shear strains in the direction of extension. The ultrastructure and morphological elements are modified from 'normal' cuticle such as to provide for high extensibility (due to unfolding) of the epicuticle and epidermal cells and a complex system of intracuticular fibres which are probably necessary to retain the topology of the components during high shear straining. No new morphological elements are adduced in this study but the extreme adaptability of those established for other cuticles is illustrated. PMID:7330860

  3. Heterologous expression and characterization of two chitinase 5 enzymes from the migratory locust Locusta migratoria.

    PubMed

    Li, Ying-Long; Song, Hui-Fang; Zhang, Xue-Yao; Li, Da-Qi; Zhang, Ting-Ting; Ma, En-Bo; Zhang, Jian-Zhen

    2016-06-01

    Insect chitinases are involved in degradation of chitin from the exoskeleton or peritrophic metrix of midgut. In Locusta migratoria, two duplicated Cht5s (LmCht5-1 and LmCht5-2) have been shown to have distinct molecular characteristics and biological roles. To explore the protein properties of the two LmCht5s, we heterologously expressed both enzymes using baculovirus expression system in SF9 cells, and characterized kinetic and carbohydrate-binding properties of purified enzymes. LmCht5-1 and LmCht5-2 exhibited similar pH and temperature optimums. LmCht5-1 has lower Km value for the oligomeric substrate (4MU-(GlcNAc)3 ), and higher Km value for the longer substrate (CM-Chitin-RBV) compared with LmCht5-2. A comparison of amino acids and homology modeling of catalytic domain presented similar TIM barrel structures and differentiated amino acids between two proteins. LmCht5-1 has a chitin-binding domain (CBD) tightly bound to colloidal chitin, but LmCht5-2 does not have a CBD for binding to colloidal chitin. Our results suggested both LmCht5-1 and LmCht5-2, which have the critical glutamate residue in region II of catalytic domain, exhibited chitinolytic activity cleaving both polymeric and oligomeric substrates. LmCht5-1 had relatively higher activity against the oligomeric substrate, 4MU-(GlcNAc)3 , whereas LmCht5-2 exhibited higher activity toward the longer substrate, CM-Chitin-RBV. These findings are helpful for further research to clarify their different roles in insect growth and development. PMID:26792119

  4. Sulfakinin is an important regulator of digestive processes in the migratory locust, Locusta migratoria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sulfakinin (SK) is a sulfated insect neuropeptide that is best known for its function as a satiety factor. It displays structural and functional similarities with the vertebrate peptides gastrin and cholecystokinin. Peptidomic studies in multiple insects, crustaceans and arachnids have revealed th...

  5. Optimal Conservation of Migratory Species

    PubMed Central

    Martin, Tara G.; Chadès, Iadine; Arcese, Peter; Marra, Peter P.; Possingham, Hugh P.; Norris, D. Ryan

    2007-01-01

    Background Migratory animals comprise a significant portion of biodiversity worldwide with annual investment for their conservation exceeding several billion dollars. Designing effective conservation plans presents enormous challenges. Migratory species are influenced by multiple events across land and sea–regions that are often separated by thousands of kilometres and span international borders. To date, conservation strategies for migratory species fail to take into account how migratory animals are spatially connected between different periods of the annual cycle (i.e. migratory connectivity) bringing into question the utility and efficiency of current conservation efforts. Methodology/Principal Findings Here, we report the first framework for determining an optimal conservation strategy for a migratory species. Employing a decision theoretic approach using dynamic optimization, we address the problem of how to allocate resources for habitat conservation for a Neotropical-Nearctic migratory bird, the American redstart Setophaga ruticilla, whose winter habitat is under threat. Our first conservation strategy used the acquisition of winter habitat based on land cost, relative bird density, and the rate of habitat loss to maximize the abundance of birds on the wintering grounds. Our second strategy maximized bird abundance across the entire range of the species by adding the constraint of maintaining a minimum percentage of birds within each breeding region in North America using information on migratory connectivity as estimated from stable-hydrogen isotopes in feathers. We show that failure to take into account migratory connectivity may doom some regional populations to extinction, whereas including information on migratory connectivity results in the protection of the species across its entire range. Conclusions/Significance We demonstrate that conservation strategies for migratory animals depend critically upon two factors: knowledge of migratory

  6. Hearing ability decreases in ageing locusts.

    PubMed

    Gordon, Shira D; Windmill, James F C

    2015-07-01

    Insects display signs of ageing, despite their short lifespan. However, the limited studies on senescence emphasize longevity or reproduction. We focused on the hearing ability of ageing adult locusts, Schistocerca gregaria. Our results indicate that the youngest adults (2 weeks post-maturity) have a greater overall neurophysiological response to sound, especially for low frequencies (<10 kHz), as well as a shorter latency to this neural response. Interestingly, when measuring displacement of the tympanal membrane that the receptor neurons directly attach to, we found movement is not directly correlated with neural response. Therefore, we suggest the enhanced response in younger animals is due to the condition of their tissues (e.g. elasticity). Secondly, we found the sexes do not have the same responses, particularly at 4 weeks post-adult moult. We propose female reproductive condition reduces their ability to receive sounds. Overall our results indicate older animals, especially females, are less sensitive to sounds. PMID:25944922

  7. Dopaminergic modulation of phase reversal in desert locusts.

    PubMed

    Alessi, Ahmad M; O'Connor, Vincent; Aonuma, Hitoshi; Newland, Philip L

    2014-01-01

    Phenotypic plasticity allows animals to modify their behavior, physiology, and morphology to adapt to environmental change. The global pest, the desert locust, shows two extreme phenotypes; a solitarious phase that is relatively harmless and a gregarious phase that forms swarms and causes extensive agricultural and economic damage. In the field, environmental conditions can drive isolated animals into crowded populations and previous studies have identified the biogenic amine serotonin as a key determinant of this transition. Here we take an integrated approach to investigate the neurochemical, physiological, and behavioral correlates defined by a laboratory based paradigm that mimics facets of swarm break down as gregarious locusts become isolated. Following isolation there was an increased propensity of locusts to avoid conspecifics, and show a reduced locomotion. Changes in choice behavior occurred within 1 h of isolation although isolation-related changes progressed with increased isolation time. Isolation was accompanied by changes in the levels of the biogenic amines dopamine, octopamine, and serotonin within the CNS within 1 h. Dopamine levels were higher in isolated animals and we focused on the role played by this transmitter in synaptic changes that may underpin solitarization. Dopamine reduced synaptic efficacy at a key central synapse between campaniform sensilla (CS) and a fast extensor tibiae motor neuron that is involved in limb movement. We also show that dopamine injection into the haemocoel was sufficient to induce solitarious-like behavior in otherwise gregarious locusts. Further, injection of a dopamine antagonist, fluphenazine, into isolated locusts induced gregarious-like behavior. This highlights that dopaminergic modulation plays an important role in the plasticity underpinning phase transition and sets a context to deepen the understanding of the complementary role that distinct neuromodulators play in polyphenism in locusts. PMID:25426037

  8. Dopaminergic modulation of phase reversal in desert locusts

    PubMed Central

    Alessi, Ahmad M.; O'Connor, Vincent; Aonuma, Hitoshi; Newland, Philip L.

    2014-01-01

    Phenotypic plasticity allows animals to modify their behavior, physiology, and morphology to adapt to environmental change. The global pest, the desert locust, shows two extreme phenotypes; a solitarious phase that is relatively harmless and a gregarious phase that forms swarms and causes extensive agricultural and economic damage. In the field, environmental conditions can drive isolated animals into crowded populations and previous studies have identified the biogenic amine serotonin as a key determinant of this transition. Here we take an integrated approach to investigate the neurochemical, physiological, and behavioral correlates defined by a laboratory based paradigm that mimics facets of swarm break down as gregarious locusts become isolated. Following isolation there was an increased propensity of locusts to avoid conspecifics, and show a reduced locomotion. Changes in choice behavior occurred within 1 h of isolation although isolation-related changes progressed with increased isolation time. Isolation was accompanied by changes in the levels of the biogenic amines dopamine, octopamine, and serotonin within the CNS within 1 h. Dopamine levels were higher in isolated animals and we focused on the role played by this transmitter in synaptic changes that may underpin solitarization. Dopamine reduced synaptic efficacy at a key central synapse between campaniform sensilla (CS) and a fast extensor tibiae motor neuron that is involved in limb movement. We also show that dopamine injection into the haemocoel was sufficient to induce solitarious-like behavior in otherwise gregarious locusts. Further, injection of a dopamine antagonist, fluphenazine, into isolated locusts induced gregarious-like behavior. This highlights that dopaminergic modulation plays an important role in the plasticity underpinning phase transition and sets a context to deepen the understanding of the complementary role that distinct neuromodulators play in polyphenism in locusts. PMID:25426037

  9. Energy localization and frequency analysis in the locust ear

    PubMed Central

    Malkin, Robert; McDonagh, Thomas R.; Mhatre, Natasha; Scott, Thomas S.; Robert, Daniel

    2014-01-01

    Animal ears are exquisitely adapted to capture sound energy and perform signal analysis. Studying the ear of the locust, we show how frequency signal analysis can be performed solely by using the structural features of the tympanum. Incident sound waves generate mechanical vibrational waves that travel across the tympanum. These waves shoal in a tsunami-like fashion, resulting in energy localization that focuses vibrations onto the mechanosensory neurons in a frequency-dependent manner. Using finite element analysis, we demonstrate that two mechanical properties of the locust tympanum, distributed thickness and tension, are necessary and sufficient to generate frequency-dependent energy localization. PMID:24196693

  10. A test of the oxidative damage hypothesis for discontinuous gas exchange in the locust Locusta migratoria.

    PubMed

    Matthews, Philip G D; Snelling, Edward P; Seymour, Roger S; White, Craig R

    2012-08-23

    The discontinuous gas exchange cycle (DGC) is a breathing pattern displayed by many insects, characterized by periodic breath-holding and intermittently low tracheal O(2) levels. It has been hypothesized that the adaptive value of DGCs is to reduce oxidative damage, with low tracheal O(2) partial pressures (PO(2) ≈ 2-5 kPa) occurring to reduce the production of oxygen free radicals. If this is so, insects displaying DGCs should continue to actively defend a low tracheal PO(2) even when breathing higher than atmospheric levels of oxygen (hyperoxia). This behaviour has been observed in moth pupae exposed to ambient PO(2) up to 50 kPa. To test this observation in adult insects, we implanted fibre-optic oxygen optodes within the tracheal systems of adult migratory locusts Locusta migratoria exposed to normoxia, hypoxia and hyperoxia. In normoxic and hypoxic atmospheres, the minimum tracheal PO(2) that occurred during DGCs varied between 3.4 and 1.2 kPa. In hyperoxia up to 40.5 kPa, the minimum tracheal PO(2) achieved during a DGC exceeded 30 kPa, increasing with ambient levels. These results are consistent with a respiratory control mechanism that functions to satisfy O(2) requirements by maintaining PO(2) above a critical level, not defend against high levels of O(2). PMID:22491761

  11. Cellulolytic activity and structure of symbiotic bacteria in locust guts.

    PubMed

    Su, L-J; Liu, H; Li, Y; Zhang, H-F; Chen, M; Gao, X-H; Wang, F-Q; Song, A-D

    2014-01-01

    Locusts are able to digest the cellulose of Gramineae plants, resulting in their being considered as major crop pests. To illustrate the mechanism involved in cellulose digestion, the cellulolytic activity and zymography in the gut contents of 16 locust species were determined using carboxymethyl cellulose (CMC) as substrate. The diversity of gut symbiotic bacteria was studied using denaturing gradient gel electrophoresis (DGGE). The results showed that high CMC activity was present in Acrididae gut fluid (mean 356.4 U/g proteins). Of the 5 locust species, Oxya chinensis had the highest diversity of intestinal symbiotic bacteria, characterized by the DGGE profile containing more than 20 bands of 16S rRNA. Klebsiella pneumoniae, in the gut of Locusta migratoria manilensis, was identified as the most abundant symbiotic bacterium by DNA sequencing, with a relative abundance of 19.74%. In comparison, Methylobacterium sp was the most dominant species in the Atractomorpha sinensis gut, with a relative abundance of 29.04%. The results indicated that the cellulolytic enzymes and gut microbial communities probably reflected their phylogenetic relationship with different locust species and associated feeding strategies. PMID:25299108

  12. Ecosystem carbon exchange in response to locust outbreaks in a temperate steppe.

    PubMed

    Song, Jian; Wu, Dandan; Shao, Pengshuai; Hui, Dafeng; Wan, Shiqiang

    2015-06-01

    It is predicted that locust outbreaks will occur more frequently under future climate change scenarios, with consequent effects on ecological goods and services. A field manipulative experiment was conducted to examine the responses of gross ecosystem productivity (GEP), net ecosystem carbon dioxide (CO2) exchange (NEE), ecosystem respiration (ER), and soil respiration (SR) to locust outbreaks in a temperate steppe of northern China from 2010 to 2011. Two processes related to locust outbreaks, natural locust feeding and carcass deposition, were mimicked by clipping 80 % of aboveground biomass and adding locust carcasses, respectively. Ecosystem carbon (C) exchange (i.e., GEP, NEE, ER, and SR) was suppressed by locust feeding in 2010, but stimulated by locust carcass deposition in both years (except SR in 2011). Experimental locust outbreaks (i.e., clipping plus locust carcass addition) decreased GEP and NEE in 2010 whereas they increased GEP, NEE, and ER in 2011, leading to neutral changes in GEP, NEE, and SR across the 2 years. The responses of ecosystem C exchange could have been due to the changes in soil ammonium nitrogen, community cover, and aboveground net primary productivity. Our findings of the transient and neutral changes in ecosystem C cycling under locust outbreaks highlight the importance of resistance, resilience, and stability of the temperate steppe in maintaining reliable ecosystem services, and facilitate the projections of ecosystem functioning in response to natural disturbance and climate change. PMID:25663332

  13. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation

    PubMed Central

    Cissé, S.; Ghaout, S.; Babah Ebbe, M. A; Kamara, S; Piou, C.

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate. PMID:27432351

  14. Field Verification of the Prediction Model on Desert Locust Adult Phase Status From Density and Vegetation.

    PubMed

    Cissé, S; Ghaout, S; Babah Ebbe, M A; Kamara, S; Piou, C

    2016-01-01

    Previous studies investigated the effect of vegetation on density thresholds of adult Desert Locust gregarization from historical data in Mauritania. We examine here the prediction of locust phase based on adult density and vegetation conditions using the statistical model from Cisse et al. compared with actual behavior of Desert Locust adults observed in the field in Mauritania. From the 130 sites where adult locusts were found, the model predicted the phase of Desert Locust adults with a relatively small error of prediction of 6.1%. Preventive locust control should be rational, based on a risk assessment. The staff involved in implementation of the preventive control strategy needs specific indicators for when or where chemical treatment should be done. In this respect, we show here that the statistical model of Cisse et al. may be appropriate. PMID:27432351

  15. The FAO/NASA/NLR Artemis system - An integrated concept for environmental monitoring by satellite in support of food/feed security and desert locust surveillance

    NASA Technical Reports Server (NTRS)

    Hielkema, J. U.; Howard, J. A.; Tucker, C. J.; Van Ingen Schenau, H. A.

    1987-01-01

    The African real time environmental monitoring using imaging satellites (Artemis) system, which should monitor precipitation and vegetation conditions on a continental scale, is presented. The hardware and software characteristics of the system are illustrated and the Artemis databases are outlined. Plans for the system include the use of hourly digital Meteosat data and daily NOAA/AVHRR data to study environmental conditions. Planned mapping activities include monthly rainfall anomaly maps, normalized difference vegetation index maps for ten day and monthly periods with a spatial resolution of 7.6 km, ten day crop/rangeland moisture availability maps, and desert locust potential breeding activity factor maps for a plague prevention program.

  16. Locust adipokinetic hormones: carrier-independent transport and differential inactivation at physiological concentrations during rest and flight.

    PubMed Central

    Oudejans, R C; Vroemen, S F; Jansen, R F; Van der Horst, D J

    1996-01-01

    Since concomitant release of structurally related peptide hormones with apparently similar functions seems to be a general concept in endocrinology, we have studied the dynamics of the lifetime of the three known adipokinetic hormones (AKHs) of the migratory locust, which control flight-directed mobilization of carbohydrate and lipid from fat body stores. Although the structure of the first member of the AKHs has been known for 20 years, until now, reliable data on their inactivation and removal from the hemolymph are lacking, because measurement requires AKHs with high specific radioactivity. Employing tritiated AKHs with high specific radioactivity, obtained by catalytic reduction with tritium gas of the dehydroLeu2 analogues of the AKHs synthesized by the solid-phase procedure, studies with physiological doses of as low as 1.0 pmol per locust could be conducted. The AKHs appear to be transported in the hemolymph in their free forms and not associated with a carrier protein, despite their strong hydrophobicity. Application of AKHs in their free form in in vivo and in vitro studies therefore now has been justified. We have studied the degradation of the three AKHs during rest and flight. The first cleavage step by an endopeptidase is crucial, since the resulting degradation products lack any adipokinetic activity. Half-lives for AKH-I, -II and -III were 51, 40, and 5 min, respectively, for rest conditions and 35, 37, and 3 min, respectively, during flight. The rapid and differential degradation of structurally related hormones leads to changes in the ratio in which they are released and therefore will have important consequences for concerted hormone action at the level of the target organ or organs, suggesting that each of the known AKHs may play its own biological role in the overall syndrome of insect flight. PMID:8710926

  17. Locust adipokinetic hormones: carrier-independent transport and differential inactivation at physiological concentrations during rest and flight.

    PubMed

    Oudejans, R C; Vroemen, S F; Jansen, R F; Van der Horst, D J

    1996-08-01

    Since concomitant release of structurally related peptide hormones with apparently similar functions seems to be a general concept in endocrinology, we have studied the dynamics of the lifetime of the three known adipokinetic hormones (AKHs) of the migratory locust, which control flight-directed mobilization of carbohydrate and lipid from fat body stores. Although the structure of the first member of the AKHs has been known for 20 years, until now, reliable data on their inactivation and removal from the hemolymph are lacking, because measurement requires AKHs with high specific radioactivity. Employing tritiated AKHs with high specific radioactivity, obtained by catalytic reduction with tritium gas of the dehydroLeu2 analogues of the AKHs synthesized by the solid-phase procedure, studies with physiological doses of as low as 1.0 pmol per locust could be conducted. The AKHs appear to be transported in the hemolymph in their free forms and not associated with a carrier protein, despite their strong hydrophobicity. Application of AKHs in their free form in in vivo and in vitro studies therefore now has been justified. We have studied the degradation of the three AKHs during rest and flight. The first cleavage step by an endopeptidase is crucial, since the resulting degradation products lack any adipokinetic activity. Half-lives for AKH-I, -II and -III were 51, 40, and 5 min, respectively, for rest conditions and 35, 37, and 3 min, respectively, during flight. The rapid and differential degradation of structurally related hormones leads to changes in the ratio in which they are released and therefore will have important consequences for concerted hormone action at the level of the target organ or organs, suggesting that each of the known AKHs may play its own biological role in the overall syndrome of insect flight. PMID:8710926

  18. Locust bean gum: Exploring its potential for biopharmaceutical applications

    PubMed Central

    Dionísio, Marita; Grenha, Ana

    2012-01-01

    Polysaccharides have been finding, in the last decades, very interesting and useful applications in the biomedical and, specifically, in the biopharmaceutical field. Locust bean gum is a polysaccharide belonging to the group of galactomannans, being extracted from the seeds of the carob tree (Ceratonia siliqua). This polymer displays a number of appealing characteristics for biopharmaceutical applications, among which its high gelling capacity should be highlighted. In this review, we describe critical aspects of locust bean gum, contributing for its role in biopharmaceutical applications. Physicochemical properties, as well as strong and effective synergies with other biomaterials are described. The potential for in vivo biodegradation is explored and the specific biopharmaceutical applications are discussed. PMID:22923958

  19. Retinally-generated saccadic suppression of a locust looming-detector neuron: investigations using a robot locust.

    PubMed Central

    Santer, R. D.; Stafford, R.; Rind, F. C.

    2004-01-01

    A fundamental task performed by many visual systems is to distinguish apparent motion caused by eye movements from real motion occurring within the environment. During saccadic eye movements, this task is achieved by inhibitory signals of central and retinal origin that suppress the output of motion-detecting neurons. To investigate the retinally-generated component of this suppression, we used a computational model of a locust looming-detecting pathway that experiences saccadic suppression. This model received input from the camera of a mobile robot that performed simple saccade-like movements, allowing the model's response to simplified real stimuli to be tested. Retinally-generated saccadic suppression resulted from two inhibitory mechanisms within the looming-detector's input architecture. One mechanism fed inhibition forward through the network, inhibiting the looming-detector's initial response to movement. The second spread inhibition laterally within the network, suppressing the looming-detector's maintained response to movement. These mechanisms prevent a looming-detector model response to whole-field visual stimuli. In the locust, this mechanism of saccadic suppression may operate in addition to centrally-generated suppression. Because lateral inhibition is a common feature of early visual processing in many organisms, we discuss whether the mechanism of retinally-generated saccadic suppression found in the locust looming-detector model may also operate in these species. PMID:16849153

  20. Susceptibility to experimental infection of the invertebrate locusts (Schistocerca gregaria) with the apicomplexan parasite Neospora caninum

    PubMed Central

    Alkurashi, Mamdowh M.; May, Sean T.; Kong, Kenny; Bacardit, Jaume; Haig, David

    2014-01-01

    Neuropathogenesis is a feature of Neospora caninum infection. In order to explore this in the absence of acquired host immunity to the parasite, we have tested infection in locusts (Schistocerca gregaria). We show for the first time that locusts are permissive to intra-hemocoel infection with N. caninum tachyzoites. This was characterized by alteration in body weight, fecal output, hemoparasitemia, and sickness-related behavior. Infected locusts exhibited progressive signs of sickness leading to mortality. Also, N. caninum showed neuropathogenic affinity, induced histological changes in the brain and was able to replicate in the brain of infected locusts. Fatty acid (FA) profiling analysis of the brains by gas chromatography and multi-variate prediction models discriminated with high accuracy (98%) between the FA profiles of the infected and control locusts. DNA microarray gene expression profiling distinguished infected from control S. gregaria brain tissues on the basis of distinct differentially-expressed genes. These data indicate that locusts are permissible to infection with N. caninum and that the parasite retains its tropism for neural tissues in the invertebrate host. Locusts may facilitate preclinical testing of interventional strategies to inhibit the growth of N. caninum tachyzoites. Further studies on how N. caninum brings about changes in locust brain tissue are now warranted. PMID:25493211

  1. Survival of bristly locust (Robinia hispida) in an emulated organic silvopasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bristly locust is a native tree legume with an extensive range throughout much of the eastern US and Canada. Bristly locust is about 3 m tall, produces pink flowers, and the branches, petioles, flower stalks, and fruits are covered by soft, inoffensive bristles. Little agronomic research has been co...

  2. Survival of bristly locust (Robinia hispida L.) in an emulated organic silvopasture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bristly locust (Robinia hispida L.), a native tree legume which has received relatively little scientific attention from an agronomic perspective, could have value as livestock browse. The objective of this research was to assess transplant survival of bristly locust in an experimental silvopasture...

  3. Motor neurone responses during a postural reflex in solitarious and gregarious desert locusts.

    PubMed

    Blackburn, Laura M; Ott, Swidbert R; Matheson, Tom; Burrows, Malcolm; Rogers, Stephen M

    2010-08-01

    Desert locusts show extreme phenotypic plasticity and can change reversibly between two phases that differ radically in morphology, physiology and behaviour. Solitarious locusts are cryptic in appearance and behaviour, walking slowly with the body held close to the ground. Gregarious locusts are conspicuous in appearance and much more active, walking rapidly with the body held well above the ground. During walking, the excursion of the femoro-tibial (F-T) joint of the hind leg is smaller in solitarious locusts, and the joint is kept more flexed throughout an entire step. Under open loop conditions, the slow extensor tibiae (SETi) motor neurone of solitarious locusts shows strong tonic activity that increases at more extended F-T angles. SETi of gregarious locusts by contrast showed little tonic activity. Simulated flexion of the F-T joint elicits resistance reflexes in SETi in both phases, but regardless of the initial and final position of the leg, the spiking rate of SETi during these reflexes was twice as great in solitarious compared to gregarious locusts. This increased sensory-motor gain in the neuronal networks controlling postural reflexes in solitarious locusts may be linked to the occurrence of pronounced behavioural catalepsy in this phase similar to other cryptic insects such as stick insects. PMID:20416321

  4. Mass spectral determination of phenylacetonitrile (PAN) levels in body tissues of adult desert locust, Schistocerca gregaria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    : Wings and legs of the gregarious desert locust, Schistocerca gregaria have been shown to be release sites of phenylacetonitrile (PAN), the major adult male-produced pheromone. However, there is limited information on the distribution of PAN within the locust. Here we show, using gas chromatograph...

  5. Hydroxy juvenile hormones: new putative juvenile hormones biosynthesized by locust corpora allata in vitro.

    PubMed

    Darrouzet, E; Mauchamp, B; Prestwich, G D; Kerhoas, L; Ujváry, I; Couillaud, F

    1997-11-26

    The in vitro production of sesquiterpenoids was investigated by using corpora allata (CA) of the African locust Locusta migratoria migratorioides. Labeled products from unstimulated biosynthesis were extracted, purified by normal phase HPLC, and derivatized to determine the functional groups present. An extra hydroxyl group was detected in each of two juvenile hormone (JH) biosynthetic products. One compound, NP-8, was found to co-migrate with a chemically-synthesized (Z)-hydroxymethyl isomer, 12'-OH JH-III, but not with the (E)-hydroxymethyl isomer, 12-OH JH III. Mass spectral analyses further supported the identity of the synthetic material with that biosynthesized by the corpora allata. A second compound was identified as the 8'-OH JH-III based on spectroscopic analyses. 12'-OH JH-III exhibited morphogenetic activity when tested on the heterospecific Tenebrio test. These data suggest that 12'-OH JH-III and 8'-OH JH-III are additional biosynthetically-produced and biologically-active juvenile hormones, and constitute the first known members of the class of hydroxy juvenile hormones (HJHs). PMID:9398639

  6. INCOMES OF MIGRATORY AGRICULTURAL WORKERS.

    ERIC Educational Resources Information Center

    METZLER, WILLIAM H.; SARGENT, FREDERIC O.

    A SURVEY ON THE INCOME OF MIGRATORY WORKERS LOCATED IN SOUTH TEXAS DURING THE WINTER OF 1956-57 WAS PRESENTED. IN 446 HOUSEHOLDS SURVEYED, THERE WERE 1,334 WORKERS, APPROXIMATELY HALF OF THESE WERE HOUSEHOLD HEADS OR THEIR WIVES. WORKING WIVES WERE A LITTLE MORE THAN HALF AS NUMEROUS AS WORKING HUSBANDS. MOST OF THE HUSBANDS WERE 45 TO 54 YEARS OF…

  7. Pennsylvania Migratory Labor Program Report.

    ERIC Educational Resources Information Center

    Governor's Committee on Migratory Labor, Harrisburg, PA.

    Operating for the 18th year, the Pennsylvania Governor's Committee on Migratory Labor, which is charged with coordinating and bringing into focus the activities of various governmental and nongovernmental agencies relating to Pennsylvania's migrant workers, submits the present document as an annual report. Some specific areas reported on by…

  8. MIGRATORY LABOR IN WISCONSIN AGRICULTURE.

    ERIC Educational Resources Information Center

    ROSE, A. THOMAS

    A SERIES OF CHARTS RELATED TO MIGRATORY WORKERS IN WISCONSIN IS PRESENTED. THE TABLES DEPICT THE SEASONAL AGRICULTURAL AND FOOD PROCESSING EMPLOYMENT TIMETABLE OF MAJOR CROP ACTIVITIES, UTILIZATION OF MIGRANT WORKERS IN SUCH ACTIVITIES, MIGRANT WORKERS REGISTERED BY DISTRICT OFFICES, STATE OF RESIDENCE, STATE OF LAST EMPLOYMENT, AND STATE OF NEXT…

  9. Population Explosion in the Yellow-Spined Bamboo Locust Ceracris kiangsu and Inferences for the Impact of Human Activity

    PubMed Central

    Fan, Zhou; Jiang, Guo-Fang; Liu, Yu-Xiang; He, Qi-Xin; Blanchard, Benjamin

    2014-01-01

    Geographic distance and geographical barriers likely play a considerable role in structuring genetic variation in species, although some migratory species may have less phylogeographic structure on a smaller spatial scale. Here, genetic diversity and the phylogenetic structure among geographical populations of the yellow-spined bamboo locust, Ceracris kiangsu, were examined with 16S rDNA and amplified fragment length polymorphisms (AFLPs). In this study, no conspicuous phylogeographical structure was discovered from either Maximum parsimony (MP) and Neighbor-joining (NJ) phylogenetic analyses. The effect of geographical isolation was not conspicuous on a large spatial scale.At smaller spatial scales local diversity of some populations within mountainous areas were detected using Nei's genetic distance and AMOVA. There is a high level of genetic diversity and a low genetic differentiation among populations in the C. kiangsu of South and Southeast China. Our analyses indicate that C. kiangsu is a monophyletic group. Our results also support the hypothesis that the C. kiangsu population is in a primary differentiation stage. Given the mismatch distribution, it is likely that a population expansion in C. kiangsu occurred about 0.242 Ma during the Quaternary interglaciation. Based on historical reports, we conjecture that human activities had significant impacts on the C. kiangsu gene flow. PMID:24603526

  10. Population explosion in the yellow-spined bamboo locust Ceracris kiangsu and inferences for the impact of human activity.

    PubMed

    Fan, Zhou; Jiang, Guo-Fang; Liu, Yu-Xiang; He, Qi-Xin; Blanchard, Benjamin

    2014-01-01

    Geographic distance and geographical barriers likely play a considerable role in structuring genetic variation in species, although some migratory species may have less phylogeographic structure on a smaller spatial scale. Here, genetic diversity and the phylogenetic structure among geographical populations of the yellow-spined bamboo locust, Ceracris kiangsu, were examined with 16S rDNA and amplified fragment length polymorphisms (AFLPs). In this study, no conspicuous phylogeographical structure was discovered from either Maximum parsimony (MP) and Neighbor-joining (NJ) phylogenetic analyses. The effect of geographical isolation was not conspicuous on a large spatial scale.At smaller spatial scales local diversity of some populations within mountainous areas were detected using Nei's genetic distance and AMOVA. There is a high level of genetic diversity and a low genetic differentiation among populations in the C. kiangsu of South and Southeast China. Our analyses indicate that C. kiangsu is a monophyletic group. Our results also support the hypothesis that the C. kiangsu population is in a primary differentiation stage. Given the mismatch distribution, it is likely that a population expansion in C. kiangsu occurred about 0.242 Ma during the Quaternary interglaciation. Based on historical reports, we conjecture that human activities had significant impacts on the C. kiangsu gene flow. PMID:24603526

  11. The desert locust, Schistocerca gregaria, detoxifies the glucosinolates of Schouwia purpurea by desulfation.

    PubMed

    Falk, Kimberly L; Gershenzon, Jonathan

    2007-08-01

    Desert locusts (Schistocerca gregaria) occasionally feed on Schouwia purpurea, a plant that contains tenfold higher levels of glucosinolates than most other Brassicaceae. Whereas this unusually high level of glucosinolates is expected to be toxic and/or deterrent to most insects, locusts feed on the plant with no apparent ill effects. In this paper, we demonstrate that the desert locust, like larvae of the diamondback moth (Plutella xylostella), possesses a glucosinolate sulfatase in the gut that hydrolyzes glucosinolates to their corresponding desulfonated forms. These are no longer susceptible to cleavage by myrosinase, thus eliminating the formation of toxic glucosinolate hydrolysis products. Sulfatase is found throughout the desert locust gut and can catalyze the hydrolysis of all of the glucosinolates present in S. purpurea. The enzyme was detected in all larval stages of locusts as well as in both male and female adults feeding on this plant species. Glucosinolate sulfatase activity is induced tenfold when locusts are fed S. purpurea after being maintained on a glucosinolate-free diet, and activity declines when glucosinolates are removed from the locust diet. A detoxification system that is sensitive to the dietary levels of a plant toxin may minimize the physiological costs of toxin processing, especially for a generalist insect herbivore that encounters large variations in plant defense metabolites while feeding on different species. PMID:17619221

  12. Multisensor monitoring system for assessment of locust hazard risk in the Lake Balkhash drainage basin.

    PubMed

    Propastin, Pavel

    2012-12-01

    Satellite and ground-based data were combined in a monitoring system to quantify the link between climate conditions and the risk of locust infestations in the southern part of Lake Balkhash's drainage basin in the Republic of Kazakhstan. In this monitoring system, the Normalized Difference Vegetation Index (NDVI), derived from the SPOT-VGT satellite, was used for mapping potential locust habitats and monitoring their area throughout 1998 to 2007. TOPEX/Poseidon and Jason 1 altimeter data were used to track the interannual dynamics of water level in Balkhash Lake. Climate conditions were represented by weather records for air temperature and precipitation during the same period. The classification procedure, based on an analysis of multitemporal dynamics of SPOT-VGT NDVI values observed by individual vegetation classes, generated annual areas of ten land-cover types, which were then categorized as areas with low, medium, and high risk for locust infestation. Statistical analyses showed significant influences of the climatic parameters and the Balkhash Lake hydrological regime on the spatial extend of annual areas of potential locust habitats. The results also indicate that the linkages between locust infestation risk and environmental factors are characterized by time lags. The expansion of locust risk areas are usually preceded by dry, hot years and lower water levels in Balkhash Lake when larger areas of reed grass are free from seasonal flooding. Years with such conditions are favourable for locust outbreaks due to expansion of the habitat areas suitable for locust oviposition and nymphal development. In contrast, years with higher water levels in Balkhash Lake and lower temperature decrease the potential locust habitat area. PMID:22990684

  13. Social learning of migratory performance

    USGS Publications Warehouse

    Mueller, Thomas; O'Hara, Robert B.; Converse, Sarah J.; Urbanek, Richard P.; Fagan, William F.

    2013-01-01

    Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were captive bred and artificially trained by ultralight aircraft on their first lifetime migration. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy.

  14. Migratory birds, ticks, and Bartonella

    PubMed Central

    Molin, Ylva; Lindeborg, Mats; Nyström, Fredrik; Madder, Maxime; Hjelm, Eva; Olsen, Björn; Jaenson, Thomas G.T.; Ehrenborg, Christian

    2011-01-01

    Bartonella spp. infections are considered to be vector-borne zoonoses; ticks are suspected vectors of bartonellae. Migratory birds can disperse ticks infected with zoonotic pathogens such as Rickettsia and tick-borne encephalitis virus and possibly also Bartonella. Thus, in the present study 386 tick specimens collected in spring 2009 from migratory birds on the Mediterranean islands Capri and Antikythera were screened for Bartonella spp. RNA. One or more ticks were found on 2.7% of the birds. Most ticks were Hyalomma rufipes nymphs and larvae with mean infestation rates of 1.7 nymphs and 0.6 larvae per infested bird. Bartonella spp. RNA was not detected in any of the tick specimens. PMID:22957116

  15. Social learning of migratory performance.

    PubMed

    Mueller, Thomas; O'Hara, Robert B; Converse, Sarah J; Urbanek, Richard P; Fagan, William F

    2013-08-30

    Successful bird migration can depend on individual learning, social learning, and innate navigation programs. Using 8 years of data on migrating whooping cranes, we were able to partition genetic and socially learned aspects of migration. Specifically, we analyzed data from a reintroduced population wherein all birds were captive bred and artificially trained by ultralight aircraft on their first lifetime migration. For subsequent migrations, in which birds fly individually or in groups but without ultralight escort, we found evidence of long-term social learning, but no effect of genetic relatedness on migratory performance. Social learning from older birds reduced deviations from a straight-line path, with 7 years of experience yielding a 38% improvement in migratory accuracy. PMID:23990559

  16. Locust bean gum: processing, properties and food applications--a review.

    PubMed

    Barak, Sheweta; Mudgil, Deepak

    2014-05-01

    Locust bean gum or carob gum is a galactomannan obtained from seed endosperm of carob tree i.e. Ceratonia siliqua. It is widely utilized as an additive in various industries such as food, pharmaceuticals, paper, textile, oil well drilling and cosmetics. Industrial applications of locust bean gum are due to its ability to form hydrogen bonding with water molecule. It is also beneficial in the control of many health problems like diabetes, bowel movements, heart disease and colon cancer due to its dietary fiber action. This article focuses on production, processing, composition, properties, food applications and health benefits of locust bean gum. PMID:24548746

  17. Stress Preconditioning of Spreading Depression in the Locust CNS

    PubMed Central

    Rodgers, Corinne I.; Armstrong, Gary A. B.; Shoemaker, Kelly L.; LaBrie, John D.; Moyes, Christopher D.; Robertson, R. Meldrum

    2007-01-01

    Cortical spreading depression (CSD) is closely associated with important pathologies including stroke, seizures and migraine. The mechanisms underlying SD in its various forms are still incompletely understood. Here we describe SD-like events in an invertebrate model, the ventilatory central pattern generator (CPG) of locusts. Using K+ -sensitive microelectrodes, we measured extracellular K+ concentration ([K+]o) in the metathoracic neuropile of the CPG while monitoring CPG output electromyographically from muscle 161 in the second abdominal segment to investigate the role K+ in failure of neural circuit operation induced by various stressors. Failure of ventilation in response to different stressors (hyperthermia, anoxia, ATP depletion, Na+/K+ ATPase impairment, K+ injection) was associated with a disturbance of CNS ion homeostasis that shares the characteristics of CSD and SD-like events in vertebrates. Hyperthermic failure was preconditioned by prior heat shock (3 h, 45°C) and induced-thermotolerance was associated with an increase in the rate of clearance of extracellular K+ that was not linked to changes in ATP levels or total Na+/K+ ATPase activity. Our findings suggest that SD-like events in locusts are adaptive to terminate neural network operation and conserve energy during stress and that they can be preconditioned by experience. We propose that they share mechanisms with CSD in mammals suggesting a common evolutionary origin. PMID:18159249

  18. Pair bonds: arrival synchrony in migratory birds.

    PubMed

    Gunnarsson, T G; Gill, J A; Sigurbjörnsson, T; Sutherland, W J

    2004-10-01

    Synchronous arrival of pairs of migratory birds at their breeding grounds is important for maintaining pair bonds and is achieved by pairs that remain together all year round. Here we show that arrival is also synchronized in paired individuals of a migratory shorebird, the black-tailed godwit (Limosa limosa islandica), even though they winter hundreds of kilometres apart and do not migrate together. The mechanisms required to achieve this synchrony and prevent 'divorce' illustrate the complexity of migratory systems. PMID:15470417

  19. 75 FR 3888 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... Register on November 20, 2009 (74 FR 60228), to propose migratory bird subsistence harvest regulations in... Fish and Wildlife Service 50 CFR Part 92 RIN 1018-AW67 Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska During the 2010 Season AGENCY: Fish and Wildlife...

  20. ANCIENT TRANS-ATLANTIC FLIGHT EXPLAINS LOCUST BIOGEOGRAPHY: MOLECULAR PHYLOGENETICS OF SCHISTOCERCA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The desert locust (Schistocercagregaria) has been an important agricultural pest at least since biblical times. Although the ecology, physiology and behaviour of this insect species have been well characterized, its biogeographical origins and evolutionary history are more obscure. Schistocerca greg...

  1. ERTS surveys a 500 km squared locust breeding site in Saudi Arabia. [Red Sea coastal plain

    NASA Technical Reports Server (NTRS)

    Pedgley, D. E.

    1974-01-01

    From September 1972 to January 1973, ERTS-1 precisely located a 500 sq km area on the Red Sea coastal plain of Saudi Arabia within which the Desert Locust (Schistocerca gregaria, Forsk.) bred successfully and produced many small swarms. Growth of vegetation shown by satellite imagery was confirmed from ground surveys and raingauge data. The experiment demonstrates the feasibility of detecting potential locust breeding sites by satellite, and shows that an operational satellite would be a powerful tool for routine survey of the 3 x 10 to the 7th power sq km invasion area of the Desert Locust in Africa and Asia, as well as of other locust species in the arid and semi-arid tropics.

  2. Cytochemical demonstration of cyclic 3', 5' AMP phosphodiesterase in different tissue of migratory locust (Locusta migratoria migratorioides R.F.).

    PubMed

    Benedeczky, I; Rózsa, K S

    1981-01-01

    The localization of cyclic 3', 5'-AMP phosphodiesterase was studied by ultrastructural cytochemical methods in the various tissues of Locusta migratoria. Large amounts of electron dense, granular reaction products were detectable on the surface of the corpora allata and the corpus cardiacum, bound to the basal lamina. In the protocerebral neuropile rather large amounts of reaction products were observed in the processes of the glial cells. A significant number of lead phosphate deposit was found to occur on the membrane of certain large axons, the microtubules of the axons, furthermore on the membrane of several terminals. Reaction product was also observable in certain terminals, bound to the synaptic vesicles and the mitochondria. At the same time, electron dense deposits were not detectable at all on the surface of cerebral neurons. In the case of myocardium, reaction product was only found on the basal lamina and the extracellular surface of the sarcolemma. On the basis of our results it can be stated that the cyclic 3', 5'-AMP phosphodiesterase is detectable by cytochemical methods in different tissues of Locusta migratoria and presumably it fulfils the task of the extracellular cAMP level regulation. PMID:6260713

  3. Joint action of Beauveria bassiana and the insect growth regulators diflubenzuron and novaluron, on the migratory locust, Locusta migratoria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beauveria bassiana (Balsamo) Vuillemin and sublethal concentrations of the insect growth regulators (IGR) diflubenzuron and novaluron were applied simultaneously and sequentially to second instar Locusta migratoria migratorioides (Sauss.) to determine the interaction between these materials and an e...

  4. Design and implementation of geographic information systems, remote sensing, and global positioning system-based information platform for locust control

    NASA Astrophysics Data System (ADS)

    Li, Lin; Zhu, Dehai; Ye, Sijing; Yao, Xiaochuang; Li, Jun; Zhang, Nan; Han, Yueqi; Zhang, Long

    2014-01-01

    To monitor and control locusts efficiently, an information platform for locust control based on the global positioning system (GPS), remote sensing (RS), and geographic information systems (GIS) was developed. The platform can provide accurate information about locust occurrence and control strategies for a specific geographic place. The platform consists of three systems based on modern pest control: field ecology (locust occurrence) and GIS in a mobile GPS pad, a processing system for locust information based on GIS and RS, and a WebGIS-based real-time monitoring and controlling system. This platform was run at different geographical locations for three years and facilitated locust control in China with high efficiency and great accuracy.

  5. Microarray-Based Transcriptomic Analysis of Differences between Long-Term Gregarious and Solitarious Desert Locusts

    PubMed Central

    Badisco, Liesbeth; Ott, Swidbert R.; Rogers, Stephen M.; Matheson, Thomas; Knapen, Dries; Vergauwen, Lucia; Verlinden, Heleen; Marchal, Elisabeth; Sheehy, Matt R. J.; Burrows, Malcolm; Broeck, Jozef Vanden

    2011-01-01

    Desert locusts (Schistocerca gregaria) show an extreme form of phenotypic plasticity and can transform between a cryptic solitarious phase and a swarming gregarious phase. The two phases differ extensively in behavior, morphology and physiology but very little is known about the molecular basis of these differences. We used our recently generated Expressed Sequence Tag (EST) database derived from S. gregaria central nervous system (CNS) to design oligonucleotide microarrays and compare the expression of thousands of genes in the CNS of long-term gregarious and solitarious adult desert locusts. This identified 214 differentially expressed genes, of which 40% have been annotated to date. These include genes encoding proteins that are associated with CNS development and modeling, sensory perception, stress response and resistance, and fundamental cellular processes. Our microarray analysis has identified genes whose altered expression may enable locusts of either phase to deal with the different challenges they face. Genes for heat shock proteins and proteins which confer protection from infection were upregulated in gregarious locusts, which may allow them to respond to acute physiological challenges. By contrast the longer-lived solitarious locusts appear to be more strongly protected from the slowly accumulating effects of ageing by an upregulation of genes related to anti-oxidant systems, detoxification and anabolic renewal. Gregarious locusts also had a greater abundance of transcripts for proteins involved in sensory processing and in nervous system development and plasticity. Gregarious locusts live in a more complex sensory environment than solitarious locusts and may require a greater turnover of proteins involved in sensory transduction, and possibly greater neuronal plasticity. PMID:22132225

  6. Adaptive changes in locust kicking and jumping behaviour during development

    PubMed

    Norman

    1995-01-01

    The hind, or metathoracic, leg of a locust is specialised, enabling it to store energy that is used to extend the tibia rapidly during kicking and jumping; behaviours which share a common motor pattern. This study describes developmental changes in kicking and jumping behaviour and relates these changes to the development of the exoskeleton and jumping performance. In mature adults and intermoult larvae, the exoskeleton is strong and kicks can readily be elicited. Before and after the adult moult, when the exoskeleton is weak, kicks can be elicited less frequently, thus avoiding skeletal damage. At these times, animals do not generate the adult motor pattern for kicking, so that extension of the tibia is powered by direct muscle contraction, rather than through the release of stored energy. The muscles of all newly moulted animals are capable of generating sufficient force to damage the leg, but 14 days later the muscles can rarely generate sufficient force to damage the leg. To mimic the forces generated during the preparation for a kick, when the flexor and extensor tibiae muscles co-contract, the extensor muscle was stimulated electrically at a range of frequencies and the nature and occurrence of the resulting mechanical damage to components of the skeleton were assessed over a 14 day period following the adult moult. In newly moulted animals, the proximal femur partially collapses and thus protects the leg from damage before the muscles generate sufficient force to damage chronically other components of the leg. This partial collapse of the femur is reversible when the extensor muscle is activated at low frequency, but high frequencies cause permanent damage. The muscles of all animals 1 day after the moult are also capable of generating sufficient force to damage the leg, but the proximal tibia breaks most commonly in the region where the extensor muscle apodeme attaches. 5 days after the moult, the muscles in only 50 % of animals can damage the leg and most

  7. Listening to the environment: hearing differences from an epigenetic effect in solitarious and gregarious locusts

    PubMed Central

    Gordon, Shira D.; Jackson, Joseph C.; Rogers, Stephen M.; Windmill, James F. C.

    2014-01-01

    Locusts display a striking form of phenotypic plasticity, developing into either a lone-living solitarious phase or a swarming gregarious phase depending on population density. The two phases differ extensively in appearance, behaviour and physiology. We found that solitarious and gregarious locusts have clear differences in their hearing, both in their tympanal and neuronal responses. We identified significant differences in the shape of the tympana that may be responsible for the variations in hearing between locust phases. We measured the nanometre mechanical responses of the ear's tympanal membrane to sound, finding that solitarious animals exhibit greater displacement. Finally, neural experiments signified that solitarious locusts have a relatively stronger response to high frequencies. The enhanced response to high-frequency sounds in the nocturnally flying solitarious locusts suggests greater investment in detecting the ultrasonic echolocation calls of bats, to which they are more vulnerable than diurnally active gregarious locusts. This study highlights the importance of epigenetic effects set forth during development and begins to identify how animals are equipped to match their immediate environmental needs. PMID:25274362

  8. Reduced L-type Ca2+ current and compromised excitability induce loss of skeletal muscle function during acute cooling in locust.

    PubMed

    Findsen, Anders; Overgaard, Johannes; Pedersen, Thomas Holm

    2016-08-01

    Low temperature causes most insects to enter a state of neuromuscular paralysis, termed chill coma. The susceptibility of insect species to chill coma is tightly correlated to their distribution limits and for this reason it is important to understand the cellular processes that underlie chill coma. It is known that muscle function is markedly depressed at low temperature and this suggests that chill coma is partly caused by impairment in the muscle per se. To find the cellular mechanism(s) underlying muscle dysfunction at low temperature, we examined the effect of low temperature (5°C) on several events in excitation-contraction coupling in the migratory locust (Locusta migratoria). Intracellular membrane potential recordings during single nerve stimulations showed that 70% of fibers at 20°C produced an action potential (AP), while only 55% of fibers were able to fire an AP at 5°C. Reduced excitability at low temperature was caused by an ∼80% drop in L-type Ca(2+) current and a depolarizing shift in its activation of around 20 mV, which means that a larger endplate potential would be needed to activate the muscle AP at low temperature. In accordance, we showed that intracellular Ca(2+) transients were largely absent at low temperature following nerve stimulation. In contrast, maximum contractile force was unaffected by low temperature in chemically skinned muscle bundles, which demonstrates that the function of the contractile filaments is preserved at low temperature. These findings demonstrate that reduced L-type Ca(2+) current is likely to be the most important factor contributing to loss of muscle function at low temperature in locust. PMID:27247315

  9. Using a mobile robot to study locust collision avoidance responses.

    PubMed

    Blanchard, M; Verschure, P F; Rind, F C

    1999-10-01

    The visual systems of insects perform complex processing using remarkably compact neural circuits, yet these circuits are often studied using simplified stimuli which fail to reveal their behaviour in more complex visual environments. We address this issue by testing models of these circuits in real-world visual environments using a mobile robot. In this paper we focus on the lobula giant movement detector (LGMD) system of the locust which responds selectively to objects which approach the animal on a collision course and is thought to trigger escape behaviours. We show that a neural network model of the LGMD system shares the preference for approaching objects and detects obstacles over a range of speeds. Our results highlight aspects of the basic response properties of the biological system which have important implications for the behavioural role of the LGMD. PMID:10630469

  10. Increased muscular volume and cuticular specialisations enhance jump velocity in solitarious compared with gregarious desert locusts, Schistocerca gregaria.

    PubMed

    Rogers, Stephen M; Riley, Joanna; Brighton, Caroline; Sutton, Gregory P; Cullen, Darron A; Burrows, Malcolm

    2016-03-01

    The desert locust, Schistocerca gregaria, shows a strong phenotypic plasticity. It can develop, depending upon population density, into either a solitarious or gregarious phase that differs in many aspects of behaviour, physiology and morphology. Prominent amongst these differences is that solitarious locusts have proportionately longer hind femora than gregarious locusts. The hind femora contain the muscles and energy-storing cuticular structures that propel powerful jumps using a catapult-like mechanism. We show that solitarious locusts jump on average 23% faster and 27% further than gregarious locusts, and attribute this improved performance to three sources: first, a 17.5% increase in the relative volume of their hind femur, and hence muscle volume; second, a 24.3% decrease in the stiffness of the energy-storing semi-lunar processes of the distal femur; and third, a 4.5% decrease in the stiffness of the tendon of the extensor tibiae muscle. These differences mean that solitarious locusts can generate more power and store more energy in preparation for a jump than can gregarious locusts. This improved performance comes at a cost: solitarious locusts expend nearly twice the energy of gregarious locusts during a single jump and the muscular co-contraction that energises the cuticular springs takes twice as long. There is thus a trade-off between achieving maximum jump velocity in the solitarious phase against the ability to engage jumping rapidly and repeatedly in the gregarious phase. PMID:26936638

  11. Mapping Global Diversity Patterns for Migratory Birds

    PubMed Central

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H. M.; Rodrigues, Ana S. L.

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world’s birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective. PMID:23951037

  12. Mapping global diversity patterns for migratory birds.

    PubMed

    Somveille, Marius; Manica, Andrea; Butchart, Stuart H M; Rodrigues, Ana S L

    2013-01-01

    Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes) where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective. PMID:23951037

  13. Identifying the breeding areas of locusts in the Yellow River estuary using Landsat ETM+ imagery

    NASA Astrophysics Data System (ADS)

    Liu, Qingsheng; Liu, Gaohuan; Yang, Yuzhen; Liu, Peng; Huang, Jianjie

    2006-03-01

    The Yellow River Estuary became an important plague region of locusts because of its special geographic location. Many years' survey data showed that the environment was the chief factor that influenced locust pest occurring. In the recent years, because the amount of water from the Yellow River and precipitation reduced and distributed asymmetrically, and soil salinization became serious much more, and many farmlands went out of cultivation, which improved the habitats for locusts, the plague of locusts happened frequently under condign climate. The field survey data from 1991 to 2000 showed that the plague of locust became more aggravating year after year. Therefore, it is important to monitor and control the plague of locusts. According to many years' investigation data analysis, got the condign habitat conditions for Locusta Migratoria Manilensis (Meyen) in the Yellow River Estuary. So the breeding areas of locusts monitoring with remote sensing imagery was to identify those regions according to the condign habitat conditions. Landsat ETM+ imagery (2000-05-02) data was chosen to identify the breeding areas of locusts in the Yellow River Estuary. Firstly classified Landsat TM imagery (2000-5-2) and extract reed lands and lawn lands and slightly salinized soils. Secondly made mask images through transforming these three raster classes into vector layers, then calculated a anti-atmospheric visible light vegetation index VARIg = (B2-B3)/(B2+B3-B1). According to field investigation data of vegetation fractional cover in 2000, got the relationship between vegetation fractional cover and VARIg values, 70% to 3.0, 50% to 2.3. As a result, the infrequent areas were where VARIg values were great than 3.0, and the moderate areas were where VARIg values were between 2.3 and 3.0, and frequent areas were where VARIg values were under 2.3. According to statistical analysis, the infrequent areas were percent 10 of the lands that have the condign soil salt content for locust

  14. An analysis of the contrasting fates of locust swarms on the plains of North America and East Asia

    NASA Astrophysics Data System (ADS)

    Yu, G.; Ke, X.; Shen, H. D.; Li, Y. F.

    2013-03-01

    Prior to ~1880 AD locust swarms periodically raged across both the North American Plains (NAP) and East Asian Plains (EAP). After this date, locust outbreaks almost never recurred on the NAP but have continued to cause problems on the EAP. The large quantities of pesticides used in the major agriculture regions of the NAP in the late 1870s have been suggested as a possible reason for the disappearance of locust outbreaks in this area. Extensive applications of modern, i.e. more effective, chemical pesticides were also used in the granary regions of the EAP in the 1950s in an effort to reduce pest outbreaks. However, locust swarms returned again in many areas of China in the 1960s. Therefore, locust extinction on the NAP still remains a puzzle. Frequent locust outbreaks on the EAP over the past 130 yr may offer clues to the key factors that control the disappearance of locust outbreaks on the NAP. This study analysed the climate extremes and monthly temperature-precipitation combinations for the NAP and EAP, and found that differences in the frequencies of these climate combinations resulted in the contrasting locust fates in the two regions: restricting locust outbreaks in the NAP but inducing such events in the EAP. Validation shows that severe EAP locust outbreak years were coincidental with extreme climate-combination years. Therefore, we suggest that changes in frequency, extremes and trends in climate can explain why the fate of locust outbreaks in the EAP was different from that in the NAP. The results also suggest that, with present global warming trends, precautionary measures should be taken to make sure other similar pest infestations do not occur in either region.

  15. A~probe into the different fates of locust swarms in the plains of North America and East Asia

    NASA Astrophysics Data System (ADS)

    Yu, G.; Johnson, D.; Ke, X.; Li, Y.

    2012-08-01

    Locust swarms had periodically raged in both North American Plains (NAP) and East Asian Plains (EAP) before 1880 AD. After this period, the locust outbreaks almost never recurred in NAP but have continued to occur in EAP. Since large quantities of pesticides were used in the major agriculture regions of NAP in the late 1870s; this has been suggested as a possible major cause of the disappearing of locust outbreaks. Extensive applications of more effective chemical pesticides were also used in the granary regions of EAP in the 1950s in an effort to kill the pests at a much higher intensity. However, locust swarms came back again in many areas of China in the 1960s. Therefore, NAP locust extinction still remains a puzzle. Frequent locust outbreaks in EAP over the past 130 yr may offer clues to probe key control elements in the disappearing of locust outbreaks in NAP. This paper analyzes the climate extremes and monthly temperature-precipitation combines of NAP and EAP, and found the differences in their frequencies of these climate combines caused different locust fates in the two regions: restrained the locust outbreak in NAP but induced such events in EAP. Validation shows that severer EAP locust outbreak years were coincided with the climate extreme combines years. Thus we suggest that climate changes in frequency, extremes and trends can explain why the fate of the locust plague in EAP was different from that in NAP. The study also points out that, under the present global warming, cautions should be taken to make sure the pest hazard being nipped in the-bud.

  16. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey....

  17. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... provided at 50 CFR 2.1(b). (b) General provisions. Each person hunting migratory game birds in any State... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird...

  18. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey....

  19. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey....

  20. 50 CFR 20.20 - Migratory Bird Harvest Information Program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Migratory Bird Harvest Information Program... IMPORTATION OF WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Taking § 20.20 Migratory Bird Harvest... information will be used to provide a sampling frame for the national Migratory Bird Harvest Survey....

  1. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  2. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  3. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  4. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  5. 50 CFR 20.40 - Gift of migratory game birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Gift of migratory game birds. 20.40... WILDLIFE AND PLANTS (CONTINUED) MIGRATORY BIRD HUNTING Possession § 20.40 Gift of migratory game birds. No person may receive, possess, or give to another, any freshly killed migratory game birds as a...

  6. Insects in relation to black locust culture on surface-mine spoil in Kentucky, with emphasis on the locust twig borer, Ecdytolopha insiticiana Zell. (Lepidoptera: Tortricidae)

    SciTech Connect

    Thoeny, W.T.

    1986-01-01

    This research evaluated the impacts of herbivorous insects, emphasizing the locust twig borer, Ecdytolopha insiticiana Zeller, on black locust, Robinia pseudoacacia L., coppice production on a coal surface-mine spoil site in southeastern Kentucky. The natural history of E. insiticiana was also studied. The locust twig borer was a persistent and damaging pest in first-year coppice, which provided suitable larval habitat throughout the growing season. The locust leafminer, Odontota dorsalis (Thunberg), fed minimally on first-year coppice foliage except during 1983, when trees were severely drought-stressed. Soil-applied granular carbofuran significantly reduced infestations. Lindane stem treatments were not effective, but entire-tree applications did reduce herbivory. Stump sprouts with reduced levels of herbivory grew significantly taller than controls at both spacings in 1983, but only at the more dense spacing in 1984. Blacklight trap collections revealed two generations/year, and adults were present from early May until late August. Four species of hymenopterous and two species of dipterous parasitoids were recovered from E. insiticiana larvae.

  7. A case study of the Australian Plague Locust Commission and environmental due diligence: why mere legislative compliance is no longer sufficient for environmentally responsible locust control in Australia.

    PubMed

    Story, Paul G; Walker, Paul W; McRae, Heath; Hamilton, John G

    2005-07-01

    The Australian Plague Locust Commission (APLC) manages locust populations across 2 million square kilometers of eastern Australia using the aerial application of chemical and biological control agents to protect agricultural production. This occurs via a preventative control strategy involving ultralow-volume spray equipment to distribute small droplets of control agent over a target area. The economic costs of, and potential gains stemming from, locust control are well documented. The application of insecticides, however, to fragile arid and semiarid ecosystems is a task that brings with it both real and perceived environmental issues. The APLC is proactive in addressing these issues through a combination of targeted environmental operational research, an ISO-14001-aligned Environmental Management System (EMS), and links with environmental regulatory and research institutions. Increasing due diligence components within Australian environmental legislation dictate that mere legislative compliance is no longer sufficient for industries to ensure that they meet their environmental obligations. The development of external research links and the formulation of an EMS for locust control have enabled the APLC to identify environmental issues and trends, quantify objective environmental targets and strategies, and facilitate continuous improvement in its environmental performance, while maintaining stakeholder support. This article outlines the environmental issues faced by the APLC, the research programs in place to address these issues, and the procedures in place to incorporate research findings into the organization's operational structure. PMID:16639885

  8. Non-swarming grasshoppers exhibit density-dependent phenotypic plasticity reminiscent of swarming locusts.

    PubMed

    Gotham, Steven; Song, Hojun

    2013-11-01

    Locusts are well known for exhibiting an extreme form of density-dependent phenotypic plasticity known as locust phase polyphenism. At low density, locust nymphs are cryptically colored and shy, but at high density they transform into conspicuously colored and gregarious individuals. Most of what we know about locust phase polyphenism come from the study of the desert locust Schistocerca gregaria (Forskål), which is a devastating pest species affecting many countries in North Africa and the Middle East. The desert locust belongs to the grasshopper genus Schistocerca Stål, which includes mostly non-swarming, sedentary species. Recent phylogenetic studies suggest that the desert locust is the earliest branching lineage within Schistocerca, which raises a possibility that the presence of density-dependent phenotypic plasticity may be a plesiomorphic trait for the whole genus. In order to test this idea, we have quantified the effect of rearing density in terms of the resulting behavior, color, and morphology in two non-swarming Schistocerca species native to Florida. When reared in both isolated and crowded conditions, the two non-swarming species, Schistocerca americana (Drury) and Schistocerca serialis cubense (Saussure) clearly exhibited plastic reaction norms in all traits measured, which were reminiscent of the desert locust. Specifically, we found that both species were more active and more attracted to each other when reared in a crowded condition than in isolation. They were mainly bright green in color when isolated, but developed strong black patterns and conspicuous background colors when crowded. We found a strong effect of rearing density in terms of size. There were also more mechanoreceptor hairs on the outer face of the hind femora in the crowded nymphs in both species. Although both species responded similarly, there were some clear species-specific differences in terms of color and behavior. Furthermore, we compare and contrast our findings with

  9. Daily microhabitat shifting of solitarious-phase Desert locust adults: implications for meaningful population monitoring.

    PubMed

    Maeno, Koutaro Ould; Ould Ely, Sidi; Nakamura, Satoshi; Abdellaoui, Khemais; Cissé, Sory; Jaavar, Mohamed El Hacen; Ould Mohamed, Sid'Ahmed; Atheimine, Mohamed; Ould Babah, Mohamed Abdallahi

    2016-01-01

    The Desert locust Schistocerca gregaria is a major world pest that causes substantial agricultural and economic damage. Effective pest control relies on effective monitoring, which requires knowledge of locust microhabitat selection. Yet little is known about microhabitat selection of solitarious adult locusts in the field. We conducted field surveys to investigate fine-scale diel temporal and spatial distributions of solitarious adults in the Sahara Desert in Mauritania, a major breeding and recession area. We found that solitarious adults moved among different, specific microhabitats throughout the 24-h period in a cyclical manner. At night, they roosted in trees, moved to the ground to feed shortly after dawn, sheltered in low vegetation during the hot midday, and returned to the ground in the late afternoon. Hence, they switched microhabitats and plant species throughout each day. These cyclical daily movements among diverse microhabitats and specific plant species were correlated with time of day, light intensity, temperature, humidity, and specific plant species, and may relate to anti-predator defence, thermoregulation, and feeding. The present study suggests that locust monitoring should be adjusted, based on time of day, locust age, phase state and relative abundance of specific plant species. For example, we recommend surveying ground after morning and trees at night, for solitarious adults, when at low density. PMID:26877905

  10. Identification of a chitinase-producing bacterium C4 and histopathologic study on locusts.

    PubMed

    Yong, Tao; Zhangfu, Long; Jing, Xie; Hong, Jin; Hongyan, Ran; Ke, Tao; Shaorong, Ge; Kun, Liu; Shigui, Liu

    2005-02-01

    In order to develop the potential of chitinase-producing micro-organisms as biocontrol agents for insect pests, five chitinase-producing bacterial strains (C1, C2, C3, C4 and C5) previously isolated from soil samples were chosen to infect grassland locusts. The data showed that the mortality rate of locusts fed with strain C4 was significantly higher than that of other groups, and its pathogenicity was confirmed by Koch's law. Midgut tissues of locusts infected with C4 were examined with a light microscope. Apparent histopathologic changes in midgut cells partly explained the pathogenesis of locusts. Therefore, strain C4 was considered to be a potential biocontrol agent. To determine the taxonomic position of C4, physiological and biochemical characteristics were determined and molecular identification was performed. The 16S rDNA gene of C4 was amplified, cloned and sequenced. Comparative sequence analysis demonstrated that C4 corresponded to the genera Sanguibacter, Oerskovia and Cellulomonas. On the basis of phenotypic characterization and sequence similarity analysis, strain C4 was more closely related to the genus Sanguibacter. This chitinase-producing strain C4, which closely corresponds to the species of the genus Sanguibacter and is pathogenic to locusts, is here reported for the first time. PMID:15619732

  11. Metabolomic analysis reveals that carnitines are key regulatory metabolites in phase transition of the locusts.

    PubMed

    Wu, Rui; Wu, Zeming; Wang, Xianhui; Yang, Pengcheng; Yu, Dan; Zhao, Chunxia; Xu, Guowang; Kang, Le

    2012-02-28

    Phenotypic plasticity occurs prevalently and plays a vital role in adaptive evolution. However, the underlying molecular mechanisms responsible for the expression of alternate phenotypes remain unknown. Here, a density-dependent phase polyphenism of Locusta migratoria was used as the study model to identify key signaling molecules regulating the expression of phenotypic plasticity. Metabolomic analysis, using high-performance liquid chromatography and gas chromatography-mass spectrometry, showed that solitarious and gregarious locusts have distinct metabolic profiles in hemolymph. A total of 319 metabolites, many of which are involved in lipid metabolism, differed significantly in concentration between the phases. In addition, the time course of changes in the metabolic profiles of locust hemolymph that accompany phase transition was analyzed. Carnitine and its acyl derivatives, which are involved in the lipid β-oxidation process, were identified as key differential metabolites that display robust correlation with the time courses of phase transition. RNAi silencing of two key enzymes from the carnitine system, carnitine acetyltransferase and palmitoyltransferase, resulted in a behavioral transition from the gregarious to solitarious phase and the corresponding changes of metabolic profiles. In contrast, the injection of exogenous acetylcarnitine promoted the acquisition of gregarious behavior in solitarious locusts. These results suggest that carnitines mediate locust phase transition possibly through modulating lipid metabolism and influencing the nervous system of the locusts. PMID:22328148

  12. Variation in chemosensitivity and the control of dietary selection behaviour in the locust.

    PubMed

    Simpson, S J; James, S; Simmonds, M S; Blaney, W M

    1991-10-01

    Investigations into the behavioural and underlying physiological mechanisms of dietary selection are presented for the locust, Locusta migratoria. Locusts were fed for 4, 8 or 12 h on one of four chemically defined artificial diets: diet PC, which was nutritionally complete; diet P, containing no digestible carbohydrate; diet C, containing no protein; and diet O, which lacked both protein and digestible carbohydrate. Following this pretreatment, the locusts were provided with both the P and the C diet in a choice test. Detailed analyses of selection behaviour indicated that diets lacking a nutrient for which the insect was deficient were either rejected before a meal was initiated, or, if feeding commenced, eaten in meals of only short duration, while those containing the appropriate nutrients were accepted more readily and eaten in longer meals. Electrophysiological studies showed that this behaviour was paralleled by nutrient-specific changes in gustatory responsiveness. Locusts pretreated for 4h on C diet had increased gustatory responsiveness to stimulation with an amino acid mix, but not to sucrose, while insects fed on P diet showed increased responsiveness to stimulation with sucrose, but not to the amino acid mix. This result is consistent with earlier experiments in which levels of blood nutrients were shown to modulate taste responsiveness in the locust. PMID:1763906

  13. Metabolomic analysis reveals that carnitines are key regulatory metabolites in phase transition of the locusts

    PubMed Central

    Wu, Rui; Wu, Zeming; Wang, Xianhui; Yang, Pengcheng; Yu, Dan; Zhao, Chunxia; Xu, Guowang; Kang, Le

    2012-01-01

    Phenotypic plasticity occurs prevalently and plays a vital role in adaptive evolution. However, the underlying molecular mechanisms responsible for the expression of alternate phenotypes remain unknown. Here, a density-dependent phase polyphenism of Locusta migratoria was used as the study model to identify key signaling molecules regulating the expression of phenotypic plasticity. Metabolomic analysis, using high-performance liquid chromatography and gas chromatography–mass spectrometry, showed that solitarious and gregarious locusts have distinct metabolic profiles in hemolymph. A total of 319 metabolites, many of which are involved in lipid metabolism, differed significantly in concentration between the phases. In addition, the time course of changes in the metabolic profiles of locust hemolymph that accompany phase transition was analyzed. Carnitine and its acyl derivatives, which are involved in the lipid β-oxidation process, were identified as key differential metabolites that display robust correlation with the time courses of phase transition. RNAi silencing of two key enzymes from the carnitine system, carnitine acetyltransferase and palmitoyltransferase, resulted in a behavioral transition from the gregarious to solitarious phase and the corresponding changes of metabolic profiles. In contrast, the injection of exogenous acetylcarnitine promoted the acquisition of gregarious behavior in solitarious locusts. These results suggest that carnitines mediate locust phase transition possibly through modulating lipid metabolism and influencing the nervous system of the locusts. PMID:22328148

  14. Satellite normalized difference vegetation index data used in managing Australian plague locusts

    NASA Astrophysics Data System (ADS)

    Deveson, Edward D.

    2013-01-01

    The Australian Plague Locust Commission (APLC) has a mandated role in monitoring, forecasting, and managing populations of key locust species across four Australian states. Satellite normalized difference vegetation index (NDVI) imagery is used to monitor vegetation condition in locust habitat and is integrated with mapping software to support forecasting and operations within the strategic framework of APLC activities. The usefulness of NDVI data for monitoring locust habitats is tested using historical control and survey records for the Australian plague locust, Chortoicetes terminifera (Walker). In arid habitat areas, control of high-density nymphal populations was consistently associated with high and increased relative NDVI during summer and autumn, providing important information for locating possible infestations. Regression models of NDVI data and regional biogeographic factors were fitted to summer survey records of C. terminifera presence and abundance. Models identified increased vegetation greenness, measured by a one-month positive change in NDVI, as having a significant positive relationship with nymph distributions, while NDVI was significant in adult distributions. Seasonal rainfall regions and a binary habitat stratification were significant explanatory factors in all models.

  15. Health care for pesticide applicators in a locust eradication campaign in Kuwait (1988-1989).

    PubMed

    Al-Shatti, A K; El-Desouky, M; Zaki, R; Abu Al-Azem, M; Al-Lagani, M

    1997-01-01

    Pesticide applicators in the Plant Protection Department of the Agriculture Affairs and Fish Resources Authority are monitored regularly by the Occupational Health Section of the Ministry of Health. The aim is to protect them from the adverse effects of pesticides and to prevent acute poisoning by removing from exposure those who have low cholinesterase (ChE) activity levels or low white blood cell counts. Thirty-eight workers routinely examined in July 1988 were reexamined at the onset of the locust invasion in Kuwait in November 1988; also examined were 36 farmers recruited for the first time to fight locusts and a matched control group of 38 firefighters. After 2 to 3 months, when the locust invasion decreased markedly and pesticide spraying nearly stopped, the exposed workers were reexamined. The pesticides used to control locusts were five organophosphates and one organochlorine (lindane). Sixty percent of normal for red blood cell (RBC) ChE activity and 50% of normal for plasma ChE activity were used as threshold levels for removing workers from continued exposure to ChE-inhibiting pesticides. The different reactions of study groups during the locust control period are described, including results from tests of pulmonary function, RBC and plasma ChE activity, and nerve conduction velocity. PMID:9311551

  16. Quantitative assessment of Australian plague locust habitats in the inland of eastern Australia using RS and GIS technologies

    NASA Astrophysics Data System (ADS)

    Wang, Haikou

    2014-10-01

    Australian Plague Locust, Chortoicetes terminifera (Walker), can rapidly increase in population size in the remote interior of eastern Australia under favorable habitat conditions and cause severe agricultural damage. To minimize losses, earlydetection of locust outbreaks is essential to the implementation of preventive control. Quantitative measurement of locust habitat suitability is critical for improving the efficiency of ground and aerial surveys, and providing vital information for locust population forecasting. Here, routine locust survey by the Australian Plague Locust Commission during 2003 and 2011 is investigated in relation to the habitat greenness derived from the fortnightly 250 m composites of Normalized Difference Vegetation Index (NDVI), and the rainfall amount from the weekly 5 km grids of modelled precipitation, using the spatial analysis and statistics of ESRI ArcGIS. The sighting dates of high-density locust nymphs (band and sub-band) were assigned into 5 groups corresponding to the nymphal development stages, and the fortnightly NDVI values and weekly rainfall totals for the locust locations were extracted for the previous 13 weeks. The averaged NDVI values for locust habitats showed a slight increase of 0.04-0.13 from initially 0.23-0.29 within 4-7 weeks before 2nd-5th instar bands and sub-bands were sighted. The median values of NDVI increase were on an equivalence scale of 0.05-0.15 from the background of 0.21-0.26; the increments were equal to 12-37% in the historical range from 13-22% and equal to 38-59% from the 11-18% of seasonal maxima, which indicated by normalized NDVI anomalies that the majority of high-density nymphs had all experienced a period of better than average conditions in both historical and seasonal perspectives. However, 5th-instar bands and sub-bands were consistently found in slightly dried habitats, while 1st-instar bands were mostly seen in much green areas but on the trend of dry-off. The time-series of habitat

  17. Classification of odorants across layers in locust olfactory pathway.

    PubMed

    Sanda, Pavel; Kee, Tiffany; Gupta, Nitin; Stopfer, Mark; Bazhenov, Maxim

    2016-05-01

    Olfactory processing takes place across multiple layers of neurons from the transduction of odorants in the periphery, to odor quality processing, learning, and decision making in higher olfactory structures. In insects, projection neurons (PNs) in the antennal lobe send odor information to the Kenyon cells (KCs) of the mushroom bodies and lateral horn neurons (LHNs). To examine the odor information content in different structures of the insect brain, antennal lobe, mushroom bodies and lateral horn, we designed a model of the olfactory network based on electrophysiological recordings made in vivo in the locust. We found that populations of all types (PNs, LHNs, and KCs) had lower odor classification error rates than individual cells of any given type. This improvement was quantitatively different from that observed using uniform populations of identical neurons compared with spatially structured population of neurons tuned to different odor features. This result, therefore, reflects an emergent network property. Odor classification improved with increasing stimulus duration: for similar odorants, KC and LHN ensembles reached optimal discrimination within the first 300-500 ms of the odor response. Performance improvement with time was much greater for a population of cells than for individual neurons. We conclude that, for PNs, LHNs, and KCs, ensemble responses are always much more informative than single-cell responses, despite the accumulation of noise along with odor information. PMID:26864765

  18. The effect of octopamine on the locust stomatogastric nervous system.

    PubMed

    Rand, David; Knebel, Daniel; Ayali, Amir

    2012-01-01

    Octopamine (OA) is a prominent neuromodulator of invertebrate nervous systems, influencing multiple physiological processes. Among its many roles in insects are the initiation and maintenance of various rhythmic behaviors. Here, the neuromodulatory effects of OA on the components of the locust stomatogastric nervous system were studied, and one putative source of OA modulation of the system was identified. Bath application of OA was found to abolish the endogenous rhythmic output of the fully isolated frontal ganglion (FG), while stimulating motor activity of the fully isolated hypocerebral ganglion (HG). OA also induced rhythmic movements in a foregut preparation with intact HG innervation. Complex dose-dependent effects of OA on interconnected FG-HG preparations were seen: 10(-5) M OA accelerated the rhythmic activity of both the HG and FG in a synchronized manner, while 10(-4) M OA decreased both rhythms. Intracellular stimulation of an identified octopaminergic dorsal unpaired median neuron in the subesophageal ganglion was found to exert a similar effect on the FG motor output as that of OA application. Our findings suggest a mechanism of regulation of insect gut patterns and feeding-related behavior during stress and times of high energy demand. PMID:22934040

  19. Inhalable Antitubercular Therapy Mediated by Locust Bean Gum Microparticles.

    PubMed

    Alves, Ana D; Cavaco, Joana S; Guerreiro, Filipa; Lourenço, João P; Rosa da Costa, Ana M; Grenha, Ana

    2016-01-01

    Tuberculosis remains a major global health problem and alternative therapeutic approaches are needed. Considering the high prevalence of lung tuberculosis (80% of cases), the pulmonary delivery of antitubercular drugs in a carrier system capable of reaching the alveoli, being recognised and phagocytosed by alveolar macrophages (mycobacterium hosts), would be a significant improvement to current oral drug regimens. Locust bean gum (LBG) is a polysaccharide composed of galactose and mannose residues, which may favour specific recognition by macrophages and potentiate phagocytosis. LBG microparticles produced by spray-drying are reported herein for the first time, incorporating either isoniazid or rifabutin, first-line antitubercular drugs (association efficiencies >82%). Microparticles have adequate theoretical properties for deep lung delivery (aerodynamic diameters between 1.15 and 1.67 μm). The cytotoxic evaluation in lung epithelial cells (A549 cells) and macrophages (THP-1 cells) revealed a toxic effect from rifabutin-loaded microparticles at the highest concentrations, but we may consider that these were very high comparing with in vivo conditions. LBG microparticles further evidenced strong ability to be captured by macrophages (percentage of phagocytosis >94%). Overall, the obtained data indicated the potential of the proposed system for tuberculosis therapy. PMID:27240337

  20. Migratory diversity predicts population declines in birds.

    PubMed

    Gilroy, James J; Gill, Jennifer A; Butchart, Stuart H M; Jones, Victoria R; Franco, Aldina M A

    2016-03-01

    Declines in migratory species are a pressing concern worldwide, but the mechanisms underpinning these declines are not fully understood. We hypothesised that species with greater within-population variability in migratory movements and destinations, here termed 'migratory diversity', might be more resilient to environmental change. To test this, we related map-based metrics of migratory diversity to recent population trends for 340 European breeding birds. Species that occupy larger non-breeding ranges relative to breeding, a characteristic we term 'migratory dispersion', were less likely to be declining than those with more restricted non-breeding ranges. Species with partial migration strategies (i.e. overlapping breeding and non-breeding ranges) were also less likely to be declining than full migrants or full residents, an effect that was independent of migration distance. Recent rates of advancement in Europe-wide spring arrival date were greater for partial migrants than full migrants, suggesting that migratory diversity may also help facilitate species responses to climate change. PMID:26807694

  1. AN ODORANT-BINDING PROTEIN INVOLVED IN PERCEPTION OF HOST PLANT ODORANTS IN LOCUST Locusta migratoria.

    PubMed

    Li, Jia; Zhang, Long; Wang, Xiaoqi

    2016-04-01

    Locusts, Locusta migratoria (Orthoptera: Acrididae), are extremely destructive agricultural pests, but very little is known of their molecular aspects of perception to host plant odorants including related odorant-binding proteins (OBPs), though several OBPs have been identified in locust. To elucidate the function of LmigOBP1, the first OBP identified from locust, RNA interference was employed in this study to silence LmigOBP1, which was achieved by injection of dsRNA targeting LmigOBP1 into the hemolymph of male nymphs. Compared with LmigOBP1 normal nymphs, LmigOBP1 knockdown nymphs significantly decreased food (maize leaf, Zea mays) consumption and electro-antennography responses to five maize leaf volatiles, ((Z)-3-hexenol, linalool, nonanal, decanal, and (Z)-3-hexenyl acetate). These suggest that LmigOBP1 is involved in perception of host plant odorants. PMID:26864243

  2. Microwave assisted synthesis of acrylamide grafted locust bean gum and its application in drug delivery.

    PubMed

    Kaity, Santanu; Isaac, Jinu; Kumar, P Mahesh; Bose, Anirbandeep; Wong, Tin Wui; Ghosh, Animesh

    2013-10-15

    Acrylamide grafted copolymer of locust bean gum was prepared by microwave irradiation using ceric ammonium nitrate as redox initiator. The grafting process was optimized in terms of irradiation time, amount of initiator and acrylamide by using constant amount of native locust bean gum. The grafted gum was characterized by Fourier transform infrared spectroscopy (FT-IR), (13)C nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), X-ray diffraction study (XRD), differential scanning calorimetry (DSC), elemental analysis, contact angle, viscosity, molecular weight, swelling and biodegradability studies. The grafted gum was found to be biodegradable and non-toxic. It was further used to prepare controlled-release matrix tablet of buflomedil hydrochloride. The in vitro release profile of the tablet showed the rate controlling property of acrylamide grafted locust bean gum was similar to that of hydroxypropyl methylcellulose (HPMC-K15M). PMID:23987450

  3. Stopping a walking locust with sound: an analysis of variation in behavioural threshold.

    PubMed

    Moorhouse, J E; Fosbrooke, I H; Ludlow, A R

    1987-01-01

    Pulses of 3 kHz sound, varying in intensity from 46 dB SPL to 113 dB SPL (reference value = 20 microPa), were presented to fifth instar larvae of the locust Locusta migratoria migratorioides (R. and F.) walking on a recording treadmill. Walking locusts either responded to the sound by stopping within 2.1 s of its presentation or they continued walking apparently unaffected by it. The latency of the stopping response was correlated with stimulus intensity: the higher the stimulus intensity, the sooner the locust stopped walking. Pauses induced by sounds were longer than those that occurred 'spontaneously' and increased in duration with increasing stimulus intensity. This relationship, however, was modulated by walking speed: the faster the locust was walking, the shorter the following pause for a given stimulus intensity. The intensity of sound needed to elicit a response depended on the length of time the locust had spent in uninterrupted walking before the stimulus was presented. The stopping threshold for sound stimuli presented 3 s into the walking bout was 84 dB SPL (SE +/- 1.56), and at 20 s it was significantly less, at 76 dB SPL (SE +/- 1.56). This effect of time was significant even when other factors, such as differences between individual locusts, were allowed for in the regression analysis. This shift in the behavioural threshold could not be explained simply by on-going changes in walking behaviour, for although the speed of walking was correlated with stopping threshold its effect was not statistically significant when differences between individuals and time of stimulus presentation were allowed for in the regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3582590

  4. Optimizing energy yields in black locust through genetic selection: final report

    SciTech Connect

    Bongarten, B.C.; Merkle, S.A.

    1996-10-01

    The purpose of this work was to assess the magnitude of improvement in biomass yield of black locust possible through breeding, and to determine methods for efficiently capturing the yield improvement achievable from selective breeding. To meet this overall objective, six tasks were undertaken to determine: (1) the amount and geographic pattern of natural genetic variation, (2) the mating system of the species, (3) quantitative genetic parameters of relevant traits, (4) the relationship between nitrogen fixation and growth in black locust, (5) the viability of mass vegetative propagation, and (6) the feasibility of improvement through genetic transformation.

  5. Locust invasions and climatic factors from the Middle Ages to 1800

    NASA Astrophysics Data System (ADS)

    Camuffo, D.; Enzi, S.

    1991-03-01

    Locust migrations are strictly connected with climatic factors and a historical reconstruction of their invasions in Europe may be useful in dealing with this plague. From records of medieval chroniclers and more recent sources till 1800, some 100 detailed descriptions of locust invasions have been collected and analyzed. Some of them include the meteorological conditions which were associated with the arrival of the swarm of locusts, their path and the presumed country of origin, as well as the local effects such as famine and epidemics, these latter being mostly due to the putrification of the dead locusts. Once in Italy, by comparing different chronicles it is also possible to reconstruct the local march of the bands of hoppers, their extension, the periods in which they more frequently appear, the impact on human settlements, and sometimes the climatic factors (drop of temperature) which caused the swarm to die. The frequent observation of bands with “locusts and crickets” refers to hoppers of different instars, some of them in mature stage and others immature or moulting, born in convenient climatic conditions. By comparing the various chronicles it was also possible to reconstruct the local trajectory of the swarms, their extension, the periods when they were most frequent, their impact on the towns and villages and sometimes the climatic factors (mostly sharp drops in the temperature) responsible for the death of the swarms in northern and central Italy. According to the documentation perused, central-northern Italy was infested via two routes: 1) in most cases the locusts travelled up the Danube basin, then channelled through the Dinaric Alps and the Carpathians thus reaching the Hungarian Plain, and then being transported by the eastern winds to Italy; 2) very occasionally there were local invasions from the north, when the locusts descended through the Brenner Pass after reaching the Danube basin, and then moving along the Inn valley down to the River

  6. Onset of collective motion in locusts is captured by a minimal model

    NASA Astrophysics Data System (ADS)

    Dyson, Louise; Yates, Christian A.; Buhl, Jerome; McKane, Alan J.

    2015-11-01

    We present a minimal model to describe the onset of collective motion seen when a population of locusts are placed in an annular arena. At low densities motion is disordered, while at high densities locusts march in a common direction, which may reverse during the experiment. The data are well captured by an individual-based model, in which demographic noise leads to the observed density-dependent effects. By fitting the model parameters to equation-free coefficients, we give a quantitative comparison, showing time series, stationary distributions, and the mean switching times between states.

  7. Onset of collective motion in locusts is captured by a minimal model.

    PubMed

    Dyson, Louise; Yates, Christian A; Buhl, Jerome; McKane, Alan J

    2015-11-01

    We present a minimal model to describe the onset of collective motion seen when a population of locusts are placed in an annular arena. At low densities motion is disordered, while at high densities locusts march in a common direction, which may reverse during the experiment. The data are well captured by an individual-based model, in which demographic noise leads to the observed density-dependent effects. By fitting the model parameters to equation-free coefficients, we give a quantitative comparison, showing time series, stationary distributions, and the mean switching times between states. PMID:26651724

  8. 78 FR 65955 - Migratory Bird Permits; Control Order for Introduced Migratory Bird Species in Hawaii

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... eradication and control. These include staff of the Kauai Invasive Species Committee, the Oahu Invasive... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AZ69 Migratory Bird Permits; Control Order for Introduced Migratory Bird Species in Hawaii AGENCY: Fish and Wildlife Service, Interior. ACTION:...

  9. 75 FR 32872 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-10

    ...We, the U.S. Fish and Wildlife Service (Service), proposed in an earlier document to establish annual hunting regulations for certain migratory game birds for the 2010-11 hunting season. This supplement to the proposed rule provides the regulatory schedule, announces the Service Migratory Bird Regulations Committee and Flyway Council meetings, and provides Flyway Council recommendations......

  10. 75 FR 29917 - Migratory Bird Permits; Changes in the Regulations Governing Migratory Bird Rehabilitation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-28

    ... FR 61123) to establish regulations for the issuance of permits to rehabilitate migratory birds in the... Relations with Native American Tribal Governments'' (59 FR 22951), Executive Order 13175, and 512 DM 2, we... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX09 Migratory Bird Permits; Changes in...

  11. 78 FR 67183 - Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Bird Harvest Information Program and Migratory Bird Surveys AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice; request for... Bird Treaty Act (16 U.S.C. 703-711) and the Fish and Wildlife Act of 1956 (16 U.S.C. 742d)...

  12. 76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-03

    ... authorizing the referenced incidental take in the Federal Register on February 28, 2007 (72 FR 8931). The... Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by the Armed Forces AGENCY: Fish and... (Authorization Act) provided interim authority to members of the Armed Forces to incidentally take...

  13. 78 FR 75321 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-11

    ...The U.S. Fish and Wildlife Service (Service or we) proposes migratory bird subsistence harvest regulations in Alaska for the 2014 season. These regulations would enable the continuation of customary and traditional subsistence uses of migratory birds in Alaska and prescribe regional information on when and where the harvesting of birds may occur. These regulations were developed under a......

  14. Behavior of geladas and other endemic wildlife during a desert locust outbreak at Guassa, Ethiopia: ecological and conservation implications.

    PubMed

    Fashing, Peter J; Nguyen, Nga; Fashing, Norman J

    2010-07-01

    Desert locust (Schistocerca gregaria) outbreaks have occurred repeatedly throughout recorded history in the Horn of Africa region, devastating crops and contributing to famines. In June 2009, a desert locust swarm invaded the Guassa Plateau, Ethiopia, a large and unusually intact Afroalpine tall-grass ecosystem, home to important populations of geladas (Theropithecus gelada), Ethiopian wolves (Canis simensis), thick-billed ravens (Corvus crassirostris), and other Ethiopian or Horn of Africa endemics. During the outbreak and its aftermath, we observed many animals, including geladas, ravens, and a wolf, feeding on locusts in large quantities. These observations suggest surprising flexibility in the normally highly specialized diets of geladas and wolves, including the potential for temporary but intensive insectivory during locust outbreaks. To our knowledge, Guassa is the highest elevation site (3,200-3,600 m) at which desert locusts, which require temperatures >20 degrees C for sustained flight, have been reported. Continued monitoring will be necessary to determine whether the June 2009 outbreak was an isolated incident or part of an emerging pattern in the Ethiopian Highlands linked to global warming. The intensive consumption of desert locusts by geladas, wolves, and ravens during the outbreak at Guassa raises concerns about pesticide-based locust control strategies and potential unintended adverse effects on endemic and endangered wildlife. PMID:20333438

  15. Application of sugar maple and black locust to the biomass/energy plantation concept. Interim report, March 1, 1980-February 28, 1981. [Sugar Maples, Black Locusts

    SciTech Connect

    Not Available

    1981-03-01

    The objective of the research program is to determine the feasibility of converting existing pole-size maple stands to biomass/energy plantations using black locust as an interplanted species. Toward this end, progress has been made in quantifying sprout biomass. Significant differences have been identified in productivity by site, species, time of fertilizer application, and diameter and damage of stumps. Rhizobium strains for black locust have been identified which are tolerant of low pH and phosphorous and high aluminum levels. Frost-hardy black locust seed sources have been identified for future work. Methods for sampling and equations for young natural stands of maple have been developed. Detailed characterization of sugar and red maple sprouts by physical, chemical and thermal analysis were compared to those of old, mature trees. The results are discussed in terms of seasonal moisture content variation, effects of tree age on specific gravity, extractive contents, ash content, major cell wall components, heating values and thermal behavior. 7 references, 5 figures, 17 tables.

  16. Coding of odors by temporal binding within a model network of the locust antennal lobe

    PubMed Central

    Patel, Mainak J.; Rangan, Aaditya V.; Cai, David

    2013-01-01

    The locust olfactory system interfaces with the external world through antennal receptor neurons (ORNs), which represent odors in a distributed, combinatorial manner. ORN axons bundle together to form the antennal nerve, which relays sensory information centrally to the antennal lobe (AL). Within the AL, an odor generates a dynamically evolving ensemble of active cells, leading to a stimulus-specific temporal progression of neuronal spiking. This experimental observation has led to the hypothesis that an odor is encoded within the AL by a dynamically evolving trajectory of projection neuron (PN) activity that can be decoded piecewise to ascertain odor identity. In order to study information coding within the locust AL, we developed a scaled-down model of the locust AL using Hodgkin–Huxley-type neurons and biologically realistic connectivity parameters and current components. Using our model, we examined correlations in the precise timing of spikes across multiple neurons, and our results suggest an alternative to the dynamic trajectory hypothesis. We propose that the dynamical interplay of fast and slow inhibition within the locust AL induces temporally stable correlations in the spiking activity of an odor-dependent neural subset, giving rise to a temporal binding code that allows rapid stimulus detection by downstream elements. PMID:23630495

  17. Diacylglycerol-carrying lipoprotein of hemolymph of the locust and some insects.

    PubMed

    Chino, H; Kitazawa, K

    1981-09-01

    The diacylglycerol-carrying lipoprotein (DGLP) was purified from hemolymph of the locust, Locusta migratoria, by a rapid method which included a specific precipitation at low ionic concentration and DEAE-cellulose column chromatography. The final preparation was highly homogeneous as judged by gel electrophoresis, electron microscopy, and immunodiffusion. The locust DGLP molecule was almost spherical in shape with a diameter of about 130 A. The molecular weight, determined by a sedimentation equilibrium method, was approximately 580,000. The total lipid content amounted to about 40%. The lipids comprised diacylglycerol (33% of total lipid), hydrocarbon (21%), cholesterol (8%), and phospholipids (36%). The hydrocarbon fraction contained a number of n-alkanes and methylalkanes ranging from C25 to C38 in chain length. Mannose (3%) and glucosamine (0.5%) were associated with the apoprotein of DGLP. Apoprotein of locust DGLP consisted of two subunits, heavy chain (mol wt 250,000) and light chain (mol wt 85,000); carbohydrate (mannose) was associated only with the heavy chain. Tests of physiological function of DGLPs from locust, cockroach, and silkworm suggest that the insect DGLP serves multiple roles as a true carrier molecule in transporting diacylglycerol, cholesterol, and hydrocarbon from sites of storage, absorption, and synthesis to sites where these lipids are utilized as metabolic fuel, precursors for triacylglycerol and phospholipid synthesis, or structural components of cell membrane and cuticle. In addition, the insect DGLPs displayed no species-specificity in terms of the functions, whereas they were immunologically distinguishable. PMID:6795289

  18. Body condition constrains immune function in field populations of female Australian plague locust Chortoicetes terminifera.

    PubMed

    Graham, R I; Deacutis, J M; Simpson, S J; Wilson, K

    2015-05-01

    The insect innate immune system comprises both humoral and cellular defence responses. In the laboratory, the insect immune system is well characterized. In the field, however, little is known about the role of constitutive insect immune function and how it varies within and between populations. Laboratory studies suggest that host nutrition has significant impact upon insect immune function. Thus, the rationale for this study was to sample natural populations of the Australian Plague Locust Chortoicetes terminifera to establish whether locust body condition (as determined by protein and lipid content) impacted their constitutive immune system and, as a result, has the potential to impact on their capacity to respond to a pathogenic challenge. We found that body condition varied greatly between individual female locusts within sites and that haemolymph protein levels, but not body lipid content, varied between sites. Moreover, our measures of immune function were correlated with the haemolymph levels of protein (in the case of haemocyte density), lipid (prophenoloxidase activity) or both (lysozyme-like antimicrobial activity). We discuss the implications of these findings for the role of biological pesticides in the control of locust populations. PMID:25677076

  19. Simultaneous measurement of aerodynamic forces and kinematics in flapping wings of tethered locust.

    PubMed

    Shkarayev, Sergey; Kumar, Rajeev

    2015-12-01

    Aerodynamic and inertial forces and corresponding kinematics of flapping wings of locusts, Schistocerca americana, were investigated in a low-speed wind tunnel. The experimental setup included live locusts mounted on microbalance synchronized with a high-speed video system. Simultaneous measurements of wing kinematics and forces were carried out on three locusts at 7° angle of attack and velocities of 0 m s(-1) and 4 m s(-1). Time variations of flapping and pitching angles exhibit similar patterns in fore- and hindwings and among the animals. Significant tip to root variations in pitching angle are found in both wings. The locusts have much larger flapping and pitching amplitudes in still air causing larger oscillations in inertial forces. Inertial forces are added to the lift and thrust on one part of the stroke, resulting in higher reaction forces and subtracted on the other part. Plots of the lift demonstrate similar trends with and without the wind. The global maxima and peak-to-peak amplitudes in lift are about the same in both tests. However, local minima are significantly lower in still air, resulting in much smaller stroke-averaged lift. Amplitudes of thrust force oscillations are much higher in still air; consequently, the stroke-averaged thrust is higher compared to the non-zero freestream velocity case. PMID:26496206

  20. Modeling spatiotemporal dynamics of outbreaking species: influence of environment and migration in a locust.

    PubMed

    Veran, Sophie; Simpson, Stephen J; Sword, Gregory A; Deveson, Edward; Piry, Sylvain; Hines, James E; Berthier, Karine

    2015-03-01

    Many pest species exhibit huge fluctuations in population abundance. Understanding their large-scale and long-term dynamics is necessary to develop effective control and management strategies. Occupancy models represent a promising approach to unravel interactions between environmental factors and spatiotemporal dynamics of outbreaking populations. Here, we investigated population dynamics of the Australian plague locust, Chortoicetes terminifera, using density data collected between 1988 and 2010 by the Australian Plague Locust Commission over more than 3 million km2 in eastern Australia. We applied multistate and autologistic multi-season occupancy models to test competing hypotheses about environmental and demographic processes affecting the large-scale dynamics of the Australian plague locust. We found that rainfall and land cover predictors best explained the spatial variability in outbreak probability across eastern Australia. Outbreaks are more likely to occur in temperate than tropical regions, with a faster and more continuous response to rainfall in desert than in agricultural areas. Our results also support the hypothesis that migration tends to propagate outbreaks only locally (over distances lower than 400 km) rather than across climatic regions. Our study suggests that locust outbreak forecasting and management systems could be improved by implementing key environmental factors and migration in hierarchical spatial models. Finally, our modeling framework can be seen as a step towards bridging the gap between mechanistic and more phenomenological models in the spatial analysis of fluctuating populations. PMID:26236870

  1. From release to absorption: Elucidating the effects of a desert locust pheromone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used a glass-vial bioassay to test the contact effect of the desert locust pheromone phenylacetonitrile (PAN) on nymphs and adults after 2 hand 4 h respectively, and quantified the amount of the pheromone absorbed and released by the nymphs after 2 h and 12 h. We also monitored the knockdown effe...

  2. Hydroponic screening of black locust families for heavy metal tolerance and accumulation.

    PubMed

    Župunski, Milan; Borišev, Milan; Orlović, Saša; Arsenov, Danijela; Nikolić, Nataša; Pilipović, Andrej; Pajević, Slobodanka

    2016-01-01

    Present work examines phytoextraction potential of four black locust families (half-sibs 54, 56, 115, and 135) grown hydroponically. Plants were treated with 6 ppm of cadmium (Cd), 100 ppm of nickel (Ni), and 40 ppm of lead (Pb) added in Hoagland nutrient solution, accompanying with simultaneously applied all three metals. Responses to metals exposure among families were different, ranging from severe to slight reduction of root and shoot biomass production of treated plants. Calculated tolerance indices are indicating tested families as highly tolerant (Ti > 60). Family 135 had the lowest tolerance index, pointing that it was highly susceptible to applied metals. Comparing photosynthetic activities of tested families it has been noticed that they were highly sensitive to stress induced by heavy metals. Net photosynthetic rate of nickel treated plants was the most affected by applied concentration. Cadmium and nickel concentrations in stems and leaves of black locust families exceeded 100 mg Cd kg(-1) and 1000 mg Ni kg(-1), in both single and multipollution context. On the contrary, accumulation of lead in above ground biomass was highly affected by multipollution treatment. Tf and BCF significantly varied between investigated treatments and families of black locust. Concerning obtained results of heavy metals accumulation and tolerance of black locust families can be concluded that tested families might be a promising tool for phytoextraction purposes, but it takes to be further confirmed in field trials. PMID:26332106

  3. Flexible seasonal timing and migratory behavior: results from stonechat breeding programs.

    PubMed

    Helm, Barbara; Gwinner, Eberhard; Trost, Lisa

    2005-06-01

    Rigid schedules of long-distance migrants could be among candidate traits for adaptive migratory syndromes. This prediction was tested on stonechats, passerines that differ widely in migratory behavior and seasonal schedules. Stonechats in Europe are short-distance migrants and multiclutched, whereas African residents and Siberian long-distance migrants usually raise single broods. In captivity, all subspecies displayed endogenous cycles of reproductive development and molt. The subspecies differed in time afforded to life cycle stages. Under conducive aviary conditions, African stonechats were multibrooded, whereas Siberian stonechats did not add clutches. This difference in flexibility was exclusively related to the length of breeding windows. Stonechats also differed in premigratory preparations. Postjuvenile molt started early in Siberian stonechats, but in European and African stonechats, depended strongly on hatching date. In contrast, all subspecies shortened molt duration at the same rate when hatched from late broods. Plasticity of Zugunruhe timing was identical in Siberian and European subspecies and nearly compensated for hatching late. The stonechat data suggest a refined understanding of temporal plasticity in long-distance migrants. Overall, plasticity was not reduced, but was differently organized. Apparently rigid migrant schedules were related to short breeding cycles and inflexible molt onset. Short windows for breeding and juvenile development could provide safety measures for timely departure. Once molt was initiated, temporal plasticity of long-distance migrants matched that of less migratory conspecifics. In addition to adjusting endogenous programs, stonechats differed in implementing them in the field. Modifying the conditions under which programs are expressed may be an efficient way to enhance seasonal plasticity. PMID:16055855

  4. Unraveling navigational strategies in migratory insects

    PubMed Central

    Merlin, Christine; Heinze, Stanley; Reppert, Steven M.

    2011-01-01

    Long-distance migration is a strategy some animals use to survive a seasonally changing environment. To reach favorable grounds, migratory animals have evolved sophisticated navigational mechanisms that rely on a map and compasses. In migratory insects, the existence of a map sense (sense of position) remains poorly understood, but recent work has provided new insights into the mechanisms some compasses use for maintaining a constant bearing during long-distance navigation. The best-studied directional strategy relies on a time-compensated sun compass, used by diurnal insects, for which neural circuits have begun to be delineated. Yet, a growing body of evidence suggests that migratory insects may also rely on other compasses that use night sky cues or the Earth's magnetic field. Those mechanisms are ripe for exploration. PMID:22154565

  5. Nonlinear time-periodic models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria

    PubMed Central

    Taylor, Graham K; Żbikowski, Rafał

    2005-01-01

    Previous studies of insect flight control have been statistical in approach, simply correlating wing kinematics with body kinematics or force production. Kinematics and forces are linked by Newtonian mechanics, so adopting a dynamics-based approach is necessary if we are to place the study of insect flight on its proper physical footing. Here we develop semi-empirical models of the longitudinal flight dynamics of desert locusts Schistocerca gregaria. We use instantaneous force–moment measurements from individual locusts to parametrize the nonlinear rigid body equations of motion. Since the instantaneous forces are approximately periodic, we represent them using Fourier series, which are embedded in the equations of motion to give a nonlinear time-periodic (NLTP) model. This is a proper mathematical generalization of an earlier linear-time invariant (LTI) model of locust flight dynamics, developed using previously published time-averaged versions of the instantaneous force recordings. We perform various numerical simulations, within the fitted range of the model, and across the range of body angles used by free-flying locusts, to explore the likely behaviour of the locusts upon release from the tether. Solutions of the NLTP models are compared with solutions of the nonlinear time-invariant (NLTI) models to which they reduce when the periodic terms are dropped. Both sets of models are unstable and therefore fail to explain locust flight stability fully. Nevertheless, whereas the measured forces include statistically significant harmonic content up to about the eighth harmonic, the simulated flight trajectories display no harmonic content above the fundamental forcing frequency. Hence, manoeuvre control in locusts will not directly reflect subtle changes in the higher harmonics of the wing beat, but must operate on a coarser time-scale. A state-space analysis of the NLTP models reveals orbital trajectories that are impossible to capture in the LTI and NLTI models

  6. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  7. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  8. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  9. 78 FR 66684 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-06

    ... National Oceanic and Atmospheric Administration RIN 0648-XC960 Atlantic Highly Migratory Species; Advisory... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers the...: ``HMS AP Nominations.'' Mail: Jenni Wallace, Highly Migratory Species Management Division, NMFS,...

  10. 78 FR 3446 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2013-14 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior,...

  11. 77 FR 1718 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... Fish and Wildlife Service Migratory Bird Hunting; Service Regulations Committee Meeting AGENCY: Fish... issues concerning the 2012-13 migratory bird hunting regulations. DATES: The meeting will be held... CONTACT: Chief, Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of...

  12. 78 FR 78377 - Migratory Bird Hunting; Service Regulations Committee Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-26

    ... Fish and Wildlife Service RIN 1018-AZ80 Migratory Bird Hunting; Service Regulations Committee Meeting... preliminary issues concerning the 2014-15 migratory bird hunting regulations. DATES: The meeting will be held..., Division of Migratory Bird Management, U.S. Fish and Wildlife Service, Department of the Interior,...

  13. 77 FR 60381 - Migratory Bird Conservation; Executive Order 13186

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-03

    ... National Oceanic and Atmospheric Administration RIN 0648-XC148 Migratory Bird Conservation; Executive Order... the U.S. Fish and ] Wildlife Service (FWS) to promote the conservation of migratory birds. DATES: This... Migratory Birds''. One of the requirements of E.O. 13186 is that each Federal agency taking actions...

  14. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  15. 50 CFR 92.22 - Subsistence migratory bird species.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Subsistence migratory bird species. 92.22... (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA General Regulations Governing Subsistence Harvest § 92.22 Subsistence migratory bird species. You may harvest birds or...

  16. The response of migratory populations to phenological change: a Migratory Flow Network modelling approach.

    PubMed

    Taylor, Caz M; Laughlin, Andrew J; Hall, Richard J

    2016-05-01

    Declines in migratory species have been linked to anthropogenic climate change through phenological mismatch, which arises due to asynchronies between the timing of life-history events (such as migration) and the phenology of available resources. Long-distance migratory species may be particularly vulnerable to phenological change in their breeding ranges, since the timing of migration departure is based on environmental cues at distant non-breeding sites. Migrants may, however, be able to adjust migration speed en route to the breeding grounds, and thus, ability of migrants to update their timing of migration may depend critically on stopover frequency during migration; however, understanding how migratory strategy influences population dynamics is hindered by a lack of predictive models explicitly linking habitat quality to demography and movement patterns throughout the migratory cycle. Here, we present a novel modelling framework, the Migratory Flow Network (MFN), in which the seasonally varying attractiveness of breeding, winter and stopover regions drives the direction and timing of migration based on a simple general flux law. We use the MFN to investigate how populations respond to shifts in breeding site phenology based on their frequency of stopover and ability to detect and adapt to these changes. With perfect knowledge of advancing phenology, 'jump' migrants (low-frequency stopover) require more adaptation for populations to recover than 'hop' and 'skip' (high or medium frequency stopover) migrants. If adaptation depends on proximity, hop and skip migrants' populations can recover but jump migrants cannot adjust and decline severely. These results highlight the importance of understanding migratory strategies and maintaining high-quality stopover habitat to buffer migratory populations from climate-induced mismatch. We discuss how MFNs could be applied to diverse migratory taxa and highlight the potential of MFNs as a tool for exploring how migrants

  17. Cryptochrome expression in the eye of migratory birds depends on their migratory status.

    PubMed

    Fusani, Leonida; Bertolucci, Cristiano; Frigato, Elena; Foà, Augusto

    2014-03-15

    Most passerine birds are nocturnal migrants. When kept in captivity during the migratory periods, these species show a migratory restlessness, or Zugunruhe. Recent studies on Sylvia warblers have shown that Zugunruhe is an excellent proxy of migratory disposition. Passerine birds can use the Earth's geomagnetic field as a compass to keep their course during their migratory flight. Among the candidate magnetoreceptive mechanisms are the cryptochromes, flavoproteins located in the retina that are supposed to perceive the magnetic field through a light-mediated process. Previous work has suggested that expression of Cryptochrome 1 (Cry1) is increased in migratory birds compared with non-migratory species. Here we tested the hypothesis that Cry1 expression depends on migratory status. Blackcaps Sylvia atricapilla were caught before fall migration and held in registration cages. When the birds were showing robust Zugunruhe, we applied a food deprivation protocol that simulates a long migratory flight. When the birds were refed after 2 days, their Zugunruhe decreased substantially, as is expected from birds that would interrupt migration for a refuelling stopover. We found that Cry1 expression was higher at night than during daytime in birds showing Zugunruhe, whereas in birds that underwent the fasting-and-refeeding protocol and reduced their levels of Zugunruhe, night Cry1 expression decreased to daytime levels. Our work shows that Cry1 expression is dependent on the presence of Zugunruhe and not on species-specific or seasonal factors, or on the birds being active versus inactive. These results support the hypothesis that cryptochromes underlie magnetoreceptive mechanisms in birds. PMID:24622895

  18. MIGRATORY LABOR IN COLORADO. PROGRESS REPORT.

    ERIC Educational Resources Information Center

    SIMPSON, RAY; AND OTHERS

    DEVELOPMENTS, FROM 1950 THROUGH 1960, ARE TRACED CONCERNING MIGRATORY LABOR IN COLORADO IN THE AREAS OF EMPLOYMENT, WAGE RATES, MINIMUM WAGE LEGISLATION, EMPLOYMENT OF MEXICAN NATIONALS, EDUCATION, HEALTH, HOUSING, SANITATION, WELFARE, UNEMPLOYMENT COMPENSATION, WORKMEN'S COMPENSATION COVERAGE, AND THE LICENSING AND REGULATION OF LABOR CONTRACTORS…

  19. MIGRATORY AGRICULTURAL WORKERS IN THE UNITED STATES.

    ERIC Educational Resources Information Center

    JORGENSON, JANET M.; AND OTHERS

    FIELD STUDIES WERE CONDUCTED IN 1960 IN THE LOWER RIO GRANDE VALLEY OF TEXAS AND IN IOWA TO AUGMENT INFORMATION ON MIGRATORY WORKERS. FACULTY-STUDENT TEAM FIELD TRIPS FOUND MANY FACTORS TO CONSIDER IN PROVIDING A CONSTRUCTIVE APPROACH TO THE PROBLEMS OF THE MIGRANT WORKER. CHILDREN OF THE MIGRANTS ARE NOT GETTING THE EDUCATION THEY NEED TO BREAK…

  20. MIGRATORY WORKERS IN THE UNITED STATES.

    ERIC Educational Resources Information Center

    1965

    THE NEED FOR LARGE NUMBERS OF FARM WORKERS FOR SHORT PERIODS DURING THE CULTIVATION AND HARVESTING OF CROPS IN WIDELY SEPARATED AREAS RESULTS IN A MIGRATORY WORK FORCE OF APPROXIMATELY 400,000 PERSONS EACH YEAR. MIGRANTS ARE EMPLOYED TO AVOID LOSSES OF PERISHABLE CROPS IN THE FIELDS, TO TAKE ADVANTAGE OF GOOD WEATHER OR TO FORESTALL LOSSES DUE TO…

  1. Photoperiodic response may facilitate adaptation to climatic change in long-distance migratory birds.

    PubMed Central

    Coppack, Timothy; Pulido, Francisco; Czisch, Michael; Auer, Dorothee P; Berthold, Peter

    2003-01-01

    Recent climatic change is causing spring events in northern temperate regions to occur earlier in the year. As a result, migratory birds returning from tropical wintering sites may arrive too late to take full advantage of the food resources on their breeding grounds. Under these conditions, selection will favour earlier spring arrival that could be achieved by overwintering closer to the breeding grounds. However, it is unknown how daylength conditions at higher latitudes will affect the timing of life cycle stages. Here, we show in three species of Palaearctic-African migratory songbirds that a shortening of migration distance induces an advancement of springtime activities. Birds exposed to daylengths simulating migration to and wintering in southern Europe considerably advanced their spring migratory activity and testicular development. This response to the novel photoperiodic environment will enable birds wintering further north to advance spring arrival and to start breeding earlier. Thus, phenotypic flexibility in response to the photoperiod may reinforce selection for shorter migration distance if spring temperatures continue to rise. PMID:12952632

  2. Photoperiodic response may facilitate adaptation to climatic change in long-distance migratory birds.

    PubMed

    Coppack, Timothy; Pulido, Francisco; Czisch, Michael; Auer, Dorothee P; Berthold, Peter

    2003-08-01

    Recent climatic change is causing spring events in northern temperate regions to occur earlier in the year. As a result, migratory birds returning from tropical wintering sites may arrive too late to take full advantage of the food resources on their breeding grounds. Under these conditions, selection will favour earlier spring arrival that could be achieved by overwintering closer to the breeding grounds. However, it is unknown how daylength conditions at higher latitudes will affect the timing of life cycle stages. Here, we show in three species of Palaearctic-African migratory songbirds that a shortening of migration distance induces an advancement of springtime activities. Birds exposed to daylengths simulating migration to and wintering in southern Europe considerably advanced their spring migratory activity and testicular development. This response to the novel photoperiodic environment will enable birds wintering further north to advance spring arrival and to start breeding earlier. Thus, phenotypic flexibility in response to the photoperiod may reinforce selection for shorter migration distance if spring temperatures continue to rise. PMID:12952632

  3. Disentangling Migratory Routes and Wintering Grounds of Iberian Near-Threatened European Rollers Coracias garrulus

    PubMed Central

    Rodríguez-Ruiz, Juan; de la Puente, Javier; Parejo, Deseada; Valera, Francisco; Calero-Torralbo, Miguel A.; Reyes-González, José M.; Zajková, Zuzana; Bermejo, Ana; Avilés, Jesús M.

    2014-01-01

    Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1) a mainly nocturnal flying activity, 2) that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3) that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller. PMID:25551212

  4. Disentangling migratory routes and wintering grounds of Iberian near-threatened European Rollers Coracias garrulus.

    PubMed

    Rodríguez-Ruiz, Juan; de la Puente, Javier; Parejo, Deseada; Valera, Francisco; Calero-Torralbo, Miguel A; Reyes-González, José M; Zajková, Zuzana; Bermejo, Ana; Avilés, Jesús M

    2014-01-01

    Long-distance migrants are suffering drastic declines in the last decades. Causes beneath this problem are complex due to the wide spatial and temporal scale involved. We aim to reveal migratory routes, stopover areas, wintering grounds, and migratory strategies for the most southwestern populations of the near-threatened European Roller Coracias garrulus in order to identify conservation key areas for the non-breeding stage of this species. To this end, we used tracking data from seven satellite transmitters fitted to birds breeding in different populations throughout the Iberian Peninsula and four geolocators fitted to individuals in a southeastern Iberian population. Precise satellite data were used to describe daily activity patterns and speed in relation to the main regions crossed during the migration. Individuals from the most southwestern Iberian populations made a detour towards the Atlantic African coast whereas those from northeastern populations followed a straight north-to-south route. We identified important stopover areas in the Sahel belt, mainly in the surroundings of the Lake Chad, and wintering grounds on southwestern Africa farther west than previously reported for the species. Concerning the migratory strategy, satellite data revealed: 1) a mainly nocturnal flying activity, 2) that migration speed depended on the type of crossed habitat, with higher average speed while crossing the desert; and 3) that the migration was slower and lasted longer in autumn than in spring. The studied populations showed weak migratory connectivity, suggesting the confluence of birds from a wide range of breeding grounds in a restricted wintering area. Therefore, we suggest to target on defining precisely key areas for this species and identifying specific threats in them in order to develop an appropriate global conservation programme for the European Roller. PMID:25551212

  5. Identification of the gregarization-associated dark-pigmentotropin in locusts through an albino mutant

    PubMed Central

    Tawfik, Amer I.; Tanaka, Seiji; De Loof, Arnold; Schoofs, Liliane; Baggerman, Geert; Waelkens, Etienne; Derua, Rita; Milner, Yoram; Yerushalmi, Yoram; Pener, M. Paul

    1999-01-01

    In response to crowding, locusts develop characteristic black patterns that are well discernible in the gregarious phase at outbreaks. We report here a dark-color-inducing neuropeptide (dark-pigmentotropin) from the corpora cardiaca of two plague locusts, Schistocerca gregaria and Locusta migratoria. The chromatographic isolation of this neuropeptide was monitored by using a bioassay with an albino mutant of L. migratoria. The neurohormone, consisting of 11 amino acids, is identical to [His7] corazonin, previously isolated from corpora cardiaca of another acridid without known function. The present results show that even in isolated (solitary) nymphs, [His7] corazonin induces gregarious black patterns. Its primary structure shows some similarity with the vertebrate melanophore stimulating hormone. PMID:10359842

  6. Possible roles of actin and myosin during anaphase chromosome movements in locust spermatocytes.

    PubMed

    Fabian, Lacramioara; Forer, Arthur

    2007-01-01

    We tested whether the mechanisms of chromosome movement during anaphase in locust (Locusta migratoria L.) spermatocytes might be similar to those described for crane-fly spermatocytes. Actin and myosin have been implicated in anaphase chromosome movements in crane-fly spermatocytes, as indicated by the effects of inhibitors and by the localisations of actin and myosin in spindles. In this study, we tested whether locust spermatocyte spindles also utilise actin and myosin, and whether actin is involved in microtubule flux. Living locust spermatocytes were treated with inhibitors of actin (latrunculin B and cytochalasin D), myosin (BDM), or myosin phosphorylation (Y-27632 and ML-7). We added drugs (individually) during anaphase. Actin inhibitors alter anaphase: chromosomes either completely stop moving, slow, or sometimes accelerate. The myosin inhibitor, BDM, also alters anaphase: in most cases, the chromosomes drastically slow or stop. ML-7, an inhibitor of MLCK, causes chromosomes to stop, slow, or sometimes accelerate, similar to actin inhibitors. Y-27632, an inhibitor of Rho-kinase, drastically slows or stops anaphase chromosome movements. The effects of the drugs on anaphase movement are reversible: most of the half-bivalents resumed movement at normal speed after these drugs were washed out. Actin and myosin were present in the spindles in locations consistent with their possible involvement in force production. Microtubule flux along kinetochore fibres is an actin-dependent process, since LatB completely removes or drastically reduces the gap in microtubule acetylation at the kinetochore. These results suggest that actin and myosin are involved in anaphase chromosome movements in locust spermatocytes. PMID:17922265

  7. Dynamic model and performance analysis of landing buffer for bionic locust mechanism

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Sheng; Zhang, Zi-Qiang; Chen, Ke-Wei

    2016-06-01

    The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is proposed. Given the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance, and it establishes a theoretical basis for studies and engineering applications.

  8. 77 FR 66541 - Safety Zone; Alliance Road Bridge Demolition; Black Warrior River, Locust Fork; Birmingham, AL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-06

    ...The Coast Guard is establishing a temporary safety zone for a portion of the Locust Fork to the Black Warrior River, Birmingham, AL. This action is necessary for the protection of persons and vessels on navigable waters during the demolition of the Alliance Road Bridge (Co. Rd. 61). Entry into, transiting or anchoring in this zone is prohibited to all vessels, mariners, and persons unless......

  9. Dynamic model and performance analysis of landing buffer for bionic locust mechanism

    NASA Astrophysics Data System (ADS)

    Chen, Dian-Sheng; Zhang, Zi-Qiang; Chen, Ke-Wei

    2015-10-01

    The landing buffer is an important problem in the research on bionic locust jumping robots, and the different modes of landing and buffering can affect the dynamic performance of the buffering process significantly. Based on an experimental observation, the different modes of landing and buffering are determined, which include the different numbers of landing legs and different motion modes of legs in the buffering process. Then a bionic locust mechanism is established, and the springs are used to replace the leg muscles to achieve a buffering effect. To reveal the dynamic performance in the buffering process of the bionic locust mechanism, a dynamic model is established with different modes of landing and buffering. In particular, to analyze the buffering process conveniently, an equivalent vibration dynamic model of the bionic locust mechanism is proposed. Given the support forces of the ground to the leg links, which can be obtained from the dynamic model, the spring forces of the legs and the impact resistance of each leg are the important parameters affecting buffering performance, and evaluation principles for buffering performance are proposed according to the aforementioned parameters. Based on the dynamic model and these evaluation principles, the buffering performances are analyzed and compared in different modes of landing and buffering on a horizontal plane and an inclined plane. The results show that the mechanism with the ends of the legs sliding can obtain a better dynamic performance. This study offers primary theories for buffering dynamics and an evaluation of landing buffer performance, and it establishes a theoretical basis for studies and engineering applications.

  10. Migratory decisions in birds: extent of genetic versus environmental control.

    PubMed

    Ogonowski, Mark S; Conway, Courtney J

    2009-08-01

    Migration is one of the most spectacular of animal behaviors and is prevalent across a broad array of taxa. In birds, we know much about the physiological basis of how birds migrate, but less about the relative contribution of genetic versus environmental factors in controlling migratory tendency. To evaluate the extent to which migratory decisions are genetically determined, we examined whether individual western burrowing owls (Athene cunicularia hypugaea) change their migratory tendency from one year to the next at two sites in southern Arizona. We also evaluated the heritability of migratory decisions by using logistic regression to examine the association between the migratory tendency of burrowing owl parents and their offspring. The probability of migrating decreased with age in both sexes and adult males were less migratory than females. Individual owls sometimes changed their migratory tendency from one year to the next, but changes were one-directional: adults that were residents during winter 2004-2005 remained residents the following winter, but 47% of adults that were migrants in winter 2004-2005 became residents the following winter. We found no evidence for an association between the migratory tendency of hatch-year owls and their male or female parents. Migratory tendency of hatch-year owls did not differ between years, study sites or sexes or vary by hatching date. Experimental provision of supplemental food did not affect these relationships. All of our results suggest that heritability of migratory tendency in burrowing owls is low, and that intraspecific variation in migratory tendency is likely due to: (1) environmental factors, or (2) a combination of environmental factors and non-additive genetic variation. The fact that an individual's migratory tendency can change across years implies that widespread anthropogenic changes (i.e., climate change or changes in land use) could potentially cause widespread changes in the migratory tendency of

  11. Long-term effects of the trehalase inhibitor trehazolin on trehalase activity in locust flight muscle.

    PubMed

    Wegener, Gerhard; Macho, Claudia; Schlöder, Paul; Kamp, Günter; Ando, Osamu

    2010-11-15

    Trehalase (EC 3.2.1.28) hydrolyzes the main haemolymph sugar of insects, trehalose, into the essential cellular substrate glucose. Trehalase in locust flight muscle is bound to membranes that appear in the microsomal fraction upon tissue fractionation, but the exact location in vivo has remained elusive. Trehalase has been proposed to be regulated by a novel type of activity control that is based on the reversible transformation of a latent (inactive) form into an overt (active) form. Most trehalase activity from saline-injected controls was membrane-bound (95%) and comprised an overt form (∼25%) and a latent form (75%). Latent trehalase could be assayed only after the integrity of membranes had been destroyed. Trehazolin, a potent tight-binding inhibitor of trehalase, is confined to the extracellular space and has been used as a tool to gather information on the relationship between latent and overt trehalase. Trehazolin was injected into the haemolymph of locusts, and the trehalase activity of the flight muscle was determined at different times over a 30-day period. Total trehalase activity in locust flight muscle was markedly inhibited during the first half of the interval, but reappeared during the second half. Inhibition of the overt form preceded inhibition of the latent form, and the time course suggested a reversible precursor-product relation (cycling) between the two forms. The results support the working hypothesis that trehalase functions as an ectoenzyme, the activity of which is regulated by reversible transformation of latent into overt trehalase. PMID:21037064

  12. Disruption of the blood-brain barrier exacerbates spreading depression in the locust CNS.

    PubMed

    Spong, Kristin E; Rochon-Terry, Geneviève; Money, Tomas G A; Robertson, R Meldrum

    2014-07-01

    In response to cellular stress in the nervous system of the locust (Locusta migratoria) neural function is interrupted in association with ionic disturbances propagating throughout nervous tissue (Spreading depression; SD). The insect blood-brain barrier (BBB) plays a critical role in the regulation of ion levels within the CNS. We investigated how a disruption in barrier function by transient exposure to 3M urea affects locusts' vulnerability to disturbances in ion levels. Repetitive SD was induced by bath application of ouabain and the extracellular potassium concentration ([K(+)]o) within the metathoracic ganglion (MTG) was monitored. Urea treatment increased the susceptibility to ouabain and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels during episodes of repetitive SD. Additionally, using a within animal protocol we demonstrate that waves of SD, induced by high K(+), propagate throughout the MTG faster following disruption of the BBB. Lastly, we show that targeting the BBB of intact animals reduces their ability to sustain neural function during anoxic conditions. Our findings indicate that locust's ability to withstand stress is diminished following a reduction in barrier function likely due to an impairment of the ability of neural tissue to maintain ionic gradients. PMID:24837786

  13. Distribution of terfenadine and its metabolites in locusts studied by desorption electrospray ionization mass spectrometry imaging.

    PubMed

    Olsen, Line Rørbæk; Hansen, Steen Honoré; Janfelt, Christian

    2015-03-01

    Desorption electrospray ionization (DESI) mass spectrometry (MS) imaging was used to image locusts dosed with the antihistamine drug terfenadine. The study was conducted in order to elucidate a relatively high elimination rate of terfenadine from the locust hemolymph. In this one of the few MS imaging studies on insects, a method for cryosectioning of whole locusts was developed, and the distributions of a number of endogenous compounds are reported, including betaine and a number of amino acids and phospholipids. Terfenadine was detected in the stomach region and the intestine walls, whereas three different metabolites-terfenadine acid (fexofenadine), terfenadine glucoside, and terfenadine phosphate-were detected in significantly smaller amounts and only in the unexcreted feces in the lower part of the intestine. The use of MS/MS imaging was necessary in order to detect the metabolites. With use of DESI-MS imaging, no colocalization of the drug and the metabolites was observed, suggesting a very rapid excretion of metabolites into the feces. Additional liquid chromatography-MS investigations were performed on hemolymph and feces and showed some abundance of terfenadine and the three metabolites, although at low levels, in both the hemolymph and the feces. PMID:25404166

  14. Looming detection by identified visual interneurons during larval development of the locust Locusta migratoria.

    PubMed

    Simmons, Peter J; Sztarker, Julieta; Rind, F Claire

    2013-06-15

    Insect larvae clearly react to visual stimuli, but the ability of any visual neuron in a newly hatched insect to respond selectively to particular stimuli has not been directly tested. We characterised a pair of neurons in locust larvae that have been extensively studied in adults, where they are known to respond selectively to objects approaching on a collision course: the lobula giant motion detector (LGMD) and its postsynaptic partner, the descending contralateral motion detector (DCMD). Our physiological recordings of DCMD axon spikes reveal that at the time of hatching, the neurons already respond selectively to objects approaching the locust and they discriminate between stimulus approach speeds with differences in spike frequency. For a particular approaching stimulus, both the number and peak frequency of spikes increase with instar. In contrast, the number of spikes in responses to receding stimuli decreases with instar, so performance in discriminating approaching from receding stimuli improves as the locust goes through successive moults. In all instars, visual movement over one part of the visual field suppresses a response to movement over another part. Electron microscopy demonstrates that the anatomical substrate for the selective response to approaching stimuli is present in all larval instars: small neuronal processes carrying information from the eye make synapses both onto LGMD dendrites and with each other, providing pathways for lateral inhibition that shape selectivity for approaching objects. PMID:23531812

  15. The control of sets of motoneurones by local interneurones in the locust.

    PubMed Central

    Burrows, M

    1980-01-01

    1. A motoneurone innervating a muscle in a hind leg of a locust is controlled in a graded manner by many non-spiking, local interneurones. There is overlap and fractionation of control between these interneurones. Some interneurones depolarize the motoneurone over part of its range, others hyperpolarize it, whilst some do both. 2. The interneurones organize the small number of motoneurones that innervate one muscle into overlapping sets of various sizes. A motoneurone can therefore be activated individually or in particular combinations with its fellow motoneurones. 3. The motoneurones innervating two muscles of a joint are also organized into overlapping sets by many local interneurones. This permits the motoneurones to the two muscles to be activated reciprocally, together, or independently. 4. One interneurone can elicit a co-ordinated movement of one, two or even three joints in a hind leg that are components of the normal behaviour of the locust. 5. A single interneurone acting alone does not usually elicit the maximum output from one motoneurone, nor a complete piece of behaviour. A stronger contraction of a muscle and a more complete movement results from the action of groups of interneurones. 6. It is suggested that local interneurones, exerting graded control over motoneurones are a major element in the organization of motor patterns in the locust. PMID:7359394

  16. Time-varying span efficiency through the wingbeat of desert locusts

    PubMed Central

    Henningsson, Per; Bomphrey, Richard J.

    2012-01-01

    The flight performance of animals depends greatly on the efficacy with which they generate aerodynamic forces. Accordingly, maximum range, load-lifting capacity and peak accelerations during manoeuvres are all constrained by the efficiency of momentum transfer to the wake. Here, we use high-speed particle image velocimetry (1 kHz) to record flow velocities in the near wake of desert locusts (Schistocerca gregaria, Forskål). We use the measured flow fields to calculate time-varying span efficiency throughout the wing stroke cycle. The locusts are found to operate at a maximum span efficiency of 79 per cent, typically at a plateau of about 60 per cent for the majority of the downstroke, but at lower values during the upstroke. Moreover, the calculated span efficiencies are highest when the largest lift forces are being generated (90% of the total lift is generated during the plateau of span efficiency) suggesting that the combination of wing kinematics and morphology in locust flight perform most efficiently when doing the most work. PMID:22112649

  17. Relationship between desert locust, Schistocerca gregaria (Forskål), infestation, environmental factors and control measures in Gazan and Makkah Regions, Saudi Arabia.

    PubMed

    Al-Ajlan, Abdulaziz M

    2007-10-15

    Desert Locust, Schistocerca gregaria (Forskål), is one of the most important insect pests in Saudi Arabia. Cultivated crops and the range lands are heavily affected by desert locust in some regions of Saudi Arabia. The objective of this study was to determine the extent of damage by the Desert Locust, Schistocerca gregaria (Forskål) to the range lands being used for grazing range animals in Gazan and Makkah regions of Saudi Arabia. However, it is very difficult to estimate accurately the total infested areas, which were sprayed with insecticides to control upsurges, outbreaks and plagues over the last five decades. Records of Desert Locust control are kept in the National Desert Locust Control and Research Center in Jeddah. Meteorological data was obtained from the Meteorology and Environmental Protection Administration (MEPA), Saudi Arabia. The data shows that the Desert Locust infestation was associated partially with the rainfall intensity in Gazan and Makkah regions. There was found a good relationship between Desert Locust infestation (Solitary phase), temperature and the relative humidity. The locust infestation was heavy during 1986-88, 1992-95 and 1997-98 and about 1.8 million ha were treated with insecticides. Out of the total breeding/infested area, 43% was treated in winter months (October-February) and the remaining 57% was treated in spring season (March-June). The infested area was sprayed with Marshall, Carbosulfan (20%), Malathion (96%, Clorpyrifos; (48%) Fipronil (12.5%), Sumithion (100%) and Decis (12.5%). The study showed an excellent potential to determine the active locust infestation period in relation to the environmental factors for its effective control with insecticide sprays to minimize crop damage. The study highlighted the needs for further investigations in other locust infested areas with different environmental factors for planning future desert locust control programs. PMID:19093456

  18. Mature non-native black-locust (Robinia pseudoacacia L.) forest does not regain the lichen diversity of the natural forest.

    PubMed

    Nascimbene, Juri; Nimis, Pier Luigi; Benesperi, Renato

    2012-04-01

    The responses of lichens to habitat changes caused by invasive trees are poorly understood. Invasive forest trees may impact epiphytic lichens by altering both substrate and stand conditions. Previous research has demonstrated that black locust invasion, associated with intensive exploitation of native oak forests, led to dramatic shifts in lichen composition. However, it is not clear if, along with stand aging, black locust formations regain forest species. The main aim of this study was to test whether the succession of black locust stands promotes a lichen succession leading to assemblages in mature black locust stands which are similar to those of native forests. To test the influence of macro-environmental conditions, we performed the study in two bioclimatically different areas of Italy. The epiphytic lichen biota of native oak and chestnut stands was compared with that of black locust stands of different successional stages. In both regions we did not find a lichen succession in black locust stands of different age, and mature black-locust stands did not recover the diversity of epiphytic species, which are lost by the replacement of the native forests by black locust. The absence of this pattern may be caused by factors related to the management of black locust stands, and to bark features. The different bioclimatic conditions between the two study areas may explain differences in the lichen biota of native forests, while that of black locust stands tend to be similar between regions, suggesting that forest habitat changes associated with the spread of black locust could decrease lichen diversity among bioclimatically different regions. PMID:22341402

  19. Transcriptome Analysis of the Desert Locust Central Nervous System: Production and Annotation of a Schistocerca gregaria EST Database

    PubMed Central

    Badisco, Liesbeth; Huybrechts, Jurgen; Simonet, Gert; Verlinden, Heleen; Marchal, Elisabeth; Huybrechts, Roger; Schoofs, Liliane; De Loof, Arnold; Vanden Broeck, Jozef

    2011-01-01

    Background The desert locust (Schistocerca gregaria) displays a fascinating type of phenotypic plasticity, designated as ‘phase polyphenism’. Depending on environmental conditions, one genome can be translated into two highly divergent phenotypes, termed the solitarious and gregarious (swarming) phase. Although many of the underlying molecular events remain elusive, the central nervous system (CNS) is expected to play a crucial role in the phase transition process. Locusts have also proven to be interesting model organisms in a physiological and neurobiological research context. However, molecular studies in locusts are hampered by the fact that genome/transcriptome sequence information available for this branch of insects is still limited. Methodology We have generated 34,672 raw expressed sequence tags (EST) from the CNS of desert locusts in both phases. These ESTs were assembled in 12,709 unique transcript sequences and nearly 4,000 sequences were functionally annotated. Moreover, the obtained S. gregaria EST information is highly complementary to the existing orthopteran transcriptomic data. Since many novel transcripts encode neuronal signaling and signal transduction components, this paper includes an overview of these sequences. Furthermore, several transcripts being differentially represented in solitarious and gregarious locusts were retrieved from this EST database. The findings highlight the involvement of the CNS in the phase transition process and indicate that this novel annotated database may also add to the emerging knowledge of concomitant neuronal signaling and neuroplasticity events. Conclusions In summary, we met the need for novel sequence data from desert locust CNS. To our knowledge, we hereby also present the first insect EST database that is derived from the complete CNS. The obtained S. gregaria EST data constitute an important new source of information that will be instrumental in further unraveling the molecular principles of phase

  20. Overseas seed dispersal by migratory birds.

    PubMed

    Viana, Duarte S; Gangoso, Laura; Bouten, Willem; Figuerola, Jordi

    2016-01-13

    Long-distance dispersal (LDD) promotes the colonization of isolated and remote habitats, and thus it has been proposed as a mechanism for explaining the distributions of many species. Birds are key LDD vectors for many sessile organisms such as plants, yet LDD beyond local and regional scales has never been directly observed nor quantified. By sampling birds caught while in migratory flight by GPS-tracked wild falcons, we show that migratory birds transport seeds over hundreds of kilometres and mediate dispersal from mainland to oceanic islands. Up to 1.2% of birds that reached a small island of the Canary Archipelago (Alegranza) during their migration from Europe to Sub-Saharan Africa carried seeds in their guts. The billions of birds making seasonal migrations each year may then transport millions of seeds. None of the plant species transported by the birds occurs in Alegranza and most do not occur on nearby Canary Islands, providing a direct example of the importance of environmental filters in hampering successful colonization by immigrant species. The constant propagule pressure generated by these LDD events might, nevertheless, explain the colonization of some islands. Hence, migratory birds can mediate rapid range expansion or shifts of many plant taxa and determine their distribution. PMID:26740610

  1. Spatial Heterogeneity in Resource Distribution Promotes Facultative Sociality in Two Trans-Saharan Migratory Birds

    PubMed Central

    Cortés-Avizanda, Ainara; Almaraz, Pablo; Carrete, Martina; Sánchez-Zapata, José A.; Delgado, Antonio; Hiraldo, Fernando; Donázar, José A.

    2011-01-01

    Background Migrant populations must cope not only with environmental changes in different biomes, but also with the continuous constraints imposed by human-induced changes through landscape transformation and resource patchiness. Theoretical studies suggest that changes in food distribution can promote changes in the social arrangement of individuals without apparent adaptive value. Empirical research on this subject has only been performed at reduced geographical scales and/or for single species. However, the relative contribution of food patchiness and predictability, both in space and time, to abundance and sociality can vary among species, depending on their degree of flexibility. Methodology/Principal Findings By means of constrained zero-inflated Generalized Additive Models we analysed the spatial distribution of two trans-Saharan avian scavengers that breed (Europe) and winter (Africa) sympatrically, in relation to food availability. In the summering grounds, the probability of finding large numbers of both species increases close to predictable feeding sources, whereas in the wintering grounds, where food resources are widespread, we did not find such aggregation patterns, except for the black kite, which aggregated at desert locust outbreaks. The comparison of diets in both species through stable isotopes revealed that their diets overlapped during summering, but not during wintering. Conclusions/Significance Our results suggest that bird sociality at feeding grounds is closely linked to the pattern of spatial distribution and predictability of trophic resources, which are ultimately induced by human activities. Migrant species can show adaptive foraging strategies to face changing distribution of food availability in both wintering and summering quarters. Understanding these effects is a key aspect for predicting the fitness costs and population consequences of habitat transformations on the viability of endangered migratory species. PMID:21731640

  2. Synaptic activation of efferent neuromodulatory neurones in the locust Schistocerca gregaria.

    PubMed

    Baudoux, S; Burrows, M

    1998-12-01

    The segmental ganglia of the locust contain efferent neuromodulatory neurones with cell bodies at the dorsal midline and axons that supply muscles and other tissue on both sides of the body. These are the dorsal unpaired median (DUM) neurones. Intracellular recordings were made from pairs of known metathoracic efferent DUM neurones in locusts in which all nerves were intact and in isolated metathoracic ganglia. The 19 metathoracic, efferent DUM neurones were identified according to the nerve roots through which their axons emerge from the ganglion. The synaptic potentials in these DUM neurones have been analysed to investigate how these neurones are activated and how their spikes are controlled. The degree of correlation between the synaptic potentials in particular pairs of neurones was quantified using a correlation analysis. This allowed the population of DUM neurones to be divided into three subsets that also map onto an anatomical grouping based on the distribution of their axons in the lateral nerves: (i) DUM1 neurones (DUMDL and DUM1b); (ii) DUM3 and DUM3,4 neurones; and (iii) DUM3,4,5, DUM5b neurones and DUMETi. Individual neurones within each subset showed strong correlations between their synaptic potentials, in both intact locusts and isolated ganglia, and tended to spike at the same time. Neurones in different subsets had few synaptic potentials in common and tended to spike independently. The persistence of common synaptic potentials in neurones of the three subsets in isolated ganglia indicates that they are derived from neurones within the metathoracic ganglion. The DUM neurones that had many common synaptic potentials in a quiescent locust responded in similar ways to mechanosensory stimulation of different parts of the body. DUM3,4, 5 and DUM5 neurones gave the clearest and most consistent responses to stimulation of mechanoreceptors on either hind leg. DUM3 and DUM3, 4 neurones responded variably, but usually with a hyperpolarisation. DUM1

  3. Immune responses of locusts to challenge with the pathogenic fungus Metarhizium or high doses of laminarin.

    PubMed

    Mullen, Lisa M; Goldsworthy, Graham J

    2006-04-01

    Two isolates of Metarhizium anisopliae var acridum were tested for their effects on the locust immune system and for comparison with the effects of challenge by injection with laminarin. Isolate IMI 330189 (referred to hereafter as Met 189) is highly pathogenic whether applied topically as conidia or injected as blastospores. However, isolate ARSEF 728 (referred to hereafter as Met 728) is pathogenic only when injected as blastospores, suggesting that the lack of pathogenicity of topically applied conidia from this isolate is due to a failure to penetrate the insect cuticle and gain access to the haemocoel. After topical application of conidia from Met 189, no activation of prophenoloxidase is detected, but injection of blastospores from Met 189 brings about a transient increase in phenoloxidase activity in the haemolymph in both adult locusts and 5th instar nymphs, although this does not prevent fungal-induced mortality. Co-injection of adipokinetic hormone-I (AKH-I) with blastospores prolongs the activation of prophenoloxidase in the haemolymph of adult locusts, and enhances it in nymphs. It is argued that the lack of activation of prophenoloxidase in nymphs shown previously (Mullen, L., Goldsworthy, G., 2003. Changes in lipophorins are related to the activation of phenoloxidase in the haemolymph of Locusta migratoria in response to injection of immunogens. Insect Biochemistry and Molecular Biology 33, 661-670), reflects differences in the sensitivity of the immune system between adults and nymphs rather than distinct qualitative differences, and this is confirmed in this study by the demonstration that doses of laminarin higher than those used previously (>or=100 microg) do activate the prophenoloxidase cascade in 5th instar nymphs. Nodules are formed in locusts of all ages in response to fungal infection or injection of laminarin, although there is wide variation in the number, size and distribution of nodules formed. During the examination of 5th instar nymphs

  4. Escaping peril: perceived predation risk affects migratory propensity

    PubMed Central

    Hulthén, Kaj; Chapman, Ben B.; Nilsson, P. Anders; Vinterstare, Jerker; Hansson, Lars-Anders; Skov, Christian; Brodersen, Jakob; Baktoft, Henrik; Brönmark, Christer

    2015-01-01

    Although migratory plasticity is increasingly documented, the ecological drivers of plasticity are not well understood. Predation risk can influence migratory dynamics, but whether seasonal migrants can adjust their migratory behaviour according to perceived risk is unknown. We used electronic tags to record the migration of individual roach (Rutilus rutilus), a partially migratory fish, in the wild following exposure to manipulation of direct (predator presence/absence) and indirect (high/low roach density) perceived predation risk in experimental mesocosms. Following exposure, we released fish in their lake summer habitat and monitored individual migration to connected streams over an entire season. Individuals exposed to increased perceived direct predation risk (i.e. a live predator) showed a higher migratory propensity but no change in migratory timing, while indirect risk (i.e. roach density) affected timing but not propensity showing that elevated risk carried over to alter migratory behaviour in the wild. Our key finding demonstrates predator-driven migratory plasticity, highlighting the powerful role of predation risk for migratory decision-making and dynamics. PMID:26311158

  5. 75 FR 48723 - Meeting Announcement: Neotropical Migratory Bird Conservation Advisory Group

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-11

    ... Fish and Wildlife Service Meeting Announcement: Neotropical Migratory Bird Conservation Advisory Group... the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will meet in.... SUPPLEMENTARY INFORMATION: Recognizing the importance of conserving migratory birds, the U.S. Congress...

  6. 76 FR 54675 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ...This rule prescribes special early-season migratory bird hunting regulations for certain tribes on Federal Indian reservations, off-reservation trust lands, and ceded lands. This rule responds to tribal requests for U.S. Fish and Wildlife Service (hereinafter Service or we) recognition of tribal authority to regulate hunting under established guidelines. This rule allows the establishment of......

  7. 75 FR 47681 - Migratory Bird Hunting; Proposed Migratory Bird Hunting Regulations on Certain Federal Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-06

    ... Service, (703) 358-1714. SUPPLEMENTARY INFORMATION: In the May 13, 2010, Federal Register (75 FR 27144... Register (50 FR 23467). In this supplemental proposed rule, we propose special migratory bird hunting... regulations were published in the Federal Register on July 29, 2010 (75 FR 44856); early-season...

  8. 77 FR 54451 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ...This rule prescribes special early-season migratory bird hunting regulations for certain tribes on Federal Indian reservations, off-reservation trust lands, and ceded lands. This rule responds to tribal requests for U.S. Fish and Wildlife Service (hereinafter Service or we) recognition of tribal authority to regulate hunting under established guidelines. This rule allows the establishment of......

  9. A SCHOOL AND HEALTH RECORD TRANSFER SYSTEM FOR MIGRATORY CHILDREN OF MIGRATORY AGRICULTURAL WORKERS (CALIFORNIA).

    ERIC Educational Resources Information Center

    California State Dept. of Education, Sacramento.

    THE CALIFORNIA STATE DEPARTMENT OF EDUCATION HAS ADOPTED A UNIFORM TRANSFER SYSTEM FOR CHILDREN OF MIGRATORY AGRICULTURAL WORKERS. EACH SCHOOL DISTRICT ENROLLING MIGRANT CHILDREN MUST COMPLETE A STANDARDIZED FORM FOR EACH MIGRANT CHILD AND FORWARD IT WITH THE PUPIL WHEN HE WITHDRAWS FROM SCHOOL. A COPY ALSO MUST BE FORWARDED TO THE STATE…

  10. 75 FR 58249 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... in the Federal Register (75 FR 27144) a proposal to amend 50 CFR part 20. The proposal provided a... FR 32872) a second document providing supplemental proposals for early- and late-season migratory... in the Federal Register (75 FR 44856) a third document specifically dealing with the...

  11. 75 FR 53773 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-01

    ..., 2010, Federal Register (75 FR 47682), we proposed special migratory bird hunting regulations for the..., Federal Register (50 FR 23467). The guidelines respond to Tribal requests for Service recognition of their... the May 13, 2010, Federal Register (75 FR 27144), we requested that Tribes desiring special...

  12. 78 FR 11988 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ... Federal Register on August 16, 2002 (67 FR 53511) and most recently on March 26, 2012 (77 FR 17353... (77 FR 23094), to amend 50 CFR part 20. While that proposed rule dealt primarily with the regulatory... published in the Federal Register (77 FR 58732) a proposed rule that provided our proposed migratory...

  13. 77 FR 17353 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-26

    ... Register on August 16, 2002 (67 FR 53511) and most recently on March 29, 2011 (76 FR 17353). Recent Federal... 8, 2011 (76 FR 19876). While that proposed rule dealt primarily with the regulatory process for... FR 68264) a proposed rule that provided our proposed migratory bird subsistence harvest...

  14. 76 FR 68263 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ..., and a history, was originally addressed in the Federal Register on August 16, 2002 (67 FR 53511) and most recently on March 29, 2011 (76 FR 17353). Recent Federal Register documents, which are all final... migratory birds in Alaska in a proposed rule published in the Federal Register on April 8, 2011 (76 FR...

  15. 77 FR 58731 - Migratory Bird Subsistence Harvest in Alaska; Harvest Regulations for Migratory Birds in Alaska...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ..., and a history, was originally addressed in the Federal Register on August 16, 2002 (67 FR 53511) and most recently on March 26, 2012 (77 FR 17353). Recent Federal Register documents, which are all... migratory birds in Alaska in a proposed rule published in the Federal Register on April 17, 2012, (77...

  16. 78 FR 53217 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-28

    ... Register (78 FR 47136), we proposed special migratory bird hunting regulations for the 2013-14 hunting... (50 FR 23467). The guidelines respond to tribal requests for Service recognition of their reserved... the April 9, 2013, Federal Register (78 FR 21200), we requested that tribes desiring special...

  17. 76 FR 19875 - Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-08

    ... guidelines described in the June 4, 1985, Federal Register (50 FR 23467) to establish special migratory game... regulatory process, in the March 14, 1990, Federal Register (55 FR 9618). Regulatory Schedule for 2011-12... (67 FR 53511) a final rule that established procedures for incorporating subsistence management...

  18. 78 FR 21199 - Migratory Bird Hunting; Proposed 2013-14 Migratory Game Bird Hunting Regulations (Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-09

    ... June 4, 1985, Federal Register (50 FR 23467) to establish special migratory game bird hunting... Register (55 FR 9618). Regulatory Schedule for 2013-14 This document is the first in a series of proposed... season by indigenous inhabitants. On August 16, 2002, we published in the Federal Register (67 FR...

  19. 76 FR 36508 - Migratory Bird Hunting; Supplemental Proposals for Migratory Game Bird Hunting Regulations for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-22

    ... (76 FR 19876) a proposal to amend 50 CFR part 20. The proposal provided a background and overview of..., proposed rule (76 FR 19876): National Environmental Policy Act; Endangered Species Act; Regulatory... for Migratory Game Bird Hunting Regulations for the 2011-12 Hunting Season; Notice of Meetings...

  20. 77 FR 73608 - Atlantic Highly Migratory Species; 2006 Consolidated Highly Migratory Species Fishery Management...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-11

    ...On November 26, 2012, NMFS published a proposed rule for Amendment 5 to the 2006 Consolidated Highly Migratory Species (HMS) Fishery Management Plan (FMP) in response to several shark stock assessments that were completed from 2009 to 2012. As described in the proposed rule, NMFS is proposing measures that would reduce fishing mortality and effort in order to rebuild overfished Atlantic shark......

  1. Are Migratory Animals Superspreaders of Infection?

    PubMed

    Fritzsche McKay, Alexa; Hoye, Bethany J

    2016-08-01

    Migratory animals are simultaneously challenged by the physiological demands of long-distance movements and the need to avoid natural enemies including parasites and pathogens. The potential for animal migrations to disperse pathogens across large geographic areas has prompted a growing body of research investigating the interactions between migration and infection. However, the phenomenon of animal migration is yet to be incorporated into broader theories in disease ecology. Because migrations may expose animals to a greater number and diversity of pathogens, increase contact rates between hosts, and render them more susceptible to infection via changes to immune function, migration has the potential to generate both "superspreader species" and infection "hotspots". However, migration has also been shown to reduce transmission in some species, by facilitating parasite avoidance ("migratory escape") and weeding out infected individuals ("migratory culling"). This symposium was convened in an effort to characterize more broadly the role that animal migrations play in the dynamics of infectious disease, by integrating a range of approaches and scales across host taxa. We began with questions related to within-host processes, focusing on the consequences of nutritional constraints and strenuous movement for individual immune capability, and of parasite infection for movement capacity. We then scaled-up to between-host processes to identify what types, distances, or patterns of host movements are associated with the spread of infectious agents. Finally, we discussed landscape-scale relationships between migration and infectious disease, and how these may be altered as a result of anthropogenic changes to climate and land use. We are just beginning to scratch the surface of the interactions between infection and animal migrations; yet, with so many migrations now under threat, there is an urgent need to develop a holistic understanding of the potential for migrations to

  2. Assessing allowable take of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.

    2009-01-01

    Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be

  3. Links between worlds: Unraveling migratory connectivity

    USGS Publications Warehouse

    Webster, M.; Marra, P.P.; Haig, Susan M.; Bensch, S.; Holmes, Richard T.

    2002-01-01

    Migration is the regular seasonal movement of animals from one place to another, often from a breeding site to a nonbreeding site and back. Because the act of migration makes it difficult to follow individuals and populations year round, our understanding of the ecology and evolution of migrating organisms, particularly birds, has been severely impeded. Exciting new advances in satellite telemetry, genetic analyses and stable isotope chemistry are now making it possible to determine the population and geographical origin of individual birds. Here, we review these new approaches and consider the relevance of understanding migratory connectivity to ecological, evolutionary and conservation issues.

  4. Climate and the complexity of migratory phenology: sexes, migratory distance, and arrival distributions

    NASA Astrophysics Data System (ADS)

    Macmynowski, Dena P.; Root, Terry L.

    2007-05-01

    The intra- and inter-season complexity of bird migration has received limited attention in climatic change research. Our phenological analysis of 22 species collected in Chicago, USA, (1979 2002) evaluates the relationship between multi-scalar climate variables and differences (1) in arrival timing between sexes, (2) in arrival distributions among species, and (3) between spring and fall migration. The early migratory period for earliest arriving species (i.e., short-distance migrants) and earliest arriving individuals of a species (i.e., males) most frequently correlate with climate variables. Compared to long-distance migrant species, four times as many short-distance migrants correlate with spring temperature, while 8 of 11 (73%) of long-distance migrant species’ arrival is correlated with the North Atlantic Oscillation (NAO). While migratory phenology has been correlated with NAO in Europe, we believe that this is the first documentation of a significant association in North America. Geographically proximate conditions apparently influence migratory timing for short-distance migrants while continental-scale climate (e.g., NAO) seemingly influences the phenology of Neotropical migrants. The preponderance of climate correlations is with the early migratory period, not the median of arrival, suggesting that early spring conditions constrain the onset or rate of migration for some species. The seasonal arrival distribution provides considerable information about migratory passage beyond what is apparent from statistical analyses of phenology. A relationship between climate and fall phenology is not detected at this location. Analysis of the within-season complexity of migration, including multiple metrics of arrival, is essential to detect species’ responses to changing climate as well as evaluate the underlying biological mechanisms.

  5. 77 FR 64318 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-19

    ... maintain diversity and balance in representation among fishing regions and species; the AP SOPPs only... National Oceanic and Atmospheric Administration RIN 0648-XC292 Atlantic Highly Migratory Species; Advisory... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers...

  6. 76 FR 68164 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... maintain diversity and balance in representation among fishing regions and species; the AP Bylaws only... National Oceanic and Atmospheric Administration RIN 0648-XA777 Atlantic Highly Migratory Species; Advisory... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers...

  7. 76 FR 68162 - Atlantic Highly Migratory Species; Advisory Panel

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ... diversity and balance in representation among fishing regions and species; the AP Bylaws only dictate... National Oceanic and Atmospheric Administration RIN 0648-XA777 Atlantic Highly Migratory Species; Advisory... the Atlantic Highly Migratory Species (HMS) Advisory Panel (AP). NMFS consults with and considers...

  8. 75 FR 9281 - General Provisions; Revised List of Migratory Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... also reaffirm our determination of March 15, 2005 (70 FR 12710), that the Mute Swan (Cygnus olor... Migratory Birds (50 CFR 10.13) was last revised on April 5, 1985 (50 FR 13710). In a proposed rule published May 9, 1995 (60 FR 24686), we suggested updating the List of Migratory Birds by adding 20...

  9. Sequential oogenesis is controlled by an oviduct factor in the locusts Locusta migratoria and Schistocerca gregaria: Overcoming the doctrine that patency in follicle cells is induced by juvenile hormone.

    PubMed

    Seidelmann, Karsten; Helbing, Cornelia; Göbeler, Norman; Weinert, Heike

    2016-07-01

    In insects that lay eggs in large clutches, yolk accumulation in each of the many ovarioles is restricted to the basal (terminal) oocyte, the one closest to the lateral oviduct. All succeeding (subterminal) oocytes remain small until the terminal oocytes finished their development and were ovulated into the oviduct. The major step regulating yolk uptake by terminal oocytes is the formation of gaps between cells of the follicle layer, a process termed patency. In the migratory as well as in the desert locust, patency is induced by a Patency Inducing Factor (PIF) produced by the lateral oviducts. PIF is secreted in all regions of the lateral oviducts and interacts with the basal follicle cells via the pedicel, a fine duct that connects an ovariole with the oviduct. By this mechanism, patency is triggered in the follicle cells of the terminal oocyte only, restricting yolk accumulation to the oocytes next to ovulation. In contrast to the previous hypothesis, juvenile hormone (JH) is not necessary to induce patency, rather JH amplifies the effect of PIF. PMID:27040271

  10. A muscarinic cholinergic mechanism underlies activation of the central pattern generator for locust flight.

    PubMed

    Buhl, Edgar; Schildberger, Klaus; Stevenson, Paul A

    2008-07-01

    A central question in behavioural control is how central pattern generators (CPGs) for locomotion are activated. This paper disputes the key role generally accredited to octopamine in activating the CPG for insect flight. In deafferented locusts, fictive flight was initiated by bath application of the muscarinic agonist pilocarpine, the acetylcholine analogue carbachol, and the acetylcholinesterase blocker eserine, but not by nicotine. Furthermore, in addition to octopamine, various other amines including dopamine, tyramine and histamine all induced fictive flight, but not serotonin or the amine-precursor amino acid tyrosine. However, flight initiation was not reversibly blocked by aminergic antagonists, and was still readily elicited by both natural stimulation (wind) and pilocarpine in reserpinized, amine-depleted locusts. By contrast, the muscarinic antagonists atropine and scopolamine reversibly blocked flight initiated by wind, cholinergic agonists, octopamine, and by selective stimulation of a flight-initiating interneurone (TCG). The short delay from TCG stimulation to flight onset suggests that TCG acts directly on the flight CPG, and accordingly that TCG, or its follower cell within the flight generating circuit, is cholinergic. We conclude that acetylcholine acting via muscarinic receptors is the key neurotransmitter in the mechanism underlying the natural activation of the locust flight CPG. Amines are not essential for this, but must be considered as potential neuromodulators for facilitating flight release and tuning the motor pattern. We speculate that muscarinic activation coupled to aminergic facilitation may be a general feature of behavioural control in insects for ensuring conditional recruitment of individual motor programs in accordance with momentary adaptive requirements. PMID:18587129

  11. K+ homeostasis and central pattern generation in the metathoracic ganglion of the locust.

    PubMed

    Rodgers, Corinne I; Labrie, John D; Robertson, R Meldrum

    2009-07-01

    Stress-induced arrest of ventilatory motor pattern generation is tightly correlated with an abrupt increase in extracellular potassium concentration ([K+]o) within the metathoracic neuropil of the locust, Locusta migratoria. Na+/K+-ATPase inhibition with ouabain elicits repetitive surges of [K+]o that coincide with arrest and recovery of motor activity. Here we show that ouabain induces repetitive [K+]o events in a concentration-dependent manner. 10(-5)M, 10(-4)M, and 10(-3)M ouabain was bath-applied in semi-intact locust preparations. 10(-4)M and 10(-3)M ouabain reliably induced repetitive [K+]o events whereas 10(-5)M ouabain had no significant effect. In comparison to 10(-4)M ouabain, 10(-3)M ouabain increased the number and hastened the time to onset of repetitive [K+]o waves, prolonged [K+]o event duration, increased resting [K+]o, and diminished the absolute value of [K+]o waves. Recovery of motor patterning following [K+]o events was less likely in 10(-3)M ouabain. In addition, we show that K+ channel inhibition using TEA suppressed the onset and decreased the amplitude of ouabain-induced repetitive [K+]o waves. Our results demonstrate that ventilatory circuit function in the locust CNS is dependent on the balance between mechanisms of [K+] accumulation and [K+] clearance. We suggest that with an imbalance in favour of accumulation the system tends towards a bistable state with transitions mediated by positive feedback involving voltage-dependent K+ channels. PMID:19482133

  12. Properties and sequence of a female-specific, juvenile hormone-induced protein from locust hemolymph.

    PubMed

    Zhang, J; McCracken, A; Wyatt, G R

    1993-02-15

    In the fat body of Locusta migratoria, an RNA transcript of about 800 nucleotides has been detected that is specific to the adult female and dependent on induction by juvenile hormone (JH) or an analog. The corresponding cDNA has been cloned (lambda 21) and a 718-base pair sequence determined. It encodes a 196-amino acid polypeptide, including a signal peptide. An NH2-terminal sequence has 24 out of 28 amino acids identical with those of a previously described 19K locust hemolymph protein, but the remainder of the sequence shows no similarity. From adult female hemolymph, a 21-kDa protein, designated 21K protein, has been purified, with an NH2-terminal sequence exactly matching that deduced from clone lambda 21. This 21K protein is found only in the adult female, is dependent on induction by JH, and is assumed to represent the product of the lambda 21 gene. It shows no immunochemical cross-reaction with locust 19K protein, apolipophorin III, nor with vitellogenin (Vg). Its isoelectric point is pH 5.4; it contains some carbohydrate. 21K protein is synthesized in adult female fat body, accumulates in hemolymph, and is taken up into the developing oocytes in parallel with Vg. In locusts deprived of JH with precocene, production of 21K protein and of lambda 21-hybridizing transcripts is induced by the JH analog, methoprene, in parallel with Vg and its mRNA. Because of its sex-, stage-, and JH-dependent regulation, coordinate with Vg, the 21K protein will be valuable for analysis of gene expression. PMID:7679110

  13. Neuropeptide-degrading endopeptidase activity of locust (Schistocerca gregaria) synaptic membranes.

    PubMed

    Isaac, R E

    1988-11-01

    Locust adipokinetic hormone (AKH, pGlu-Leu-Asn-Phe-Thr-Pro-Asn-Trp-Gly-Thr-NH2) was used as the substrate to measure neuropeptide-degrading endopeptidase activity in neutral membranes from ganglia of the locust Schistocerca gregaria. Initial hydrolysis of AKH at neural pH by peptidases of washed neural membranes generated pGlu-Leu-Asn and Phe-Thr-Pro-Asn-Trp-Gly-Thr-NH2 as primary metabolites, demonstrating that degradation was initiated by cleavage of the Asn-Phe bond. Amastatin protected the C-terminal fragment from further metabolism by aminopeptidase activity without inhibiting AKH degradation. The same fragments were generated on incubation of AKH with purified pig kidney endopeptidase 24.11, and enzyme known to cleave peptide bonds that involve the amino group of hydrophobic amino acids. Phosphoramidon (10 microM), a selective inhibitor of mammalian endopeptidase 24.11, partially inhibited the endopeptidase activity of locust neural membranes. This phosphoramidon-sensitive activity was shown to enriched in a synaptic membrane preparation with around 80% of the activity being inhibited by 10 microM-phosphoramidon (IC50 = 0.2 microM). The synaptic endopeptidase was also inhibited by 1 mM-EDTA, 1 mM-1,10-phenanthroline and 1 microM-thiorphan, and the activity was maximal between pH 7.3 and 8.0. Localization of the phosphoramidon-sensitive enzyme in synaptic membranes is consistent with a physiological role for this endopeptidase in the metabolism of insect peptides at the synapse. PMID:3063256

  14. Ecdysteroid signalling components in metamorphosis and development of the desert locust, Schistocerca gregaria.

    PubMed

    Lenaerts, Cynthia; Van Wielendaele, Pieter; Peeters, Paulien; Vanden Broeck, Jozef; Marchal, Elisabeth

    2016-08-01

    The arthropod-specific hormone family of ecdysteroids plays an important role in regulating diverse physiological processes, such as moulting and metamorphosis, reproduction, diapause and innate immunity. Ecdysteroids mediate their response by binding to a heterodimeric complex of two nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). In this study we investigated the role of EcR and RXR in metamorphosis and development of the desert locust, Schistocerca gregaria. The desert locust is a voracious, phytophagous, swarming pest that can ruin crops and harvests in some of the world's poorest countries. A profound knowledge of the ecdysteroid signalling pathway can be used in the development of more target-specific insecticides to combat this harmful plague insect. Here we report an in-depth profiling study of the transcript levels of EcR and RXR, as well as its downstream response genes, in different tissues isolated throughout the last larval stage of a hemimetabolous insect, showing a clear correlation with circulating ecdysteroid titres. Using RNA interference (RNAi), the role of SgEcR/SgRXR in moulting and development was investigated. We have proven the importance of the receptor components for successful moulting of locust nymphs into the adult stage. Some SgEcR/SgRXR knockdown females were arrested in the last larval stage, and 65 % of them initiated vitellogenesis and oocyte maturation, which normally only occurs in adults. Furthermore, our results clearly indicate that at the peak of ecdysteroid synthesis, on day six of the last larval stage, knockdown of SgEcR/SgRXR is affecting the transcript levels of the Halloween genes, Spook, Shadow and Shade. PMID:27180725

  15. Expression and immunolocalisation of odorant-binding and chemosensory proteins in locusts.

    PubMed

    Jin, X; Brandazza, A; Navarrini, A; Ban, L; Zhang, S; Steinbrecht, R A; Zhang, L; Pelosi, P

    2005-05-01

    We have identified, cloned and expressed a new chemosensory protein (CSP) in the desert locust Schistocerca gregaria belonging to a third sub-class of these polypeptides. Polyclonal antibodies stained a band of 14 kDa, as expected, in the extracts of antennae and palps of the adults, but not in the 4th and 5th instars. In the related species Locusta migratoria, instead, the same antibodies cross-reacted only with a band of apparent molecular mass of 35 kDa in the extract of 1st-5th instars, but not in the adults. The recombinant protein binds the fluorescent probe N-phenyl-1-naphthylamine, but none of the compounds so far reported as pheromones for S. gregaria. The expression of the odorant-binding protein (OBP) and of CSPs of sub-classes I and II was also monitored in antennae, tarsi, palpi, wings and other organs of solitary and gregarious locusts in their nymphal and adult stages. OBP was found to be antenna specific, where it is expressed at least from the 3rd instar in both solitary and gregarious locusts. CSPs, instead, appear to be more ubiquitous, with different expression patterns, according to the sub-class. Immunocytochemistry experiments revealed that OBP is present in the sensillum lymph of sensilla trichodea and basiconica, while CSP-I and CSP-III were found in the outer sensillum lymph of sensilla chaetica and in the sub-cuticular space between epidermis and cuticle of the antenna. Sensilla chaetica on other parts of the body showed the same expression of CSP-I as those on the antenna. PMID:15928808

  16. Regulation of feeding by Neuropeptide F in the desert locust, Schistocerca gregaria.

    PubMed

    Van Wielendaele, Pieter; Dillen, Senne; Zels, Sven; Badisco, Liesbeth; Vanden Broeck, Jozef

    2013-01-01

    Our knowledge on the physiological function of the insect Neuropeptide F (NPF) mostly comes from studies in the fruit fly, Drosophila melanogaster, where NPF was shown to regulate diverse processes, such as feeding, learning and responding to stress. In the desert locust, Schistocerca gregaria, only a truncated form of the "full-length" NPF (the biologically active "trNPF") has been isolated. In this study, we investigated whether this peptide is involved in the regulation of feeding in this orthopteran species. In the S. gregaria EST-database, an NPF-precursor encoding transcript was found. Alignment with other insect NPF-precursors showed relatively highest sequence conservation within the trNPF region (and the flanking dibasic cleavage site), as compared to other regions of the NPF-precursor. Quantitative real-time RT-PCR revealed that the Schgr-NPF-precursor encoding transcript occurs throughout the central nervous system with relatively high transcript levels in the brain, optic lobes and suboesophageal ganglion. It was also detected at relatively high levels in the midgut, which suggests that the encoded peptide also functions in the digestive system. Moreover, Schgr-NPF-transcript levels were notably higher in starved animals than in animals fed ad libitum, while transcript levels were also shown to be regulated after the consumption of a meal. Injection of locust trNPF in adults stimulated food intake, while RNAi knockdown reduced food intake. Furthermore, injection of trNPF in adults stimulated weight increase, while RNAi knockdown reduced weight gain. This effect of trNPF on body weight gain may result from its stimulatory effect on food intake. Taken together, we provide clear evidence for an important role of trNPF in the regulation of feeding in the desert locust, S. gregaria. PMID:23103541

  17. Neurons without dendrites?--A novel type of neurosecretory cell in locusts.

    PubMed

    Bräunig, Peter

    2015-11-01

    Small-diameter nerves were found that are associated with the lateral peripheral nerves of the unfused abdominal ganglia of locusts. Such small nerves were observed in about 30% of all cases in Locusta migratoria, more than 60% in Schistocerca gregaria. Retrograde staining of these small nerves showed two somata in the posterior, lateral, and ventral region of an abdominal ganglion. These cells give rise to the small nerves that accompany the big lateral nerves and, on their surface, form putative neurohaemal release sites. Astonishingly the cells do not form any dendritic ramifications within the neuropile of the ganglia. PMID:26133086

  18. Dissolution Improvement of Atorvastatin Calcium using Modified Locust Bean Gum by the Solid Dispersion Technique.

    PubMed

    Panghal, Dharmila; Nagpal, Manju; Thakur, Gurjeet Singh; Arora, Sandeep

    2014-03-01

    The present research was aimed at the enhancement of the dissolution rate of atorvastatin calcium by the solid dispersion technique using modified locust bean gum. Solid dispersions (SD) using modified locust bean gum were prepared by the modified solvent evaporation method. Other mixtures were also prepared by physical mixing, co-grinding, and the kneading method. The locust bean gum was subjected to heat for modification. The prepared solid dispersions and other mixtures were evaluated for equilibrium solubility studies, content uniformity, FTIR, DSC, XRD, in vitro drug release, and in vivo pharmacodynamic studies. The equilibrium solubility was enhanced in the solid dispersions (in a drug:polymer ratio of 1:6) and other mixtures such as the co-grinding mixture (CGM) and kneading mixture (KM). Maximum dissolution rate was observed in the solid dispersion batch SD3 (i.e. 50% within 15 min) with maximum drug release after 2 h (80%) out of all solid dispersions. The co-grinding mixture also exhibited a significant enhancement in the dissolution rate among the other mixtures. FTIR studies revealed the absence of drug-polymer interaction in the solid dispersions. Minor shifts in the endothermic peaks of the DSC thermograms of SD3 and CGM indicated slight changes in drug crystallinity. XRD studies further confirmed the results of DSC and FTIR. Topological changes were observed in SEM images of SD3 and CGM. In vivo pharmacodynamic studies indicated an improved efficacy of the optimized batch SD3 as compared to the pure drug at a dose of 3 mg/kg/day. Modified locust bean gum can be a promising carrier for solubility enhancement of poorly water-soluble drugs. The lower viscosity and wetting ability of MLBG, reduction in particle size, and decreased crystallinity of the drug are responsible for the dissolution enhancement of atorvastatin. The co-grinding mixture can be a good alternative to solid dispersions prepared by modified solvent evaporation due to its ease of

  19. Allometric scaling of discontinuous gas exchange patterns in the locust Locusta migratoria throughout ontogeny.

    PubMed

    Snelling, Edward P; Matthews, Philip G D; Seymour, Roger S

    2012-10-01

    The discontinuous gas exchange cycle (DGC) is a three-phase breathing pattern displayed by many insects at rest. The pattern consists of an extended breath-hold period (closed phase), followed by a sequence of rapid gas exchange pulses (flutter phase), and then a period in which respiratory gases move freely between insect and environment (open phase). This study measured CO(2) emission in resting locusts Locusta migratoria throughout ontogeny, in normoxia (21 kPa P(O2)), hypoxia (7 kPa P(O2)) and hyperoxia (40 kPa P(O2)), to determine whether body mass and ambient O(2) affect DGC phase duration. In normoxia, mean CO(2) production rate scales with body mass (M(b); g) according to the allometric power equation , closed phase duration (C; min) scales with body mass according to the equation C=8.0M(b)(0.38±0.29), closed+flutter period (C+F; min) scales with body mass according to the equation C+F=26.6M (0.20±0.25)(b) and open phase duration (O; min) scales with body mass according to the equation O=13.3M(b) (0.23±0.18). Hypoxia results in a shorter C phase and longer O phase across all life stages, whereas hyperoxia elicits shorter C, C+F and O phases across all life stages. The tendency for larger locusts to exhibit longer C and C+F phases might arise if the positive allometric scaling of locust tracheal volume prolongs the time taken to reach the minimum O(2) and maximum CO(2) set-points that determine the duration of these respective periods, whereas an increasingly protracted O phase could reflect the additional time required for larger locusts to expel CO(2) through a relatively longer tracheal pathway. Observed changes in phase duration under hypoxia possibly serve to maximise O(2) uptake from the environment, whereas the response of the DGC to hyperoxia is difficult to explain, but could be affected by elevated levels of reactive oxygen species. PMID:22735346

  20. Migratory Birds Reinforce Local Circulation of Avian Influenza Viruses

    PubMed Central

    Vuong, Oanh; Bestebroer, Theo; Lexmond, Pascal; Klaassen, Marcel; Fouchier, Ron A. M.

    2014-01-01

    Migratory and resident hosts have been hypothesized to fulfil distinct roles in infectious disease dynamics. However, the contribution of resident and migratory hosts to wildlife infectious disease epidemiology, including that of low pathogenic avian influenza virus (LPAIV) in wild birds, has largely remained unstudied. During an autumn H3 LPAIV epizootic in free-living mallards (Anas platyrhynchos) — a partially migratory species — we identified resident and migratory host populations using stable hydrogen isotope analysis of flight feathers. We investigated the role of migratory and resident hosts separately in the introduction and maintenance of H3 LPAIV during the epizootic. To test this we analysed (i) H3 virus kinship, (ii) temporal patterns in H3 virus prevalence and shedding and (iii) H3-specific antibody prevalence in relation to host migratory strategy. We demonstrate that the H3 LPAIV strain causing the epizootic most likely originated from a single introduction, followed by local clonal expansion. The H3 LPAIV strain was genetically unrelated to H3 LPAIV detected both before and after the epizootic at the study site. During the LPAIV epizootic, migratory mallards were more often infected with H3 LPAIV than residents. Low titres of H3-specific antibodies were detected in only a few residents and migrants. Our results suggest that in this LPAIV epizootic, a single H3 virus was present in resident mallards prior to arrival of migratory mallards followed by a period of virus amplification, importantly associated with the influx of migratory mallards. Thus migrants are suggested to act as local amplifiers rather than the often suggested role as vectors importing novel strains from afar. Our study exemplifies that a multifaceted interdisciplinary approach offers promising opportunities to elucidate the role of migratory and resident hosts in infectious disease dynamics in wildlife. PMID:25391154

  1. Responses to alternative rainfall regimes and antipoaching in a migratory system.

    PubMed

    Holdo, Ricardo M; Galvin, Kathleen A; Knapp, Eli; Polasky, Stephen; Hilborn, Ray; Holt, Robert D

    2010-03-01

    Migratory ungulates may be particularly vulnerable to the challenges imposed by growing human populations and climate change. These species depend on vast areas to sustain their migratory behavior, and in many cases come into frequent contact with human populations outside protected areas. They may also act as spatial coupling agents allowing feedbacks between ecological systems and local economies, particularly in the agropastoral subsistence economies found in the African savanna biome. We used HUMENTS, a spatially realistic socioecological model of the Greater Serengeti Ecosystem in East Africa, to explore the potential impacts of changing climate and poaching on the migratory wildebeest (Connochaetes taurinus) population, the fire regime, and habitat structure in the ecosystem, as well as changes in the size and economic activities of the human population outside the protected area. Unlike earlier models, the HUMENTS model predicted only moderate declines in the wildebeest population associated with an increasing human population over the next century, with a gradual expansion of agriculture, more poaching, and increases in fire frequency and reduced tree density. Changes in rainfall were predicted to have strong asymmetric effects on the size and economic activity of the human population and on livestock, and more moderate effects on wildlife and other ecological indicators. Conversely, antipoaching had a stronger effect on the ecological portion of the system because of its effect on wildebeest (and therefore on fire and habitat structure), and a weaker effect on the socioeconomic component, except in areas directly adjacent to the protected-area boundary, which were affected by crop-raiding and the availability of wildlife as a source of income. The results highlight the strong direct and indirect effects of rainfall on the various components of socioecological systems in semiarid environments, and the key role of mobile wildlife populations as agents of

  2. Effects of a methanolic extract of the plant Haplophyllum tuberculatum and of teflubenzuron on female reproduction in the migratory locust, Locusta migratoria (Orthoptera: Oedipodinae).

    PubMed

    Acheuk, Fatma; Cusson, Michel; Doumandji-Mitiche, Bahia

    2012-03-01

    The effects of a methanolic extract of the plant Haplophyllum tuberculatum (ME-Ht) and of teflubenzuron (TFB) were compared on several reproductive variables and ecdysteroid titers in the females of Locusta migratoria. The test products were administered orally to newly emerged females at doses of 1500 (ME-Ht) and 10μg/female (TFB). The methanolic extract and TFB had comparable effects on several of the variables examined. Both significantly delayed the first oviposition and reduced fecundity and fertility. ME-Ht and TFB also displayed similar effects on ovarian growth, vitellogenesis and ecdysteroid titers. Both treatments induced a drop in hemolymph protein levels as well as a reduction in vitellogenin uptake by oocytes. This delay in oogenesis was accompanied by a resorption of terminal oocytes. However, whereas TFB completely blocked egg hatch, ME-Ht only had a modest inhibitory effect on this variable. Hemolymph and ovarian ecdysteroid titers, as measured by radioimmunoassay, were similar and low in both control and treated females, except for a peak observed only in control females at the end of vitellogenesis. We discuss the functional significance of the observed effects in the context of the putative modes of action of the methanolic plant extract and TFB. PMID:22206884

  3. Discontinuous gas-exchange cycle characteristics are differentially affected by hydration state and energy metabolism in gregarious and solitary desert locusts.

    PubMed

    Talal, Stav; Ayali, Amir; Gefen, Eran

    2015-12-01

    The termination of discontinuous gas exchange cycles (DGCs) in severely dehydrated insects casts doubt on the generality of the hygric hypothesis, which posits that DGCs evolved as a water conservation mechanism. We followed DGC characteristics in the two density-dependent phases of the desert locust Schistocerca gregaria throughout exposure to an experimental treatment of combined dehydration and starvation stress, and subsequent rehydration. We hypothesized that, under stressful conditions, the more stress-resistant gregarious locusts would maintain DGCs longer than solitary locusts. However, we found no phase-specific variations in body water content, water loss rates (total and respiratory) or timing of stress-induced abolishment of DGCs. Likewise, locusts of both phases re-employed DGCs after ingesting comparable volumes of water when rehydrated. Despite comparable water management performances, the effect of exposure to stressful experimental conditions on DGC characteristics varied significantly between gregarious and solitary locusts. Interburst duration, which is affected by the ability to buffer CO2, was significantly reduced in dehydrated solitary locusts compared with gregarious locusts. Moreover, despite similar rehydration levels, only gregarious locusts recovered their initial CO2 accumulation capacity, indicating that cycle characteristics are affected by factors other than haemolymph volume. Haemolymph protein measurements and calculated respiratory exchange ratios suggest that catabolism of haemolymph proteins may contribute to a reduced haemolymph buffering capacity, and thus a compromised ability for CO2 accumulation, in solitary locusts. Nevertheless, DGC was lost at similar hydration states in the two phases, suggesting that DGCs are terminated as a result of inadequate oxygen supply to the tissues. PMID:26486365

  4. African Aesthetics

    ERIC Educational Resources Information Center

    Abiodun, Rowland

    2001-01-01

    No single traditional discipline can adequately supply answers to the many unresolved questions in African art history. Because of the aesthetic, cultural, historical, and, not infrequently, political biases, already built into the conception and development of Western art history, the discipline of art history as defined and practiced in the West…

  5. The flight apparatus of migratory and sedentary individuals of a partially migratory songbird species.

    PubMed

    Fudickar, Adam M; Partecke, Jesko

    2012-01-01

    Variations in the geometry of the external flight apparatus of birds are beneficial for different behaviors. Long-distance flight is less costly with more pointed wings and shorter tails; however these traits decrease maneuverability at low speeds. Selection has led to interspecific differences in these and other flight apparatuses in relation to migration distance. If these principles are general, how are the external flight apparatus within a partially migratory bird species shaped in which individuals either migrate or stay at their breeding grounds? We resolved this question by comparing the wing pointedness and tail length (relative to wing length) of migrant and resident European blackbirds (Turdus merula) breeding in the same population. We predicted that migrant blackbirds would have more pointed wings and shorter tails than residents. Contrary to our predictions, there were no differences between migrants and residents in either measure. Our results indicate that morphological differences between migrants and residents in this partially migratory population may be constrained. PMID:23284817

  6. 78 FR 52657 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ...This rule prescribes final early-season frameworks from which the States, Puerto Rico, and the Virgin Islands may select season dates, limits, and other options for the 2013-14 migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include seasons in Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The effect of this final rule is to facilitate......

  7. 77 FR 53117 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-30

    ...This rule prescribes final early-season frameworks from which the States, Puerto Rico, and the Virgin Islands may select season dates, limits, and other options for the 2012-13 migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include seasons in Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The effect of this final rule is to facilitate......

  8. 77 FR 58443 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ...The Fish and Wildlife Service (Service or we) prescribes final late-season frameworks from which States may select season dates, limits, and other options for the 2012-13 migratory bird hunting seasons. These late seasons include most waterfowl seasons, the earliest of which commences on September 22, 2012. The effect of this final rule is to facilitate the States' selection of hunting seasons......

  9. 78 FR 58123 - Migratory Bird Hunting; Final Frameworks for Late-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-20

    ...The Fish and Wildlife Service (Service or we) prescribes final late-season frameworks from which States may select season dates, limits, and other options for the 2013-14 migratory bird hunting seasons. These late seasons include most waterfowl seasons, the earliest of which commences on September 21, 2013. The effect of this final rule is to facilitate the States' selection of hunting seasons......

  10. 76 FR 44729 - Migratory Bird Hunting; Proposed Frameworks for Early-Season Migratory Bird Hunting Regulations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-26

    ...The U.S. Fish and Wildlife Service (hereinafter Service or we) is proposing to establish the 2011-12 early-season hunting regulations for certain migratory game birds. We annually prescribe frameworks, or outer limits, for dates and times when hunting may occur and the maximum number of birds that may be taken and possessed in early seasons. Early seasons may open as early as September 1, and......

  11. 75 FR 52873 - Migratory Bird Hunting; Final Frameworks for Early-Season Migratory Bird Hunting Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ...This rule prescribes final early-season frameworks from which the States, Puerto Rico, and the Virgin Islands may select season dates, limits, and other options for the 2010-11 migratory bird hunting seasons. Early seasons are those that generally open prior to October 1, and include seasons in Alaska, Hawaii, Puerto Rico, and the Virgin Islands. The effect of this final rule is to facilitate......

  12. Development of migratory behavior in northern white-tailed deer

    USGS Publications Warehouse

    Nelson, M.E.

    1998-01-01

    I examined the development of migratory behavior in northern white-tailed deer (Odocoileus virginianus) from 1975 to 1996 by radio-tracking adult females and their fawns. Of 40 migratory fawns with radio-collared mothers, all returned from winter ranges to their mothers' summer ranges, as did 36 fawns with unknown mothers. Of 1.5- to 3.0-year-old daughters with radio-collared mothers, 67-80% continued migrating with mothers to their traditional summer ranges. Eighty-four percent (16/19) of yearling dispersers continued migratory behavior after replacing their natal summer ranges with their dispersal ranges, and 88% (14/16) of these continued migrating to their natal winter ranges, some through at least 6.5 years of age. Twenty percent (4/20) of nonmigratory fawns dispersed as yearlings, and two became migratory between their dispersal summer ranges and new winter ranges, one through 4.9 years of age and another through 6.5 years. Seven fawns changed their movement behavior from migratory to nonmigratory or vice versa as yearlings or when older, indicating that migratory behavior is not under rigid genetic control. Thus, the adaptiveness of migration must depend upon natural selection operating upon varying capacities and propensities to learn and mimic long-distance movements and not upon migratory behavior directly.

  13. Greater migratory propensity in hosts lowers pathogen transmission and impacts.

    PubMed

    Hall, Richard J; Altizer, Sonia; Bartel, Rebecca A

    2014-09-01

    Animal migrations are spectacular and migratory species have been shown to transmit pathogens that pose risks to human health. Although migration is commonly assumed to enhance pathogen dispersal, empirical work indicates that migration can often have the opposite effect of lowering disease risk. Key to assessing disease threats to migratory species is the ability to predict how migratory behaviour influences pathogen invasion success and impacts on migratory hosts, thus motivating a mechanistic understanding of migratory host-pathogen interactions. Here, we develop a quantitative framework to examine pathogen transmission in animals that undergo two-way directed migrations between wintering and breeding grounds annually. Using the case of a pathogen transmitted during the host's breeding season, we show that a more extreme migratory strategy (defined by the time spent away from the breeding site and the total distance migrated) lowers the probability of pathogen invasion. Moreover, if migration substantially lowers the survival probability of infected animals, then populations that spend comparatively less time at the breeding site or that migrate longer distances are less vulnerable to pathogen-induced population declines. These findings provide theoretical support for two non-exclusive mechanisms proposed to explain how seasonal migration can lower infection risk: (i) escape from habitats where parasite transmission stages have accumulated and (ii) selective removal of infected hosts during strenuous journeys. Our work further suggests that barriers to long-distance movement could increase pathogen prevalence for vulnerable species, an effect already seen in some animal species undergoing anthropogenically induced migratory shifts. PMID:24460702

  14. Solubility enhancement of lovastatin by modified locust bean gum using solid dispersion techniques.

    PubMed

    Patel, Manjil; Tekade, Avinash; Gattani, Surendra; Surana, Sanjay

    2008-01-01

    The aim of the present study was to improve the solubility of poorly water soluble drug lovastatin (LS) by solid dispersion (SD) techniques using modified locust bean gum (MLBG) as a carrier. The locust bean gum (LBG) was modified by heating and there observed irreversible decrease in viscosity, whereas swelling property remains unaffected. The advantage of modification of LBG was illustrated by difference in dissolution profiles of their SD. Effect of polymer concentration and methods of preparation on solubility enhancement were studied using solubility and dissolution studies, respectively. The result of solubility study showed increase in solubility of LS with increase in concentration of MLBG. It was found that the dissolution rate of LS from its SD was dependent on the method of preparation of solid dispersions. Dissolution study revealed that the modified solvent evaporation is most convenient and effective method for solubility enhancement of poorly water soluble drug LS, among various methods of preparation of SD. The prepared SDs were characterized by differential scanning calorimetry, scanning electron microscopy, and X-ray diffraction study. In vivo study was performed by measuring 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG Co-A) reductase inhibition activity. Significant reduction in HMG Co-A reductase activity was observed in case of solid dispersions of LS than plain LS. In conclusion, MLBG could be used as a potential carrier in enhancing the dissolution rate and bioavailability of LS. PMID:19115112

  15. Molecular cloning and characterization of the allatotropin precursor and receptor in the desert locust, Schistocerca gregaria

    PubMed Central

    Lismont, Els; Vleugels, Rut; Marchal, Elisabeth; Badisco, Liesbeth; Van Wielendaele, Pieter; Lenaerts, Cynthia; Zels, Sven; Tobe, Stephen S.; Vanden Broeck, Jozef; Verlinden, Heleen

    2015-01-01

    Allatotropins (ATs) are pleiotropic neuropeptides initially isolated from the tobacco hornworm, Manduca sexta. In 2008, the first receptor for AT-like peptides (ATR) was characterized in Bombyx mori. Since then, ATRs have also been characterized in M. sexta, Tribolium castaneum, Aedes aegypti and Bombus terrestris. These receptors show sequence similarity to vertebrate orexin (ORX) receptors. When generating an EST-database of the desert locust (Schistocerca gregaria) central nervous system, we found cDNA sequences encoding the Schgr-AT precursor and a fragment of its putative receptor. This receptor cDNA has now been completed and functionally expressed in mammalian cell lines. Activation of this receptor, designated as Schgr-ATR, by Schgr-AT caused an increase in intracellular calcium ions, as well as cyclic AMP (cAMP), with an EC50 value in the nanomolar range. In addition, the transcript distribution of both the Schgr-AT precursor and Schgr-ATR was investigated by means of quantitative real-time PCR. Moreover, we found more evidence for the myotropic and allatostimulatory actions of Schgr-AT in the desert locust. These data are discussed and situated in a broader context by comparison with literature data on AT and ATR in insects. PMID:25814925

  16. Structural Organization of the Presynaptic Density at Identified Synapses in the Locust Central Nervous System

    PubMed Central

    Leitinger, Gerd; Masich, Sergej; Neumüller, Josef; Pabst, Maria Anna; Pavelka, Margit; Rind, F Claire; Shupliakov, Oleg; Simmons, Peter J; Kolb, Dagmar

    2012-01-01

    In a synaptic active zone, vesicles aggregate around a densely staining structure called the presynaptic density. We focus on its three-dimensional architecture and a major molecular component in the locust. We used electron tomography to study the presynaptic density in synapses made in the brain by identified second-order neuron of the ocelli. Here, vesicles close to the active zone are organized in two rows on either side of the presynaptic density, a level of organization not previously reported in insect central synapses. The row of vesicles that is closest to the density's base includes vesicles docked with the presynaptic membrane and thus presumably ready for release, whereas the outer row of vesicles does not include any that are docked. We show that a locust ortholog of the Drosophila protein Bruchpilot is localized to the presynaptic density, both in the ocellar pathway and compound eye visual neurons. An antibody recognizing the C-terminus of the Bruchpilot ortholog selectively labels filamentous extensions of the presynaptic density that reach out toward vesicles. Previous studies on Bruchpilot have focused on its role in neuromuscular junctions in Drosophila, and our study shows it is also a major functional component of presynaptic densities in the central nervous system of an evolutionarily distant insect. Our study thus reveals Bruchpilot executes similar functions in synapses that can sustain transmission of small graded potentials as well as those relaying large, spike-evoked signals. J. Comp. Neurol. 520:384–400, 2012. © 2011 Wiley Periodicals, Inc. PMID:21826661

  17. Neuropathological effect of dimethyl disulfide on neurons of the desert locust Schistocerca gregaria.

    PubMed

    Essawy, Amina E; Gaaboub, Ibrahim A; Abdel-Moneim, Ashraf M; El-Sayed, Soad A

    2015-05-01

    Botanical insecticides have introduced a new concept in insecticide research. In response to insect attacks, some plants can release volatile compounds that alter insect metabolism and nervous system activity. In the present study, changes in the electrical activity of chemoreceptors and alteration of the fine structure of metathoracic ganglia of desert locust were examined after acute exposure to dimethyl disulfide (DMDS), a sulfur compound released from Allium porrum. Animals were exposed to 1/4 LC50 of DMDS (0.375 μl/L air) and electrophysiological and electron-microscopical studies were carried out. Application of DMDS showed an increase in the activity of deterrent cells present in tarsal chemosensilla of locust. On the other hand, evident degenerative changes in the neurons, neuroglia, neuropile and synaptic vesicles were observed in the metathoracic ganglia of DMDS-treated animals. These findings revealed that pest control using DMDS might be feasible and future work is highly recommended in this respect. PMID:23377118

  18. Locust cellular defense against infections: sites of pathogen clearance and hemocyte proliferation.

    PubMed

    Duressa, Tewodros Firdissa; Vanlaer, Ria; Huybrechts, Roger

    2015-01-01

    The locust cellular defense is mediated by hemocytes and hematopoietic tissue. In Locusta migratoria, the hemocytes and hematopoietic tissue mutually assist each other in clearing invading pathogens from circulation. A β-1, 3-glucan infection induces nodule formation and apoptotic, TUNEL positive, cells in the hematopoietic tissue and massive loss of hemocytes in the circulation, calling for instant proliferation of hemocytes and hematopoietic tissue cells to assure continued host cellular defense. As the locust hematopoietic tissue persists at the adult stage, it was originally designated as being the major source for the replenishment process. Revisiting post infection hemocyte proliferation, using immunofluorescence based tests for DNA synthesis and mitosis, evidenced the lack of β-1, 3-glucan induced cell proliferation in the hematopoietic tissue. Instead these tests identified the circulating hemocytes as the major source for hemocyte replenishment in the circulation. The hematopoietic tissue, however, undergoes a continuous, slow and infection independent regeneration, thereby accumulating potential phagocytes despite infection, and might serve a prophylactic role in containing pathogens in this swarming insect. PMID:25281274

  19. Differential activation of serotonergic neurons during short- and long-term gregarization of desert locusts.

    PubMed

    Rogers, Stephen M; Ott, Swidbert R

    2015-02-01

    Serotonin is a neurochemical with evolutionarily conserved roles in orchestrating nervous system function and behavioural plasticity. A dramatic example is the rapid transformation of desert locusts from cryptic asocial animals into gregarious crop pests that occurs when drought forces them to accumulate on dwindling resources, triggering a profound alteration of behaviour within just a few hours. The onset of crowding induces a surge in serotonin within their thoracic ganglia that is sufficient and necessary to induce the switch from solitarious to gregarious behaviour. To identify the neurons responsible, we have analysed how acute exposure to three gregarizing stimuli--crowding, touching the hind legs or seeing and smelling other locusts--and prolonged group living affect the expression of serotonin in individual neurons in the thoracic ganglia. Quantitative analysis of cell body immunofluorescence revealed three classes of neurons with distinct expressional responses. All ganglia contained neurons that responded to multiple gregarizing stimuli with increased expression. A second class showed increased expression only in response to intense visual and olfactory stimuli from conspecifics. Prolonged group living affected a third and entirely different set of neurons, revealing a two-tiered role of the serotonergic system as both initiator and substrate of socially induced plasticity. This demonstrates the critical importance of ontogenetic time for understanding the function of serotonin in the reorganization of behaviour. PMID:25520357

  20. In vitro and in vivo effects of formamidines in locust (Locusta migratoria migratorioides).

    PubMed

    Hiripi, L; Nagy, L; Hollingworth, R M

    1999-01-01

    In vivo and in vitro experiments were used to study the effects of formamidines in the locust, Locusta migratoria migratorioides. In vivo the lethal and the antifeeding effects, in vitro the inhibition of the binding of a selective 3H-ligand to the receptors of octopamine, tyramine, dopamine, serotonin and gamma-amino butiric acid were studied. We have demonstrated that demethylchlordimeform is specific agonist to octopamine receptor, having high affinity to octopamine receptor, a moderate affinitiy to tyramine receptor and a low affinity to dopamine, serotonin and to gamma-amino butiric acid receptors. The demethylated chlordimeform analogoues, demethylchlordimeform and didemethylchlordimeform have higher affinity to the octopamine receptor than the parent compound. The formamidines had a toxic and an antifeeding effects when injected into the locust. The half lethal doses (LD50) and the feeding inhibition were correlated with the affinity of the compounds (Ki). The ring substitutions of the mulecule have alterated the both affinity and in vivo effect of the compounds. The most effective ring substitution pattern is 2,4-disubstitution with a combination of methyl groups or halogens. Our results suggest that the lethal effect of formamidines is mediated through the octopamine receptor. PMID:10574431

  1. Receptive fields of locust brain neurons are matched to polarization patterns of the sky.

    PubMed

    Bech, Miklós; Homberg, Uwe; Pfeiffer, Keram

    2014-09-22

    Many animals, including insects, are able to use celestial cues as a reference for spatial orientation and long-distance navigation [1]. In addition to direct sunlight, the chromatic gradient of the sky and its polarization pattern are suited to serve as orientation cues [2-5]. Atmospheric scattering of sunlight causes a regular pattern of E vectors in the sky, which are arranged along concentric circles around the sun [5, 6]. Although certain insects rely predominantly on sky polarization for spatial orientation [7], it has been argued that detection of celestial E vector orientation may not suffice to differentiate between solar and antisolar directions [8, 9]. We show here that polarization-sensitive (POL) neurons in the brain of the desert locust Schistocerca gregaria can overcome this ambiguity. Extracellular recordings from POL units in the central complex and lateral accessory lobes revealed E vector tunings arranged in concentric circles within large receptive fields, matching the sky polarization pattern at certain solar positions. Modeling of neuronal responses under an idealized sky polarization pattern (Rayleigh sky) suggests that these "matched filter" properties allow locusts to unambiguously determine the solar azimuth by relying solely on the sky polarization pattern for compass navigation. PMID:25201687

  2. Polarization-sensitive descending neurons in the locust: connecting the brain to thoracic ganglia.

    PubMed

    Träger, Ulrike; Homberg, Uwe

    2011-02-01

    Many animal species, in particular insects, exploit the E-vector pattern of the blue sky for sun compass navigation. Like other insects, locusts detect dorsal polarized light via photoreceptors in a specialized dorsal rim area of the compound eye. Polarized light information is transmitted through several processing stages to the central complex, a brain area involved in the control of goal-directed orientation behavior. To investigate how polarized light information is transmitted to thoracic motor circuits, we studied the responses of locust descending neurons to polarized light. Three sets of polarization-sensitive descending neurons were characterized through intracellular recordings from axonal fibers in the neck connectives combined with single-cell dye injections. Two descending neurons from the brain, one with ipsilaterally and the second with contralaterally descending axon, are likely to bridge the gap between polarization-sensitive neurons in the brain and thoracic motor centers. In both neurons, E-vector tuning changed linearly with daytime, suggesting that they signal time-compensated spatial directions, an important prerequisite for navigation using celestial signals. The third type connects the suboesophageal ganglion with the prothoracic ganglion. It showed no evidence for time compensation in E-vector tuning and might play a role in flight stabilization and control of head movements. PMID:21307260

  3. Extra Molting and Selection on Nymphal Growth in the Desert Locust

    PubMed Central

    Piou, Cyril; Jourdan-Pineau, Hélène; Pagès, Christine; Blondin, Laurence; Chapuis, Marie-Pierre

    2016-01-01

    In insects, extra-molting has been viewed as a compensatory mechanism for nymphal growth that contributes to optimize body weight for successful reproduction. However, little is known on the capacity of extra-molting to evolve in natural populations, which limits our understanding of how selection acts on nymphal growth. We used a multi-generational pedigree, individual monitoring and quantitative genetics models to investigate the evolution of extra-molting and its impact on nymphal growth in a solitarious population of the desert locust, Schistocerca gregaria. Growth compensation via extra-molting was observed for 46% of the females, whose adult weight exceeded by 4% that of other females, at a cost of a 22% longer development time. We found a null heritability for body weight threshold only, and the highest and a strongly female-biased heritability for extra molting. Our genetic estimates show that (1) directional selection can act on growth rate, development time and extra-molting to optimize body weight threshold, the target of stabilizing selection, (2) extra-molting can evolve in natural populations, and (3) a genetic conflict, due to sexually antagonistic selection on extra-molting, might prevent its fixation. Finally, we discuss how antagonistic selection between solitarious and gregarious environments and/or genetic correlations between growth and phase traits might also impact the evolution of extra-molting in locusts. PMID:27227885

  4. A look into the cockpit of the developing locust: looming detectors and predator avoidance.

    PubMed

    Sztarker, Julieta; Rind, F Claire

    2014-11-01

    For many animals, the visual detection of looming stimuli is crucial at any stage of their lives. For example, human babies of only 6 days old display evasive responses to looming stimuli (Bower et al. [1971]: Percept Psychophys 9: 193-196). This means the neuronal pathways involved in looming detection should mature early in life. Locusts have been used extensively to examine the neural circuits and mechanisms involved in sensing looming stimuli and triggering visually evoked evasive actions, making them ideal subjects in which to investigate the development of looming sensitivity. Two lobula giant movement detectors (LGMD) neurons have been identified in the lobula region of the locust visual system: the LGMD1 neuron responds selectively to looming stimuli and provides information that contributes to evasive responses such as jumping and emergency glides. The LGMD2 responds to looming stimuli and shares many response properties with the LGMD1. Both neurons have only been described in the adult. In this study, we describe a practical method combining classical staining techniques and 3D neuronal reconstructions that can be used, even in small insects, to reveal detailed anatomy of individual neurons. We have used it to analyze the anatomy of the fan-shaped dendritic tree of the LGMD1 and the LGMD2 neurons in all stages of the post-embryonic development of Locusta migratoria. We also analyze changes seen during the ontogeny of escape behaviors triggered by looming stimuli, specially the hiding response. PMID:24753464

  5. Collision-avoidance behaviors of minimally restrained flying locusts to looming stimuli

    PubMed Central

    Chan, R. WM.; Gabbiani, F.

    2013-01-01

    SUMMARY Visually guided collision avoidance is of paramount importance in flight, for instance to allow escape from potential predators. Yet, little is known about the types of collision-avoidance behaviors that may be generated by flying animals in response to an impending visual threat. We studied the behavior of minimally restrained locusts flying in a wind tunnel as they were subjected to looming stimuli presented to the side of the animal, simulating the approach of an object on a collision course. Using high-speed movie recordings, we observed a wide variety of collision-avoidance behaviors including climbs and dives away from – but also towards – the stimulus. In a more restrained setting, we were able to relate kinematic parameters of the flapping wings with yaw changes in the trajectory of the animal. Asymmetric wing flapping was most strongly correlated with changes in yaw, but we also observed a substantial effect of wing deformations. Additionally, the effect of wing deformations on yaw was relatively independent of that of wing asymmetries. Thus, flying locusts exhibit a rich range of collision-avoidance behaviors that depend on several distinct aerodynamic characteristics of wing flapping flight. PMID:23364572

  6. Responses of efferent octopaminergic thoracic unpaired median neurons in the locust to visual and mechanosensory signals.

    PubMed

    Field, Laurence H; Duch, Carsten; Pflüger, Hans-Joachim

    2008-01-01

    Insect thoracic ganglia contain efferent octopaminergic unpaired median neurons (UM neurons) located in the midline, projecting bilaterally and modulating neuromuscular transmission, muscle contraction kinetics, sensory sensitivity and muscle metabolism. In locusts, these neurons are located dorsally or ventrally (DUM- or VUM-neurons) and divided into functionally different sub-populations activated during different motor tasks. This study addresses the responsiveness of locust thoracic DUM neurons to various sensory stimuli. Two classes of sense organs, cuticular exteroreceptor mechanosensilla (tactile hairs and campaniform sensilla), and photoreceptors (compound eyes and ocelli) elicited excitatory reflex responses. Chordotonal organ joint receptors caused no responses. The tympanal organ (Müller's organ) elicited weak excitatory responses most likely via generally increased network activity due to increased arousal. Vibratory stimuli to the hind leg subgenual organ never elicited responses. Whereas DUM neurons innervating wing muscles are not very responsive to sensory stimulation, those innervating leg and other muscles are very responsive to stimulation of exteroreceptors and hardly responsive to stimulation of proprioceptors. After cutting both cervical connectives all mechanosensory excitation is lost, even for sensory inputs from the abdomen. This suggests that, in contrast to motor neurons, the sensory inputs to octopaminergic efferent neuromodulatory cells are pre-processed in the suboesophageal ganglion. PMID:18021797

  7. Comparing watershed black locust afforestation and natural revegetation impacts on soil nitrogen on the Loess Plateau of China.

    PubMed

    Jin, Zhao; Li, Xiangru; Wang, Yunqiang; Wang, Yi; Wang, Kaibo; Cui, Buli

    2016-01-01

    This study examined a pair of neighbouring small watersheds with contrasting vegetations: artificial forestland and natural grassland. Since 1954, afforestation which mainly planted with black locust has been conducted in one of these watersheds and natural revegetation in the other. The differences in soil total N, nitrate, ammonium, foliar litterfall δ(15)N and dual stable isotopes of δ(15)N and δ(18)O in soil nitrate were investigated in the two ecosystems. Results showed that there was no significant difference in soil total N storage between the two ecosystems, but the black locust forestland presented higher soil nitrate than the grassland. Moreover, the foliar litterfall N content and δ(15)N of the forestland were significant higher than the grassland. These results indicate that 60 years of watershed black locust afforestation have increased soil N availability. The higher nitrate in the forestland was attributed to the biological N fixation of black locust and difference in ecosystem hydrology. The dual stable isotopes of δ(15)N and δ(18)O revealed that the two ecosystems had different sources of soil nitrate. The soil nitrate in the forestland was likely derived from soil N nitrification, while the soil nitrate in the grassland was probably derived from the legacy of NO3(-) fertiliser. PMID:27112514

  8. Synthesis and biological activity of locust AKH-I and its analogues with modifications at the threonine residues.

    PubMed

    Poulos, C; Karagiannis, K; Lee, M; Goldsworthy, G

    1994-12-01

    A convenient method of synthesis, using a combination of solid and liquid phase methodology, for locust Adipokinetic Hormone-I (AKH-I) and its analogues with modifications at the threonine residues are reported. The N-terminal nonapeptide acid of AKH-I is synthesized in the solid phase using the 2-chlorotrityl chloride resin and the Fmoc/t-Bu strategy. Quantitative cleavage of the nonapeptide acid from the resin, with the tert-butyl type side-chain protection intact, is achieved with a mixture of acetic acid/trifluoroethanol/dichloromethane. The nonapeptide acid is then coupled in solution to the threonine derivatives, H-Thr-NH2 or H-Thr(Bzl)-NH2, with the DCC/HOBt method. The efficiency of this approach in the synthesis of AKH-I is demonstrated by the high yields and purity of the synthesized peptides. All the synthesized peptides were tested in two ways: first, in a lipid mobilization assay in locusts in vivo; and second, in a novel assay in vitro concerned with the uptake of radiolabelled acetate into locust tissue. Replacement of the hydroxyl hydrogen in Thr5 of locust AKH-I by the bulky and highly lipophilic tert-butyl group reduced the potency markedly, whereas efficacy is unaffected, but when the hydroxyl hydrogen of Thr10 in AKH-I is replaced by a benzyl group, the activity of the resulting analogue is identical to that of the natural peptide. Structure-activity relationships are discussed. PMID:7705981

  9. Individual Pause-and-Go Motion Is Instrumental to the Formation and Maintenance of Swarms of Marching Locust Nymphs

    PubMed Central

    Ariel, Gil; Ophir, Yotam; Levi, Sagi; Ben-Jacob, Eshel; Ayali, Amir

    2014-01-01

    The principal interactions leading to the emergence of order in swarms of marching locust nymphs was studied both experimentally, using small groups of marching locusts in the lab, and using computer simulations. We utilized a custom tracking algorithm to reveal fundamental animal-animal interactions leading to collective motion. Uncovering this behavior introduced a new agent-based modeling approach in which pause-and-go motion is pivotal. The behavioral and modeling findings are largely based on motion-related visual sensory inputs obtained by the individual locust. Results suggest a generic principle, in which intermittent animal motion can be considered as a sequence of individual decisions as animals repeatedly reassess their situation and decide whether or not to swarm. This interpretation implies, among other things, some generic characteristics regarding the build-up and emergence of collective order in swarms: in particular, that order and disorder are generic meta-stable states of the system, suggesting that the emergence of order is kinetic and does not necessarily require external environmental changes. This work calls for further experimental as well as theoretical investigation of the neural mechanisms underlying locust coordinative behavior. PMID:24988464

  10. Identification and Characterization of Two “Sensory Neuron Membrane Proteins” (SNMPs) of the Desert Locust, Schistocerca gregaria (Orthoptera: Acrididae)

    PubMed Central

    Jiang, Xingcong; Pregitzer, Pablo; Grosse-Wilde, Ewald; Breer, Heinz; Krieger, Jürgen

    2016-01-01

    Pheromone-responsive neurons of insects not only require specific receptors but in addition several auxiliary components, including the “sensory neuron membrane protein,” SNMP. Accordingly, SNMP is considered as a marker for neurons responding to pheromones. For the desert locust Schistocerca gregaria, it is known that the behavior, including aggregation behavior and courtship inhibition, is largely controlled by pheromones. However, little is known about pheromones, their receptors, and the pheromone-responsive cells in locusts. In this study, we have identified two SNMP subtypes, SNMP1 and SNMP2, and compared their phylogenetic relationship and primary structure motifs with SNMPs from other species. Both SNMPs were found in chemosensory tissues, especially the antennae. Employing double in situ hybridization, we identified and localized the SNMP-expressing cells in the antennae. Cells expressing SNMP1 were localized to sensilla trichodea but also to sensilla basiconica, which in locust respond to pheromones. One or a few cells express SNMP1 within the multineuron clusters from sensilla basiconica, whereas the SNMP2 subtype was expressed in cells surrounding the neuron clusters, possibly supporting cells. Based on the finding that SNMP1 is expressed in distinct neurons under chemosensory sensilla, it is conceivable that these cells may represent pheromone-responsive neurons of the desert locust. PMID:27012870

  11. Identification and Characterization of Two "Sensory Neuron Membrane Proteins" (SNMPs) of the Desert Locust, Schistocerca gregaria (Orthoptera: Acrididae).

    PubMed

    Jiang, Xingcong; Pregitzer, Pablo; Grosse-Wilde, Ewald; Breer, Heinz; Krieger, Jürgen

    2016-01-01

    Pheromone-responsive neurons of insects not only require specific receptors but in addition several auxiliary components, including the "sensory neuron membrane protein," SNMP. Accordingly, SNMP is considered as a marker for neurons responding to pheromones. For the desert locust Schistocerca gregaria, it is known that the behavior, including aggregation behavior and courtship inhibition, is largely controlled by pheromones. However, little is known about pheromones, their receptors, and the pheromone-responsive cells in locusts. In this study, we have identified two SNMP subtypes, SNMP1 and SNMP2, and compared their phylogenetic relationship and primary structure motifs with SNMPs from other species. Both SNMPs were found in chemosensory tissues, especially the antennae. Employing double in situ hybridization, we identified and localized the SNMP-expressing cells in the antennae. Cells expressing SNMP1 were localized to sensilla trichodea but also to sensilla basiconica, which in locust respond to pheromones. One or a few cells express SNMP1 within the multineuron clusters from sensilla basiconica, whereas the SNMP2 subtype was expressed in cells surrounding the neuron clusters, possibly supporting cells. Based on the finding that SNMP1 is expressed in distinct neurons under chemosensory sensilla, it is conceivable that these cells may represent pheromone-responsive neurons of the desert locust. PMID:27012870

  12. Comparing watershed black locust afforestation and natural revegetation impacts on soil nitrogen on the Loess Plateau of China

    PubMed Central

    Jin, Zhao; Li, Xiangru; Wang, Yunqiang; Wang, Yi; Wang, Kaibo; Cui, Buli

    2016-01-01

    This study examined a pair of neighbouring small watersheds with contrasting vegetations: artificial forestland and natural grassland. Since 1954, afforestation which mainly planted with black locust has been conducted in one of these watersheds and natural revegetation in the other. The differences in soil total N, nitrate, ammonium, foliar litterfall δ15N and dual stable isotopes of δ15N and δ18O in soil nitrate were investigated in the two ecosystems. Results showed that there was no significant difference in soil total N storage between the two ecosystems, but the black locust forestland presented higher soil nitrate than the grassland. Moreover, the foliar litterfall N content and δ15N of the forestland were significant higher than the grassland. These results indicate that 60 years of watershed black locust afforestation have increased soil N availability. The higher nitrate in the forestland was attributed to the biological N fixation of black locust and difference in ecosystem hydrology. The dual stable isotopes of δ15N and δ18O revealed that the two ecosystems had different sources of soil nitrate. The soil nitrate in the forestland was likely derived from soil N nitrification, while the soil nitrate in the grassland was probably derived from the legacy of NO3− fertiliser. PMID:27112514

  13. Comparing watershed black locust afforestation and natural revegetation impacts on soil nitrogen on the Loess Plateau of China

    NASA Astrophysics Data System (ADS)

    Jin, Zhao; Li, Xiangru; Wang, Yunqiang; Wang, Yi; Wang, Kaibo; Cui, Buli

    2016-04-01

    This study examined a pair of neighbouring small watersheds with contrasting vegetations: artificial forestland and natural grassland. Since 1954, afforestation which mainly planted with black locust has been conducted in one of these watersheds and natural revegetation in the other. The differences in soil total N, nitrate, ammonium, foliar litterfall δ15N and dual stable isotopes of δ15N and δ18O in soil nitrate were investigated in the two ecosystems. Results showed that there was no significant difference in soil total N storage between the two ecosystems, but the black locust forestland presented higher soil nitrate than the grassland. Moreover, the foliar litterfall N content and δ15N of the forestland were significant higher than the grassland. These results indicate that 60 years of watershed black locust afforestation have increased soil N availability. The higher nitrate in the forestland was attributed to the biological N fixation of black locust and difference in ecosystem hydrology. The dual stable isotopes of δ15N and δ18O revealed that the two ecosystems had different sources of soil nitrate. The soil nitrate in the forestland was likely derived from soil N nitrification, while the soil nitrate in the grassland was probably derived from the legacy of NO3‑ fertiliser.

  14. 76 FR 39367 - Migratory Bird Permits; Changes in the Regulations Governing Raptor Propagation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AX78 Migratory Bird Permits; Changes in the... primary responsibility for managing migratory birds. Our authority is based on the Migratory Bird Treaty... take and possession of migratory birds for many purposes. The BGEPA allows bald eagles and...

  15. Migratory double breeding in Neotropical migrant birds

    PubMed Central

    Rohwer, Sievert; Hobson, Keith A.; Rohwer, Vanya G.

    2009-01-01

    Neotropical migratory songbirds typically breed in temperate regions and then travel long distances to spend the majority of the annual cycle in tropical wintering areas. Using stable-isotope methodology, we provide quantitative evidence of dual breeding ranges for 5 species of Neotropical migrants. Each is well known to have a Neotropical winter range and a breeding range in the United States and Canada. However, after their first bout of breeding in the north, many individuals migrate hundreds to thousands of kilometers south in midsummer to breed a second time during the same summer in coastal west Mexico or Baja California Sur. They then migrate further south to their final wintering areas in the Neotropics. Our discovery of dual breeding ranges in Neotropical migrants reveals a hitherto unrealized flexibility in life-history strategies for these species and underscores that demographic models and conservation plans must consider dual breeding for these migrants. PMID:19858484

  16. Biomass production and water use of Black Locust (Robinia pseudoacacia L.) for short-rotation plantation

    NASA Astrophysics Data System (ADS)

    Mantovani, D.; Veste, M.; Freese, D.

    2012-04-01

    The early successional tree species Robinia pseudoacacia L. demonstrates a high potential for biomass production in short rotation plantations and agroforestry systems. On marginal lands and recultivated areas, often characterized by poor edaphic conditions, black locust is already successfully cropped. In southern Brandenburg (East Germany), vast areas have been exploited for lignite open cast mining and the outcome is a drastic alteration of the top soil layer and subsurface geological structure, causing a radical change of the hydrologic cycle. Soil poor in nutrient and carbon, combined with low rainfall, limits the reclamation of these areas and their use for conventional agriculture. However, promising results have been obtained by the establishment of black locust for bioenergy production. For the evaluation of the black locust growth potential in southern Brandenburg with its sandy soils and low annual mean rainfall, detailed information about the link between growth, transpiration and soil water availability are needed. Therefore, we determined the biomass-transpiration relation and formulated the equation that describes the intertwined interaction between water use and biomass production. The equation will be integrated into mathematical tools. To reduce the numerous environmental variables involved in field experiments, we grew black locust under semi-controlled environmental conditions by using wick lysimeters. The lysimeters were filled with sandy loam soil and water was supplied solely by an automatic irrigation system in relation to the volumetric soil water content (7%, 10%, and 14%). Rainfall is excluded by a light transmissive roof. Water use efficiency (WUE) at whole plant level is evaluated by the ratio between the biomass produced during the vegetation period and the cumulative daily water use. The study encompasses ecophysiological investigations of the gas exchange (H2O and CO2) on single leaves, to evaluate the influence of the stomata

  17. Estimation of biological nitrogen fixation by black locust in short-rotation forests using natural 15N abundance method

    NASA Astrophysics Data System (ADS)

    Veste, M.; Böhm, C.; Quinckenstein, A.; Freese, D.

    2012-04-01

    The importance of short rotation forests and agroforestry systems for woody biomass production for bioenergy will increase in Central Europe within the next decades. In this context, black locust (Robinia pseudoacacia) has a high growth potential especially at marginal, drought-susceptible sites such as occur in Brandenburg State (Eastern Germany). As a pioneer tree species black locust grows under a wide range of site conditions. The native range of black locust in Northern America is classified by a humid to sub-humid climate with a mean annual precipitation of 1020 to 1830 mm. In Central and Eastern Europe, this species is cultivated in a more continental climate with an annual precipitation often below 600 mm. Therefore, black locust is known to be relatively drought tolerant compared to other temperate, deciduous tree species. Because of its N2-fixation ability black locust plays generally an important role for the improvement of soil fertility. This effect is of particular interest at marginal sites in the post-mining landscapes. In order to estimate the N2-fixation potential of black locust at marginal sites leaf samples were taken from black locust trees in short rotation plantations planted between 1995 and 2007 in post-mining sites south of Cottbus (Brandenburg, NE Germany). The variation of the natural 15N abundance was measured to evaluate the biological nitrogen fixation. The nitrogen derived from the atmosphere can be calculated using a two-pool model from the quotient of the natural 15N abundances of the N2-fixing plant and the plant available soil N. Because representatively determining the plant available soil N is difficult, a non-N2-fixing reference plant growing at the same site with a similar root system and temporal N uptake pattern to the N2-fixing plant is often used. In our case we used red oak (Quercus rubra) as a reference. The average nitrogen content in the leaves of black locust ranged from 3.1% (C/N 14.8) in 15 years old trees to 3

  18. Using radar to advance migratory bird management: An interagency collaboration

    USGS Publications Warehouse

    Sojda, R.; Ruth, J.M.; Barrow, W.C.; Dawson, D.K.; Diehl, R.H.; Manville, A.; Green, M.T.; Krueper, D.J.; Johnston, S.

    2005-01-01

    Migratory birds face many changes to the landscapes they traverse and the habitats they use. Wind turbines and communications towers, which pose hazards to birds and bats in flight, are being erected across the United States and offshore. Human activities can also destroy or threaten habitats critical to birds during migratory passage, and climate change appears to be altering migratory patterns. The U.S. Fish and Wildlife Service (USFWS) and other agencies are under increasing pressure to identify and evaluate movement patterns and habitats used during migration and other times.

  19. Changes in patterns of corticosterone secretion concurrent with migratory fattening in a neotropical migratory bird.

    PubMed

    Holberton, R L

    1999-10-01

    Several studies on free-living birds have shown a change in corticosterone secretion (elevated baseline levels and a reduced corticosterone response to stress) during migration. It was not known, however, if this change was concurrent with the development of migratory condition or if it was an independent response to unknown environmental stressors experienced by the birds prior to capture. In this study, a Neotropical annual migrant, the yellow-rumped warbler (Dendroica coronata), held under controlled laboratory conditions, was used to test the Migration Modulation Hypothesis (MMH): during the migratory period migrants exhibit (1) elevated baseline corticosterone to facilitate migratory fattening and (2) a reduced corticosterone stress response, a means by which skeletal muscle needed for migration can be protected against catabolism by high levels of corticosterone. Fifteen hatching-year warblers were maintained on insect larvae and water ad libitum for 43 weeks, experiencing two transitions from a short- to long-day photoperiod to bring them into spring migratory condition. Corticosterone profiles comprising three blood samples from each individual (baseline at the time of initial disturbance and 30 and 60 min later), body mass, fat reserves, molt, and state of cloacal protuberance (males only) were measured at key intervals throughout the study. Over the entire study, mean baseline corticosterone levels were positively correlated with mean body mass, which increased predictably in response to long days. Individual baseline corticosterone was not correlated with individual body mass at any time. During periods when the birds were lean and held on short days, the corticosterone stress profiles were characterized by low initial hormone concentration followed by a significant increase in corticosterone with handling time. In response to long days, the warblers showed a significant increase in body mass and fat reserves concurrent with corticosterone stress

  20. Suppression of spreading depression-like events in locusts by inhibition of the NO/cGMP/PKG pathway.

    PubMed

    Armstrong, Gary A B; Rodgers, Corinne I; Money, Tomas G A; Robertson, R Meldrum

    2009-06-24

    Despite considerable research attention focused on mechanisms underlying neural spreading depression (SD), because of its association with important human CNS pathologies, such as stroke and migraine, little attention has been given to explaining its occurrence and regulation in invertebrates. In the locust metathoracic ganglion (MTG), an SD-like event occurs during heat and anoxia stress, which results in cessation of neuronal output for the duration of the applied stress. SD-like events were characterized by an abrupt rise in extracellular potassium ion concentration ([K(+)](o)) from a baseline concentration of approximately 8 to >30 mm, which returned to near baseline concentrations after removal of the applied stress. After return to baseline [K(+)](o), neuronal output (ventilatory motor pattern activity) from the MTG recovered. Unlike mammalian neurons, which depolarize almost completely during SD, locust neurons only partially depolarized. SD-like events in the locust CNS were suppressed by pharmacological inhibition of the nitric oxide/cyclic guanosine monophosphate/protein kinase G (NO/cGMP/PKG) pathway and were exacerbated by its activation. Also, environmental stressors such as heat and anoxia increased production of nitric oxide in the locust CNS. Finally, for the intact animal, manipulation of the pathway affected the speed of recovery from suffocation by immersion under water. We propose that SD-like events in locusts provide an adaptive mechanism for surviving extreme environmental conditions. The highly conserved nature of the NO/cGMP/PKG signaling pathway suggests that it may be involved in modulating SD in other organisms, including mammals. PMID:19553462

  1. Drosha, Dicer-1 and Argonaute-1 in the desert locust: phylogenetic analyses, transcript profiling and regulation during phase transition and feeding.

    PubMed

    Wynant, Niels; Santos, Dulce; Subramanyam, Sudheendra Hebbar; Verlinden, Heleen; Vanden Broeck, Jozef

    2015-04-01

    In this article, we identify and characterise the miRNA machinery components Drosha, Dicer-1 and Argonaute-1 of the desert locust. By means of phylogenetic analyses, we reveal important insights in the evolutionary context of these components. Our data illustrate that insect Argonaute-1 proteins form a monophyletic group with ALG-1 and ALG-2 of Caenorhabditis elegans and with the four (non-Piwi) Argonaute proteins present in humans. On the other hand, humans apparently lack clear homologues of the insect Argonaute-2 proteins. In addition, we demonstrate that drosha, dicer-1 and argonaute-1 display wide transcript tissue-distribution in adult desert locusts, and that during locust phase transition and feeding of starved locusts the expression levels of the miRNA pathway are regulated at the transcript level. PMID:25746231

  2. Tracking Migratory Animals: Going Online for Environmental Education.

    ERIC Educational Resources Information Center

    Coulter, Bob

    1997-01-01

    Describes a project in which students pick a migratory animal and track it during migration using internet resources. Employs background readings, authentic research data, and questions to experts to enable students to have meaningful learning experiences. (DDR)

  3. Obesity and African Americans

    MedlinePlus

    ... Data > Minority Population Profiles > Black/African American > Obesity Obesity and African Americans African American women have the ... ss6304.pdf [PDF | 3.38MB] HEALTH IMPACT OF OBESITY More than 80 percent of people with type ...

  4. The Effects of Temperature and Body Mass on Jump Performance of the Locust Locusta migratoria

    PubMed Central

    Snelling, Edward P.; Becker, Christie L.; Seymour, Roger S.

    2013-01-01

    Locusts jump by rapidly releasing energy from cuticular springs built into the hind femur that deform when the femur muscle contracts. This study is the first to examine the effect of temperature on jump energy at each life stage of any orthopteran. Ballistics and high-speed cinematography were used to quantify the energy, distance, and take-off angle of the jump at 15, 25, and 35°C in the locust Locusta migratoria. Allometric analysis across the five juvenile stages at 35°C reveals that jump distance (D; m) scales with body mass (M; g) according to the power equation D = 0.35M0.17±0.08 (95% CI), jump take-off angle (A; degrees) scales as A = 52.5M0.00±0.06, and jump energy (E; mJ per jump) scales as E = 1.91M1.14±0.09. Temperature has no significant effect on the exponent of these relationships, and only a modest effect on the elevation, with an overall Q10 of 1.08 for jump distance and 1.09 for jump energy. On average, adults jump 87% farther and with 74% more energy than predicted based on juvenile scaling data. The positive allometric scaling of jump distance and jump energy across the juvenile life stages is likely facilitated by the concomitant relative increase in the total length (Lf+t; mm) of the femur and tibia of the hind leg, Lf+t = 34.9M0.37±0.02. The weak temperature-dependence of jump performance can be traced to the maximum tension of the hind femur muscle and the energy storage capacity of the femur's cuticular springs. The disproportionately greater jump energy and jump distance of adults is associated with relatively longer (12%) legs and a relatively larger (11%) femur muscle cross-sectional area, which could allow more strain loading into the femur's cuticular springs. Augmented jump performance in volant adult locusts achieves the take-off velocity required to initiate flight. PMID:23967304

  5. The effects of temperature and body mass on jump performance of the locust Locusta migratoria.

    PubMed

    Snelling, Edward P; Becker, Christie L; Seymour, Roger S

    2013-01-01

    Locusts jump by rapidly releasing energy from cuticular springs built into the hind femur that deform when the femur muscle contracts. This study is the first to examine the effect of temperature on jump energy at each life stage of any orthopteran. Ballistics and high-speed cinematography were used to quantify the energy, distance, and take-off angle of the jump at 15, 25, and 35°C in the locust Locusta migratoria. Allometric analysis across the five juvenile stages at 35°C reveals that jump distance (D; m) scales with body mass (M; g) according to the power equation D = 0.35M (0.17±0.08 (95% CI)), jump take-off angle (A; degrees) scales as A = 52.5M (0.00±0.06), and jump energy (E; mJ per jump) scales as E = 1.91M (1.14±0.09). Temperature has no significant effect on the exponent of these relationships, and only a modest effect on the elevation, with an overall Q10 of 1.08 for jump distance and 1.09 for jump energy. On average, adults jump 87% farther and with 74% more energy than predicted based on juvenile scaling data. The positive allometric scaling of jump distance and jump energy across the juvenile life stages is likely facilitated by the concomitant relative increase in the total length (L f+t; mm) of the femur and tibia of the hind leg, L f+t = 34.9M (0.37±0.02). The weak temperature-dependence of jump performance can be traced to the maximum tension of the hind femur muscle and the energy storage capacity of the femur's cuticular springs. The disproportionately greater jump energy and jump distance of adults is associated with relatively longer (12%) legs and a relatively larger (11%) femur muscle cross-sectional area, which could allow more strain loading into the femur's cuticular springs. Augmented jump performance in volant adult locusts achieves the take-off velocity required to initiate flight. PMID:23967304

  6. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry

    PubMed Central

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J.

    2015-01-01

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin–Helmholtz instability in the shear layer behind the flapping wings. PMID:26040598

  7. Identification of a glycogenolysis-inhibiting peptide from the corpora cardiaca of locusts.

    PubMed

    Clynen, Elke; Huybrechts, Jurgen; Baggerman, Geert; Van Doorn, Jan; Van Der Horst, Dick; De Loof, Arnold; Schoofs, Liliane

    2003-08-01

    A mass spectrometric study of the peptidome of the neurohemal part of the corpora cardiaca of Locusta migratoria and Schistocerca gregaria shows that it contains several unknown peptides. We were able to identify the sequence of one of these peptides as pQSDLFLLSPK. This sequence is identical to the part of the Locusta insulin-related peptide (IRP) precursor that is situated between the signal peptide and the B-chain. We designated this peptide as IRP copeptide. This IRP copeptide is also present in the pars intercerebralis, which is likely to be the site of synthesis. It is identical in both L. migratoria and S. gregaria. It shows no effect on the hemolymph lipid concentration in vivo or muscle contraction in vitro. The IRP copeptide is able to cause a decreased phosphorylase activity in locust fat body in vitro, opposite to the effect of the adipokinetic hormones and therefore possibly represents a glycogenolysis-inhibiting peptide. PMID:12865323

  8. Activation of the prophenoloxidase cascade and initiation of nodule formation in locusts by bacterial lipopolysaccharides.

    PubMed

    Ratcliffe, N A; Brookman, J L; Rowley, A F

    1991-01-01

    The activation of the prophenoloxidase (proPO) system of the locusts, Schistocerca gregaria and Locusta migratoria, by several bacterial lipopolysaccharides (LPS) is described. Activation of proPO by LPS occurred only in the presence of whole blood homogenates and not with hemocyte lysate preparations alone. Levels of phenoloxidase generated by the different LPSs in vitro were also correlated with numbers of nodules formed in vivo by injection of these LPSs. This further strengthens the evidence for the involvement of proPO activation in the insect cellular defenses. Finally, the wisdom in using anticoagulants in order to stabilize fragile hemocytes in studies on the proPO system is discussed. PMID:1904828

  9. Impacts of fever on locust life-history traits: costs or benefits?

    PubMed Central

    Elliot, Sam L; Horton, Charlotte M; Blanford, Simon; Thomas, Matthew B

    2005-01-01

    Fever, like other mechanisms for defence against pathogens, may have positive and negative consequences for host fitness. In ectotherms, fever can be attained through modified behavioural thermoregulation. Here we examine potential costs of behavioural fever by holding adult, gregarious desert locusts at elevated temperatures simulating a range of fever intensities. We found no effect of fever temperatures on primary fitness correlates of survival and fecundity. However, flight capacity and mate competition were reduced, although there was no relation between time spent at fever temperatures and magnitude of the response. While these effects could indicate a direct cost of fever, they are also consistent with a shift towards the solitaria phase state that, in a field context, could be considered an adaptive life-history response to limit the impact of disease. These conflicting interpretations highlight the importance of considering complex defence mechanisms and trade-offs in an appropriate ecological context. PMID:17148161

  10. [Physiological features of the wing muscle fibers of Locusta migratoria locusts].

    PubMed

    Grigor'ev, V V

    1980-01-01

    In bifunctional dorsoventral muscle M-120 of the locust Locusta migratoria migratorioides three groups of fibers have been found which differ with respect to their electrophysiological properties. The evoked fast potentials in the fibers of caudal portion differed from fast potentials observed in the fibers of rostral and intermediate portions of the muscle. In the fibers of the caudal and intermediate portions of muscle, not only fast, but other depolarization potentials were also recorded which differ in the amplitude and duration, as well as the inhibitory postsynaptic potentials. It was shown that fibers in these three parts of the muscle differ in their voltage-current properties. It is concluded that different types of potentials are due to peculiarities of innervation and to structural heterogeneity of muscle fibers. PMID:6247866

  11. Developmental and activity-dependent plasticity of filiform hair receptors in the locust

    PubMed Central

    Pflüger, Hans-Joachim; Wolf, Harald

    2013-01-01

    A group of wind sensitive filiform hair receptors on the locust thorax and head makes contact onto a pair of identified interneuron, A4I1. The hair receptors' central nervous projections exhibit pronounced structural dynamics during nymphal development, for example, by gradually eliminating their ipsilateral dendritic field while maintaining the contralateral one. These changes are dependent not only on hormones controlling development but on neuronal activity as well. The hair-to-interneuron system has remarkably high gain (close to 1) and makes contact to flight steering muscles. During stationary flight in front of a wind tunnel, interneuron A4I1 is active in the wing beat rhythm, and in addition it responds strongly to stimulation of sensory hairs in its receptive field. A role of the hair-to-interneuron in flight steering is thus suggested. This system appears suitable for further study of developmental and activity-dependent plasticity in a sensorimotor context with known connectivity patterns. PMID:23986712

  12. The complex aerodynamic footprint of desert locusts revealed by large-volume tomographic particle image velocimetry.

    PubMed

    Henningsson, Per; Michaelis, Dirk; Nakata, Toshiyuki; Schanz, Daniel; Geisler, Reinhard; Schröder, Andreas; Bomphrey, Richard J

    2015-07-01

    Particle image velocimetry has been the preferred experimental technique with which to study the aerodynamics of animal flight for over a decade. In that time, hardware has become more accessible and the software has progressed from the acquisition of planes through the flow field to the reconstruction of small volumetric measurements. Until now, it has not been possible to capture large volumes that incorporate the full wavelength of the aerodynamic track left behind during a complete wingbeat cycle. Here, we use a unique apparatus to acquire the first instantaneous wake volume of a flying animal's entire wingbeat. We confirm the presence of wake deformation behind desert locusts and quantify the effect of that deformation on estimates of aerodynamic force and the efficiency of lift generation. We present previously undescribed vortex wake phenomena, including entrainment around the wing-tip vortices of a set of secondary vortices borne of Kelvin-Helmholtz instability in the shear layer behind the flapping wings. PMID:26040598

  13. Preparation and characterization of tragacanth-locust bean gum edible blend films.

    PubMed

    Mostafavi, Fatemeh Sadat; Kadkhodaee, Rassoul; Emadzadeh, Bahareh; Koocheki, Arash

    2016-03-30

    The present work introduces the structure and physicomechanical properties of a novel blend film made from binary solutions of gum tragacanth (GT) and locust bean gum (LBG) at different mixing ratios. Apparent viscosities and surface tensions of individual and blend gum solutions were also investigated. The viscosity data indicated that there was a distinct synergism between the two gums at all mixing ratios. FTIR spectra showed the existence of noncovalent intermolecular interactions between gums. The surface tensions of binary solutions were significantly lower than those of individual gums which is advantageous for coating applications. All films had homogenous and smooth surface morphology and their transparency, water vapour barrier and mechanical properties were improved by incorporating LBG in blend. The results of this study suggest that GT-LBG blend film, owing to its desirable properties, has the potential to be used as a new degradable food packaging material. PMID:26794942

  14. Effect of carboxymethylation on rheological and drug release characteristics of locust bean gum matrix tablets.

    PubMed

    Chakravorty, Amrita; Barman, Gouranga; Mukherjee, Sudipta; Sa, Biswanath

    2016-06-25

    This study was undertaken to investigate correlation between the carboxymethylation-induced rheological changes and drug release characteristics of locust bean gum (LBG) matrix tablets. LBG was derivatized to carboxymethyl LBG (CMLBG) and characterized by (13)C NMR, FTIR and elemental analyses. Rheological studies revealed that LBG, in contact with water, produced a strong elastic gel which swelled less due to lower penetration of water resulting in slower drug release. On the other hand, CMLBG formed a viscous polymer solution through which higher influx of water resulted in rapid swelling of the matrix and faster drug release. Although the release from a particular matrix was dependent on drugs' solubilities, CMLBG matrix tablet produced faster release of all the drugs than LBG matrix tablets. In conclusion, rheological study appeared to be an useful tool to predict release of drugs from polysaccharide matrix tablets. PMID:27083792

  15. [External proprioceptors of locust locomotor organs and their changes during early larval ontogenesis].

    PubMed

    Kuznetsova, T V; Severina, I Iu

    2009-01-01

    This work studies topography and structure of such important insect external proprioceptors as campaniform sensillae (CS). These mechanoreceptors are essential components of insect posture and locomotion regulation and participate in control of various forms of insect motor behavior (walking, jump, flight). There are traced their quantitative changes as well as differences in distribution of groups of these leg receptors at consecutive stages (from the 1st to the 4th) of ontogenetic development of larva of the locust Locusta migratoria L. The presence of groups of CS in proximal parts of extremities has been noted as early as in the 1st instar larvae. The CS groups in the wing pads were revealed only in the 4th instar larvae. The presented data allow connecting changes in structure and distribution of these proprioceptors on central generators of the locomotion rhythms. PMID:19764639

  16. Remarkable spatial memory in a migratory cardinalfish.

    PubMed

    Fukumori, Kayoko; Okuda, Noboru; Yamaoka, Kosaku; Yanagisawa, Yasunobu

    2010-03-01

    The ability to orient and navigate within a certain environment is essential for all animals, and spatial memory enables animals to remember the locations of such markers as predators, home, and food. Here we report that the migratory marine cardinalfish Apogon notatus has the potential to retain long-term spatial memory comparable to that of other animals. Female A. notatus establish a small territory on a shallow boulder bottom to pair and spawn with males. We carried out field research in two consecutive breeding seasons on territory settlement by individually marked females. Females maintained a territory at the same site throughout one breeding season. After overwintering in deep water, many of them (82.1%) returned to their breeding ground next spring and most occupied the same site as in the previous season, with only a 0.56 m shift on average. Our results suggest that female A. notatus have long-distance homing ability to pinpoint the exact location of their previous territory, and retain spatial memory for as long as 6 months. PMID:19784851

  17. Specialization and evolutionary branching within migratory populations

    PubMed Central

    Torney, Colin J.; Levin, Simon A.; Couzin, Iain D.

    2010-01-01

    Understanding the mechanisms that drive specialization and speciation within initially homogeneous populations is a fundamental challenge for evolutionary theory. It is an issue of relevance for significant open questions in biology concerning the generation and maintenance of biodiversity, the origins of reciprocal cooperation, and the efficient division of labor in social or colonial organisms. Several mathematical frameworks have been developed to address this question and models based on evolutionary game theory or the adaptive dynamics of phenotypic mutation have demonstrated the emergence of polymorphic, specialized populations. Here we focus on a ubiquitous biological phenomenon, migration. Individuals in our model may evolve the capacity to detect and follow an environmental cue that indicates a preferred migration route. The strategy space is defined by the level of investment in acquiring personal information about this route or the alternative tendency to follow the direction choice of others. The result is a relation between the migratory process and a game theoretic dynamic that is generally applicable to situations where information may be considered a public good. Through the use of an approximation of social interactions, we demonstrate the emergence of a stable, polymorphic population consisting of an uninformed subpopulation that is dependent upon a specialized group of leaders. The branching process is classified using the techniques of adaptive dynamics. PMID:21059935

  18. Orientation of migratory birds under ultraviolet light.

    PubMed

    Wiltschko, Roswitha; Munro, Ursula; Ford, Hugh; Stapput, Katrin; Thalau, Peter; Wiltschko, Wolfgang

    2014-05-01

    In view of the finding that cryptochrome 1a, the putative receptor molecule for the avian magnetic compass, is restricted to the ultraviolet single cones in European Robins, we studied the orientation behaviour of robins and Australian Silvereyes under monochromatic ultraviolet (UV) light. At low intensity UV light of 0.3 mW/m(2), birds showed normal migratory orientation by their inclination compass, with the directional information originating in radical pair processes in the eye. At 2.8 mW/m(2), robins showed an axial preference in the east-west axis, whereas silvereyes preferred an easterly direction. At 5.7 mW/m(2), robins changed direction to a north-south axis. When UV light was combined with yellow light, robins showed easterly 'fixed direction' responses, which changed to disorientation when their upper beak was locally anaesthetised with xylocaine, indicating that they were controlled by the magnetite-based receptors in the beak. Orientation under UV light thus appears to be similar to that observed under blue, turquoise and green light, albeit the UV responses occur at lower light levels, probably because of the greater light sensitivity of the UV cones. The orientation under UV light and green light suggests that at least at the level of the retina, magnetoreception and vision are largely independent of each other. PMID:24718656

  19. Fishing out collective memory of migratory schools.

    PubMed

    De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R; Marsili, Matteo

    2014-06-01

    Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals' preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution. PMID:24647905

  20. Fishing out collective memory of migratory schools

    PubMed Central

    De Luca, Giancarlo; Mariani, Patrizio; MacKenzie, Brian R.; Marsili, Matteo

    2014-01-01

    Animals form groups for many reasons, but there are costs and benefits associated with group formation. One of the benefits is collective memory. In groups on the move, social interactions play a crucial role in the cohesion and the ability to make consensus decisions. When migrating from spawning to feeding areas, fish schools need to retain a collective memory of the destination site over thousands of kilometres, and changes in group formation or individual preference can produce sudden changes in migration pathways. We propose a modelling framework, based on stochastic adaptive networks, that can reproduce this collective behaviour. We assume that three factors control group formation and school migration behaviour: the intensity of social interaction, the relative number of informed individuals and the strength of preference that informed individuals have for a particular migration area. We treat these factors independently and relate the individuals’ preferences to the experience and memory for certain migration sites. We demonstrate that removal of knowledgeable individuals or alteration of individual preference can produce rapid changes in group formation and collective behaviour. For example, intensive fishing targeting the migratory species and also their preferred prey can reduce both terms to a point at which migration to the destination sites is suddenly stopped. The conceptual approaches represented by our modelling framework may therefore be able to explain large-scale changes in fish migration and spatial distribution. PMID:24647905

  1. Optimal moult strategies in migratory birds.

    PubMed

    Barta, Zoltán; McNamara, John M; Houston, Alasdair I; Weber, Thomas P; Hedenström, Anders; Feró, Orsolya

    2008-01-27

    Avian migration, which involves billions of birds flying vast distances, is known to influence all aspects of avian life. Here we investigate how birds fit moult into an annual cycle determined by the need to migrate. Large variation exists in moulting patterns in relation to migration: for instance, moult can occur after breeding in the summer or after arrival in the wintering quarters. Here we use an optimal annual routine model to investigate why this variation exists. The modelled bird's decisions depend on the time of year, its energy reserves, breeding status, experience, flight feather quality and location. Our results suggest that the temporal and spatial variations in food are an important influence on a migratory bird's annual cycle. Summer moult occurs when food has a high peak on the breeding site in the summer, but it is less seasonal elsewhere. Winter moult occurs if there is a short period of high food availability in summer and a strong winter peak at different locations (i.e. the food is very seasonal but in opposite phase on these areas). This finding might explain why only long-distance migrants have a winter moult. PMID:17681914

  2. Pharmacological blockade of gap junctions induces repetitive surging of extracellular potassium within the locust CNS.

    PubMed

    Spong, Kristin E; Robertson, R Meldrum

    2013-10-01

    The maintenance of cellular ion homeostasis is crucial for optimal neural function and thus it is of great importance to understand its regulation. Glial cells are extensively coupled by gap junctions forming a network that is suggested to serve as a spatial buffer for potassium (K(+)) ions. We have investigated the role of glial spatial buffering in the regulation of extracellular K(+) concentration ([K(+)]o) within the locust metathoracic ganglion by pharmacologically inhibiting gap junctions. Using K(+)-sensitive microelectrodes, we measured [K(+)]o near the ventilatory neuropile while simultaneously recording the ventilatory rhythm as a model of neural circuit function. We found that blockade of gap junctions with either carbenoxolone (CBX), 18β-glycyrrhetinic acid (18β-GA) or meclofenamic acid (MFA) reliably induced repetitive [K(+)]o surges and caused a progressive impairment in the ability to maintain baseline [K(+)]o levels throughout the treatment period. We also show that a low dose of CBX that did not induce surging activity increased the vulnerability of locust neural tissue to spreading depression (SD) induced by Na(+)/K(+)-ATPase inhibition with ouabain. CBX pre-treatment increased the number of SD events induced by ouabain and hindered the recovery of [K(+)]o back to baseline levels between events. Our results suggest that glial spatial buffering through gap junctions plays an essential role in the regulation of [K(+)]o under normal conditions and also contributes to a component of [K(+)]o clearance following physiologically elevated levels of [K(+)]o. PMID:23916994

  3. Amplitude and dynamics of polarization-plane signaling in the central complex of the locust brain

    PubMed Central

    Bockhorst, Tobias

    2015-01-01

    The polarization pattern of skylight provides a compass cue that various insect species use for allocentric orientation. In the desert locust, Schistocerca gregaria, a network of neurons tuned to the electric field vector (E-vector) angle of polarized light is present in the central complex of the brain. Preferred E-vector angles vary along slices of neuropils in a compasslike fashion (polarotopy). We studied how the activity in this polarotopic population is modulated in ways suited to control compass-guided locomotion. To this end, we analyzed tuning profiles using measures of correlation between spike rate and E-vector angle and, furthermore, tested for adaptation to stationary angles. The results suggest that the polarotopy is stabilized by antagonistic integration across neurons with opponent tuning. Downstream to the input stage of the network, responses to stationary E-vector angles adapted quickly, which may correlate with a tendency to steer a steady course previously observed in tethered flying locusts. By contrast, rotating E-vectors corresponding to changes in heading direction under a natural sky elicited nonadapting responses. However, response amplitudes were particularly variable at the output stage, covarying with the level of ongoing activity. Moreover, the responses to rotating E-vector angles depended on the direction of rotation in an anticipatory manner. Our observations support a view of the central complex as a substrate of higher-stage processing that could assign contextual meaning to sensory input for motor control in goal-driven behaviors. Parallels to higher-stage processing of sensory information in vertebrates are discussed. PMID:25609107

  4. Effects of nitrate on nitrogen fixation and growth of black locust (Robinia pseudoacacia L. ) seedlings

    SciTech Connect

    Johnsen, K.H.

    1990-01-01

    N fertilization may affect the growth of black locust via effects on N fixation (NF) and N metabolism energy costs. This work examined the effects of nitrate (n) on NF and growth of black locust seedlings (BLS). Two experiments examined the effects of n on acetylene reduction, nodule biomass (NB), and n reductase activity of families using nodulated seedlings. Two additional experiments examined the effects of n using functional growth analysis. Nitrate was enriched with [sup 15]N and seedling N was partitioned into n and atmospheric N sources. Nitrate fertilization affected both NF and growth of BLS. High concentrations of n decreased both NB and activity. Nitrate additions generally increase total plant growth. Adjustments for seedling size via allometric principles are necessary to correctly interpret treatment effects on NF. Without such adjustments, n fertilization and family effects on general seedling growth confound analysis. Nitrate fertilization decreased NF primarily by decreasing dry matter partitioning to nodules. Low concentrations of n resulted in higher total seedling NB. Once, it was thought that low levels of soil N are needed to stimulate nodule growth and NF. Allometric analysis clearly indicated that low concentrations of n did not affect nodule growth directly but did so by increasing general seedling growth. Growth analyses were conducted to correct for confounding effects of differential plant size and internal N concentration resulting from different rates of n fertilization. These analyses showed that n fertilization increased BLS growth both by increasing seedling internal N concentrations and by increasing N productivity. The latter indicates that n utilization is more energy efficient than NF. High levels of n reductase activity were observed in leaves of BLS given n. Differences in energy costs might be partly attributable to photo-reduction of n and/or nitrite in the leaves.

  5. A novel locust (Schistocerca gregaria) serine protease inhibitor with a high affinity for neutrophil elastase

    PubMed Central

    Brillard-Bourdet, Michèle; Hamdaoui, Ahmed; Hajjar, Eric; Boudier, Christian; Reuter, Nathalie; Ehret-Sabatier, Laurence; Bieth, Joseph G.; Gauthier, Francis

    2006-01-01

    We have purified to homogeneity two forms of a new serine protease inhibitor specific for elastase/chymotrypsin from the ovary gland of the desert locust Schistocerca gregaria. This protein, greglin, has 83 amino acid residues and bears putative phosphorylation sites. Amino acid sequence alignments revealed no homology with pacifastin insect inhibitors and only a distant relationship with Kazal-type inhibitors. This was confirmed by computer-based structural studies. The most closely related homologue is a putative gene product from Ciona intestinalis with which it shares 38% sequence homology. Greglin is a fast-acting and tight binding inhibitor of human neutrophil elastase (kass=1.2×107 M−1·s−1, Ki=3.6 nM) and subtilisin. It also binds neutrophil cathepsin G, pancreatic elastase and chymotrypsin with a lower affinity (26 nM≤Ki≤153 nM), but does not inhibit neutrophil protease 3 or pancreatic trypsin. The capacity of greglin to inhibit neutrophil elastase was not significantly affected by exposure to acetonitrile, high temperature (90 °C), low or high pH (2.5–11.0), N-chlorosuccinimide-mediated oxidation or the proteolytic enzymes trypsin, papain and pseudolysin from Pseudomonas aeruginosa. Greglin efficiently inhibits the neutrophil elastase activity of sputum supernatants from cystic fibrosis patients. Its biological function in the locust ovary gland is currently unknown, but its physicochemical properties suggest that it can be used as a template to design a new generation of highly resistant elastase inhibitors for treating inflammatory diseases. PMID:16839309

  6. Amplitude and dynamics of polarization-plane signaling in the central complex of the locust brain.

    PubMed

    Bockhorst, Tobias; Homberg, Uwe

    2015-05-01

    The polarization pattern of skylight provides a compass cue that various insect species use for allocentric orientation. In the desert locust, Schistocerca gregaria, a network of neurons tuned to the electric field vector (E-vector) angle of polarized light is present in the central complex of the brain. Preferred E-vector angles vary along slices of neuropils in a compasslike fashion (polarotopy). We studied how the activity in this polarotopic population is modulated in ways suited to control compass-guided locomotion. To this end, we analyzed tuning profiles using measures of correlation between spike rate and E-vector angle and, furthermore, tested for adaptation to stationary angles. The results suggest that the polarotopy is stabilized by antagonistic integration across neurons with opponent tuning. Downstream to the input stage of the network, responses to stationary E-vector angles adapted quickly, which may correlate with a tendency to steer a steady course previously observed in tethered flying locusts. By contrast, rotating E-vectors corresponding to changes in heading direction under a natural sky elicited nonadapting responses. However, response amplitudes were particularly variable at the output stage, covarying with the level of ongoing activity. Moreover, the responses to rotating E-vector angles depended on the direction of rotation in an anticipatory manner. Our observations support a view of the central complex as a substrate of higher-stage processing that could assign contextual meaning to sensory input for motor control in goal-driven behaviors. Parallels to higher-stage processing of sensory information in vertebrates are discussed. PMID:25609107

  7. Greater migratory propensity in hosts lowers pathogen transmission and impacts

    PubMed Central

    Altizer, Sonia; Bartel, Rebecca A.

    2014-01-01

    Animal migrations are spectacular and migratory species have been shown to transmit pathogens that pose risks to human health. Although migration is commonly assumed to enhance pathogen dispersal, empirical work indicates that migration can often have the opposite effect of lowering disease risk.Key to assessing disease threats to migratory species is the ability to predict how migratory behaviour influences pathogen invasion success and impacts on migratory hosts, thus motivating a mechanistic understanding of migratory host-pathogen interactions.Here we develop a quantitative framework to examine pathogen transmission in animals that undergo two-way directed migrations between wintering and breeding grounds annually.Using the case of a pathogen transmitted during the hosts’ breeding season, we show that a more extreme migratory strategy (defined by the time spent away from the breeding site and the total distance migrated) lowers the probability of pathogen invasion. Moreover, if migration substantially lowers the survival probability of infected animals, then populations that spend comparatively less time at the breeding site or that migrate longer distances are less vulnerable to pathogen-induced population declines.These findings provide theoretical support for two non-exclusive mechanisms proposed to explain how seasonal migration can lower infection risk: (i) escape from habitats where parasite transmission stages have accumulated, and (ii) selective removal of infected hosts during strenuous journeys. Our work further suggests that barriers to long distance movement could increase pathogen prevalence for vulnerable species, an effect already seen in some animal species undergoing anthropogenically induced migratory shifts. PMID:24460702

  8. Moving across the border: modeling migratory bat populations

    USGS Publications Warehouse

    Ruscena, Wiederholt; López-Hoffman, Laura; Cline, Jon; Medellin, Rodrigo; Cryan, Paul M.; Russell, Amy; McCracken, Gary; Diffendorfer, Jay; Semmens, Darius J.

    2013-01-01

    The migration of animals across long distances and between multiple habitats presents a major challenge for conservation. For the migratory Mexican free-tailed bat (Tadarida brasiliensis mexicana), these challenges include identifying and protecting migratory routes and critical roosts in two countries, the United States and Mexico. Knowledge and conservation of bat migratory routes is critical in the face of increasing threats from climate change and wind turbines that might decrease migratory survival. We employ a new modeling approach for bat migration, network modeling, to simulate migratory routes between winter habitat in southern Mexico and summer breeding habitat in northern Mexico and the southwestern United States. We use the model to identify key migratory routes and the roosts of greatest conservation value to the overall population. We measure roost importance by the degree to which the overall bat population declined when the roost was removed from the model. The major migratory routes—those with the greatest number of migrants—were between winter habitat in southern Mexico and summer breeding roosts in Texas and the northern Mexican states of Sonora and Nuevo Leon. The summer breeding roosts in Texas, Sonora, and Nuevo Leon were the most important for maintaining population numbers and network structure – these are also the largest roosts. This modeling approach contributes to conservation efforts by identifying the most influential areas for bat populations, and can be used as a tool to improve our understanding of bat migration for other species. We anticipate this approach will help direct coordination of habitat protection across borders.

  9. Development of Matched (migratory Analytical Time Change Easy Detection) Method for Satellite-Tracked Migratory Birds

    NASA Astrophysics Data System (ADS)

    Doko, Tomoko; Chen, Wenbo; Higuchi, Hiroyoshi

    2016-06-01

    Satellite tracking technology has been used to reveal the migration patterns and flyways of migratory birds. In general, bird migration can be classified according to migration status. These statuses include the wintering period, spring migration, breeding period, and autumn migration. To determine the migration status, periods of these statuses should be individually determined, but there is no objective method to define 'a threshold date' for when an individual bird changes its status. The research objective is to develop an effective and objective method to determine threshold dates of migration status based on satellite-tracked data. The developed method was named the "MATCHED (Migratory Analytical Time Change Easy Detection) method". In order to demonstrate the method, data acquired from satellite-tracked Tundra Swans were used. MATCHED method is composed by six steps: 1) dataset preparation, 2) time frame creation, 3) automatic identification, 4) visualization of change points, 5) interpretation, and 6) manual correction. Accuracy was tested. In general, MATCHED method was proved powerful to identify the change points between migration status as well as stopovers. Nevertheless, identifying "exact" threshold dates is still challenging. Limitation and application of this method was discussed.

  10. Effects of xanthan, guar, carrageenan and locust bean gum addition on physical, chemical and sensory properties of meatballs.

    PubMed

    Demirci, Zeynep Ozben; Yılmaz, Ismail; Demirci, Ahmet Şukru

    2014-05-01

    This study evaluated the effects of xanthan gum, guar gum, carrageenan and locust bean gum on physical, chemical and sensory properties of meatballs. Meatball samples were produced with three different formulations including of 0.5, 1, and 1.5% each gum addition and gum added samples were compared with the control meatballs. Physical and chemical analyses were carried out on raw and cooked samples separately. Moisture contents of raw samples decreased by addition of gums. There were significant decreases (p < 0.05) in moisture and fat contents of raw and cooked meatball samples formulated with gum when compared with control. Ash contents and texture values increased with gum addition to meatballs. Meatball redness decreased with more gum addition in raw and cooked meatball samples, which means that addition of gums resulted in a lighter-coloured product. According to sensory analysis results, locust bean gum added (1%) samples were much preferred by the panelists. PMID:24803701

  11. Africans in America.

    ERIC Educational Resources Information Center

    Hart, Ayanna; Spangler, Earl

    This book introduces African-American history and culture to children. The first Africans in America came from many different regions and cultures, but became united in this country by being black, African, and slaves. Once in America, Africans began a long struggle for freedom which still continues. Slavery, the Civil War, emancipation, and the…

  12. African Outreach Workshop 1974.

    ERIC Educational Resources Information Center

    Schmidt, Nancy J.

    This report discusses the 1974 African Outreach Workshop planned and coordinated by the African Studies Program at the University of Illinois at Urbana-Champaign. Its major aim was to assist teachers in developing curriculum units on African using materials available in their local community. A second aim was for the African Studies Program to…

  13. Potential of the Desert Locust Schistocerca gregaria (Orthoptera: Acrididae) as an Unconventional Source of Dietary and Therapeutic Sterols

    PubMed Central

    Cheseto, Xavier; Kuate, Serge Philibert; Tchouassi, David P.; Ndung’u, Mary; Teal, Peter E. A.; Torto, Baldwyn

    2015-01-01

    Insects are increasingly being recognized not only as a source of food to feed the ever growing world population but also as potential sources of new products and therapeutic agents, among which are sterols. In this study, we sought to profile sterols and their derivatives present in the desert locust, Schistocerca gregaria, focusing on those with potential importance as dietary and therapeutic components for humans. Using coupled gas chromatography-mass spectrometry (GC-MS), we analyzed and compared the quantities of sterols in the different sections of the gut and tissues of the locust. In the gut, we identified 34 sterols which showed a patchy distribution, but with the highest composition in the foregut (55%) followed by midgut (31%) and hindgut (14%). Fed ad libitum on wheat seedlings, five sterols unique to the insect were detected. These sterols were identified as 7-dehydrocholesterol, desmosterol, fucosterol, (3β, 5α) cholesta-8, 14, 24-trien-3-ol, 4, 4-dimethyl, and (3β, 20R) cholesta-5, 24-dien-3, 20-diol with the first three having known health benefits in humans. Incubation of the fore-, mid- and hindgut with cholesterol-[4-13C] yielded eight derivatives, three of these were detected in the gut of the desert locust after it had consumed the vegetative diet but were not detected in the diet. Our study shows that the desert locust ingests phytosterols from a vegetative diet and, amplifies and metabolizes them into derivatives with potential salutary benefits and we discuss our findings in this context. PMID:25970517

  14. Predator versus Prey: Locust Looming-Detector Neuron and Behavioural Responses to Stimuli Representing Attacking Bird Predators

    PubMed Central

    Santer, Roger D.; Rind, F. Claire; Simmons, Peter J.

    2012-01-01

    Many arthropods possess escape-triggering neural mechanisms that help them evade predators. These mechanisms are important neuroethological models, but they are rarely investigated using predator-like stimuli because there is often insufficient information on real predator attacks. Locusts possess uniquely identifiable visual neurons (the descending contralateral movement detectors, DCMDs) that are well-studied looming motion detectors. The DCMDs trigger ‘glides’ in flying locusts, which are hypothesised to be appropriate last-ditch responses to the looms of avian predators. To date it has not been possible to study glides in response to stimuli simulating bird attacks because such attacks have not been characterised. We analyse video of wild black kites attacking flying locusts, and estimate kite attack speeds of 10.8±1.4 m/s. We estimate that the loom of a kite’s thorax towards a locust at these speeds should be characterised by a relatively low ratio of half size to speed (l/|v|) in the range 4–17 ms. Peak DCMD spike rate and gliding response occurrence are known to increase as l/|v| decreases for simple looming shapes. Using simulated looming discs, we investigate these trends and show that both DCMD and behavioural responses are strong to stimuli with kite-like l/|v| ratios. Adding wings to looming discs to produce a more realistic stimulus shape did not disrupt the overall relationships of DCMD and gliding occurrence to stimulus l/|v|. However, adding wings to looming discs did slightly reduce high frequency DCMD spike rates in the final stages of object approach, and slightly delay glide initiation. Looming discs with or without wings triggered glides closer to the time of collision as l/|v| declined, and relatively infrequently before collision at very low l/|v|. However, the performance of this system is in line with expectations for a last-ditch escape response. PMID:23209660

  15. Stopover ecology of a migratory ungulate.

    PubMed

    Sawyer, Hall; Kauffman, Matthew J

    2011-09-01

    1. Birds that migrate long distances use stopover sites to optimize fuel loads and complete migration as quickly as possible. Stopover use has been predicted to facilitate a time-minimization strategy in land migrants as well, but empirical tests have been lacking, and alternative migration strategies have not been considered. 2. We used fine-scale movement data to evaluate the ecological role of stopovers in migratory mule deer Odocoileus hemionus- a land migrant whose fitness is strongly influenced by energy intake rather than migration speed. 3. Although deer could easily complete migrations (range 18-144 km) in several days, they took an average of 3 weeks and spent 95% of that time in a series of stopover sites that had higher forage quality than movement corridors. Forage quality of stopovers increased with elevation and distance from winter range. Mule deer use of stopovers corresponded with a narrow phenological range, such that deer occupied stopovers 44 days prior to peak green-up, when forage quality was presumed to be highest. Mule deer used one stopover for every 5·3 and 6·7 km travelled during spring and autumn migrations, respectively, and used the same stopovers in consecutive years. 4. Study findings indicate that stopovers play a key role in the migration strategy of mule deer by allowing individuals to migrate in concert with plant phenology and maximize energy intake rather than speed. Our results suggest that stopover use may be more common among non-avian taxa than previously thought and, although the underlying migration strategies of temperate ungulates and birds are quite different, stopover use is important to both. 5. Exploring the role of stopovers in land migrants broadens the scope of stopover ecology and recognizes that the applied and theoretical benefits of stopover ecology need not be limited to avian taxa. PMID:21545586

  16. Modeling seasonal interactions in the population dynamics of migratory birds

    USGS Publications Warehouse

    Runge, M.C.; Marra, P.P.

    2005-01-01

    Understanding the population dynamics of migratory birds requires understanding the relevant biological events that occur during breeding, migratory, and overwintering periods. The few available population models for passerine birds focus on breeding-season events, disregard or oversimplify events during nonbreeding periods, and ignore interactions that occur between periods of the annual cycle. Identifying and explicitly incorporating seasonal interactions into population models for migratory birds could provide important insights about when population limitation actually occurs in the annual cycle. We present a population model for the annual cycle of a migratory bird, based on the American Redstart (Setophaga ruticilla) but more generally applicable, that examines the importance of seasonal interactions by incorporating: (1) density dependence during the breeding and winter seasons, (2) a carry-over effect of winter habitat on breeding-season productivity, and (3) the effects of behavioral dominance on seasonal and habitat specific demographic rates. First, we show that habitat availability on both the wintering and breeding grounds can strongly affect equilibrium population size and sex ratio. Second, sex ratio dynamics, as mediated by behavioral dominance, can affect all other aspects of population dynamics. Third, carry-over effects can be strong, especially when winter events are limiting. These results suggest that understanding the population dynamics of migratory birds may require more consideration of the seasonal interactions induced by carry-over effects and density dependence in multiple seasons. This model provides a framework in which to explore more fully these seasonal dynamics and a context for estimation of life history parameters.

  17. K⁺ absorption by locust gut and inhibition of ileal K⁺ and water transport by FGLamide allatostatins.

    PubMed

    Robertson, Lisa; Donini, Andrew; Lange, Angela B

    2014-09-15

    The scanning ion-selective electrode technique (SIET) was utilized for the first time in Locusta migratoria to characterize K(+) transport along the digestive tract and to determine the effect of two locust FGLamide allatostatins (FGLa/ASTs) on K(+) transport: a previously sequenced FGLa/AST from Schistocerca gregaria (Scg-AST-6; ARPYSFGL-NH2) and a newly sequenced FGLa/AST from L. migratoria (Locmi-FGLa/AST-2; LPVYNFGL-NH2). Regional differences in K(+) fluxes along the gut were evident, where K(+) efflux in vitro (or absorption into the hemolymph in vivo) was greatest at the anterior ileum, and lowest at the colon. Ileal K(+) efflux was inhibited by both Scg-AST-6 and Locmi-FGLa/AST-2, with maximal inhibition at 10(-10) and 10(-11) mol l(-1), respectively. Both FGLa/ASTs also inhibited cAMP-stimulated K(+) efflux from the ileum. Locmi-FGLa/AST-2 also inhibited efflux of water across the ileum. Locusts are terrestrial insects living in dry climates, risking desiccation and making water conservation a necessity. The results suggest that FGLa/ASTs may be acting as diuretics by increasing K(+) excretion and therefore increasing water excretion. Thus it is likely that FGLa/ASTs are involved in the control of hemolymph water and ion levels during feeding and digestion, to help the locust deal with the excess K(+) load (and subsequently fluid) when the meal is processed. PMID:25013112

  18. Photoreceptor projections and receptive fields in the dorsal rim area and main retina of the locust eye.

    PubMed

    Schmeling, Fabian; Tegtmeier, Jennifer; Kinoshita, Michiyo; Homberg, Uwe

    2015-05-01

    In many insect species, photoreceptors of a small dorsal rim area of the eye are specialized for sensitivity to the oscillation plane of polarized skylight and, thus, serve a role in sky compass orientation. To further understand peripheral mechanisms of polarized-light processing in the optic lobe, we have studied the projections of photoreceptors and their receptive fields in the main eye and dorsal rim area of the desert locust, a model system for polarization vision analysis. In both eye regions, one photoreceptor per ommatidium, R7, has a long visual fiber projecting through the lamina to the medulla. Axonal fibers from R7 receptors of the dorsal rim area have short side branches throughout the depth of the dorsal lamina and maintain retinotopic projections to the dorsal medulla following the first optic chiasma. Receptive fields of dorsal rim photoreceptors are considerably larger (average acceptance angle 33°) than those of the main eye (average acceptance angle 2.04°) and, taken together, cover almost the entire sky. The data challenge previous reports of two long visual fibers per ommatidium in the main eye of the locust and provide data for future analysis of peripheral networks underlying polarization opponency in the locust brain. PMID:25715758

  19. Photogrammetric reconstruction of high-resolution surface topographies and deformable wing kinematics of tethered locusts and free-flying hoverflies

    PubMed Central

    Walker, Simon M.; Thomas, Adrian L.R.; Taylor, Graham K.

    2008-01-01

    Here, we present a suite of photogrammetric methods for reconstructing insect wing kinematics, to provide instantaneous topographic maps of the wing surface. We filmed tethered locusts (Schistocerca gregaria) and free-flying hoverflies (Eristalis tenax) using four high-speed digital video cameras. We digitized multiple natural features and marked points on the wings using manual and automated tracking. Epipolar geometry was used to identify additional points on the hoverfly wing outline which were anatomically indistinguishable. The cameras were calibrated using a bundle adjustment technique that provides an estimate of the error associated with each individual data point. The mean absolute three-dimensional measurement error was 0.11 mm for the locust and 0.03 mm for the hoverfly. The error in the angle of incidence was at worst 0.51° (s.d.) for the locust and 0.88° (s.d.) for the hoverfly. The results we present are of unprecedented spatio-temporal resolution, and represent the most detailed measurements of insect wing kinematics to date. Variable spanwise twist and camber are prominent in the wingbeats of both the species, and are of such complexity that they would not be adequately captured by lower resolution techniques. The role of spanwise twist and camber in insect flight has yet to be fully understood, and accurate insect wing kinematics such as we present here are required to be sure of making valid predictions about their aerodynamic effects. PMID:18682361

  20. Comparative bio-safety and in vivo evaluation of native or modified locust bean gum-PVA IPN microspheres.

    PubMed

    Kaity, Santanu; Ghosh, Animesh

    2015-01-01

    Strategically developed natural polymer-based controlled release multiparticulate drug delivery systems have gained special interest for “spatial placement” and “temporal delivery” of drug molecules. In our earlier study, locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (LBG-PVA IPN), carboxymethylated locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (CMLBG-PVA IPN) and acrylamide grafted locust bean gum-poly(vinyl alcohol) interpenetrating polymer network (Am-g-LBG-PVA IPN) were prepared and characterized. The present study deals with accelerating stability testing, comparative bio-safety and single dose in vivo pharmacokinetic study of all three IPN microspheres for controlled oral delivery of buflomedil hydrochloride (BH). From the stability study, it was observed that the particles were stable throughout the study period. From toxicity and biodegradability study it was proved that the microspheres were safe for internal use and complied with bio-safety criterion. From the in vivo pharmacokinetic study in rabbits, it was observed that the CMLBG-PVA IPN microspheres possessed almost similar Tmax value with BH oral suspension. However, in comparison between the LBG-PVA and Am-g-LBG-PVA IPN microspheres, the later showed well controlled release property than the first in biological condition. Thus, this type of delivery system might be useful to achieve the lofty goals of the controlled release drug delivery. PMID:25307127

  1. Application of sugar maple and black locust to the biomass/energy plantation concept. Final report, April 1984

    SciTech Connect

    Mroz, G.D.; Jurgensen, M.F.; Lai, Y.Z.; Liechty, H.O.; Hamlin, D.C.; Gale, M.F.; Sajak, R.L.; Stinhilb, H.M.

    1986-08-01

    Forests in the Upper Lakes States region, composed predominantly of sugar maple and red maple with a large number of stems in small diameter classes, were evaluated for conversion to biomass/energy plantations. The study included examining the use of black locust as an interplant species to improve maple productivity. Available water and phosphorus were found to be highly correlated with site index and biomass on the sites. Skidding of trees with tops intact caused widespread disruption of forest floor horizons. Natural coppice regrowth on all sites was poor. Results indicate it is not feasible to coppice natural stands of northern hardwoods on a 4-year rotation. Survival of interplanted black locust was very poor due to susceptibility to frost. The potential of black locust as a biomass species for SRIC plantations was demonstrated by the exceptional growth of surviving individuals. A provenance trial of 20 seed sources showed variability in frost resistance among seed sources. Data is presented on the wood characteristics of seven northern hardwoods species show that young sprouts have higher moisture content, seasonal moisture content variation, higher extractive and ash content, a lower specific gravity and lower thermal stability. All species evaluated are comparable in terms of major chemical composition, caloric values, and extent of gasification. 111 refs., 11 figs., 35 tabs.

  2. Acephate affects migratory orientation of the white-throated sparrow (Zonotrichia albicollis)

    USGS Publications Warehouse

    Vyas, N.B.; Kuenzel, W.J.; Hill, E.F.; Sauer, J.R.

    1995-01-01

    Migratory white-throated sparrows (Zonotrichia albicollis) were exposed to acephate (acetylphosphoramidothioic acid O,S-dimethyl ester), an organophosphorus pesticide, to determine its effects on migratory orientation and behavior. Birds were also exposed to polarizer sheets to determine the mechanism by which acephate may affect migratory orientation. Adult birds exposed to 256 ppm acephate a.i. were not able to establish a preferred migratory orientation and exhibited random activity. All juvenile treatment groups displayed a seasonally correct southward migratory orientation. We hypothesize that acephate may have produced aberrant migratory behavior by affecting the memory of the migratory route and wintering ground. This experiment reveals that an environmentally relevant concentration of a common organophosphorus pesticide can alter migratory orientation, but its effect is markedly different between adult and juvenile sparrows. Results suggest that the survival of free-flying adult passerine migrants may be compromised following organophosphorus pesticide exposure.

  3. 76 FR 30186 - Proposed Information Collection; Migratory Birds and Wetlands Conservation Grant Programs

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ... Fish and Wildlife Service Proposed Information Collection; Migratory Birds and Wetlands Conservation...-2482 (telephone). SUPPLEMENTARY INFORMATION: I. Abstract The Division of Bird Habitat Conservation... 101-233 and the Neotropical Migratory Bird Conservation Act (NMBCA), Public Law 106-247....

  4. Migration costs drive convergence of threshold traits for migratory tactics.

    PubMed

    Sahashi, Genki; Morita, Kentaro

    2013-12-22

    Partial migration of some, but not all, members of a population is a common form of migration. We evaluated how migration costs influence which members migrate in 10 populations of two salmonid species. The migratory patterns of both species were evaluated based on the size at maturity for resident males, which is the threshold trait that determines the migratory tactics used within a population. In both species, this size was smaller in males located further from the sea, where migration costs are presumably higher. Moreover, the threshold sizes at maturity in males were correlated between both species. Our results suggest that migration costs are a significant convergent selective force on migratory tactics and life-history traits in nature. PMID:24197418

  5. Hybrid songbirds employ intermediate routes in a migratory divide.

    PubMed

    Delmore, Kira E; Irwin, Darren E

    2014-10-01

    Migratory divides are contact zones between populations that use different routes to navigate around unsuitable areas on seasonal migration. Hybrids in divides have been predicted to employ intermediate and potentially inferior routes. We provide the first direct test of this hypothesis, using light-level geolocators to track birds breeding in a hybrid zone between Swainson's thrushes in western Canada. Compared to parental forms, hybrids exhibited increased variability in their migratory routes, with some using intermediate routes that crossed arid and mountainous regions, and some using the same routes as one parental group on fall migration and the other on spring migration. Hybrids also tended to use geographically intermediate wintering sites. Analysis of genetic variation across the hybrid zone suggests moderately strong selection against hybrids. These results indicate that seasonal migratory behaviour might be a source of selection against hybrids, supporting a possible role for migration in speciation. PMID:25040456

  6. Migratory preparation associated alterations in pectoralis muscle biochemistry and proteome in Palearctic-Indian emberizid migratory finch, red-headed bunting, Emberiza bruniceps.

    PubMed

    Banerjee, Somanshu; Chaturvedi, Chandra Mohini

    2016-03-01

    Avian migration is an exceptionally high-energy-demanding process, which is met by the accumulation and utilization of fuel stores as well as the alterations in muscle physiology prior to their flight. Pre-migratory fattening coupled with changes in flight muscle metabolic enzymes and proteome is required to provide the necessary fuel and muscle performance required for migration. We studied how the serum metabolites (urea, uric acid, and creatinine), pectoralis muscle metabolites (glycogen, glucose, and cholesterol), muscle metabolic enzymes (CPT, HOAD, CS, MDH, CCO, CK, LDH, PFK, MLPL, and PK), liver lipogenic enzyme (FAS), and pectoralis muscle proteins get altered in pre-migratory and non-migratory buntings. Significantly increased pectoralis muscle fatty acid oxidation (CPT and HOAD activity), aerobic/anaerobic capacity (CS, CCO, and MDH activity), glycolytic capacity (PFK and PK activity), lipolysis (muscle LPL), and burst power (CK activity) were observed prior to the spring migration in pre-migratory buntings, whereas significantly increased pectoralis muscle anaerobic capacity (LDH activity) was observed in non-migratory buntings. Significant increase in the liver FAS showed profound lipogenesis prior to the spring migration. In this study, we have also investigated whether muscle has differential protein content during the pre-migratory and non-migratory phases of the annual migratory cycle. Twenty-nine proteins are identified and well characterized varying in expression significantly during the pre-migratory and non-migratory phases. These findings indicate that significant pre-migratory fattening and alterations in flight (pectoralis) muscle biochemistry and proteome in between the non- and pre-migratory phases may play a significant role in pre-migratory flight muscle preparation in these long-route migrants. PMID:26656601

  7. Identification of a new tachykinin from the midgut of the desert locust, Schistocerca gregaria, by ESI-Qq-oa-TOF mass spectrometry.

    PubMed

    Veelaert, D; Baggerman, G; Derua, R; Waelkens, E; Meeusen, T; Vande Water, G; De Loof, A; Schoofs, L

    1999-12-01

    This paper reports the purification of a tachykinin isoform from the midgut of the desert locust, Schistocerca gregaria. One hundred locust midguts were extracted in an acidified methanolic solvent, after which three HPLC column systems were used to obtain a pure peptide. A tachykinin immunoassay was used to monitor all collected fractions. After each purification step the purity of the sample was monitored by MALDI-TOF mass spectrometry. The pure peptide was sequenced by ESI-Qq-oa-TOF mass spectrometry. Edman degradation-based automated microsequencing and chemical synthesis confirmed the sequences. The midgut peptide, GNTKKAVPGFYGTRamide (Scg-midgut-TK), belongs to the tachykinin family with identified members in all vertebrate phyla and some invertebrate phyla: arthropods, annelids and molluscs. Scg-midgut-TK is the first tachykinin purified from midguts of the desert locust Schistocerca gregaria. In comparison to locust brain tachykinins, the midgut tachykinin is N-terminally extended. Similar to neuropeptide gamma, an N-terminally extended mammalian tachykinin, first isolated from rabbit intestine, the present identified locust intestinal tachykinin contains a putative dibasic cleavage site. PMID:10581195

  8. Plasticity of synaptic connections in sensory-motor pathways of the adult locust flight system.

    PubMed

    Wolf, H; Büschges, A

    1997-09-01

    We investigated possible roles of retrograde signals and competitive interactions in the lesion-induced reorganization of synaptic contacts in the locust CNS. Neuronal plasticity is elicited in the adult flight system by removal of afferents from the tegula, a mechanoreceptor organ at the base of the wing. We severed one hindwing organ and studied the resulting rearrangement of synaptic contacts between flight interneurons and afferent neurons from the remaining three tegulae (2 forewing, 1 hindwing). This was done by electric stimulation of afferents and intracellular recording from interneurons (and occasionally motoneurons). Two to three weeks after unilateral tegula lesion, connections between tegula afferents and flight interneurons were altered in the following way. 1) Axons from the forewing tegula on the operated side had established new synaptic contacts with metathoracic elevator interneurons. In addition, the amplitude of compound excitatory postsynaptic potentials elicited by electric stimulation was increased, indicating that a larger number of afferents connected to any given interneuron. 2) On the side contralateral to the lesion, connectivity between axons from the forewing tegula and elevator interneurons was decreased. 3) The efficacy of the (remaining) hindwing afferents appeared to be increased with regard to both synaptic transmission to interneurons and impact on flight motor pattern. 4) Flight motoneurons, which are normally restricted to the ipsilateral hemiganglion, sprouted across the ganglion midline after unilateral tegula removal and apparently established new synaptic contacts with tegula afferents on that side. The changes on the operated side are interpreted as occupation of synaptic space vacated on the interneurons by the severed hindwing afferents. On the contralateral side, the changes in synaptic contact must be elicited by retrograde signals from bilaterally arborizing flight interneurons, because tegula projections remain

  9. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and...

  10. 78 FR 33857 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  11. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and...

  12. 77 FR 5264 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-02

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  13. 75 FR 8989 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  14. 50 CFR 92.10 - Alaska Migratory Bird Co-management Council.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Alaska Migratory Bird Co-management... THE INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.10 Alaska Migratory Bird Co-management Council. (a) Establishment. The U.S. Fish and...

  15. 77 FR 65201 - Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest Household Survey

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-25

    ... Fish and Wildlife Service Proposed Information Collection; Alaska Migratory Bird Subsistence Harvest... 703-358- 2482 (telephone). SUPPLEMENTARY INFORMATION: I. Abstract The Migratory Bird Treaty Act of... Department of the Interior as the key agency responsible for managing migratory bird populations...

  16. 77 FR 39983 - Migratory Bird Hunting; Application for Approval of Fluoropolymeric Shot Coatings as Nontoxic for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

    ... Fish and Wildlife Service 50 CFR Part 20 RIN 1018-AY66 Migratory Bird Hunting; Application for Approval... INFORMATION CONTACT: George Allen, at 703-358-1825. SUPPLEMENTARY INFORMATION: Background The Migratory Bird Treaty Act of 1918 (Act) (16 U.S.C. 703-712 and 16 U.S.C. 742 a-j) implements migratory bird...

  17. 76 FR 5820 - Meeting Announcements: North American Wetlands Conservation Council; Neotropical Migratory Bird...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ...; Neotropical Migratory Bird Conservation Advisory Group AGENCY: Fish and Wildlife Service, Interior. ACTION... Migratory Bird Conservation Commission (Commission). This meeting is open to the public. The Advisory Group for the Neotropical Migratory Bird Conservation Act (NMBCA) grants program (Advisory Group) will...

  18. 75 FR 34758 - Proposed Information Collection; OMB Control Number 1018-0023; Migratory Bird Surveys

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... Fish and Wildlife Service Proposed Information Collection; OMB Control Number 1018-0023; Migratory Bird... ADDRESSES) or by telephone at (703) 358-2482. SUPPLEMENTARY INFORMATION: I. Abstract The Migratory Bird... Department of the Interior as the key agency responsible for (1) the wise management of migratory...

  19. Body condition and wind support initiate the shift of migratory direction and timing of nocturnal departure in a songbird.

    PubMed

    Schmaljohann, Heiko; Naef-Daenzer, Beat

    2011-11-01

    1. An innate migration strategy guides birds through space and time. Environmental variation further modulates individual behaviour within a genetically determined frame. In particular, ecological barriers could influence departure direction and its timing. A shift in the migratory direction in response to an ecological barrier could reveal how birds adjust their individual trajectories to environmental cues and body condition. 2. Northern wheatears of the Greenland/Iceland subspecies Oenanthe oenanthe leucorhoa arrive in Western Europe en route from their West African winter range. They then undergo an endogenously controlled shift in migratory direction from north to north-west to cross a large ecological barrier, the North Atlantic. We radiotracked these songbirds departing from Helgoland, a small island in the North Sea, over an unprecedented range of their journey. 3. Here, we show that both birds' body condition and the wind conditions that they encountered influenced the departure direction significantly. Jointly high fuel loads and favourable wind conditions enabled migrants to cross large stretches of sea. Birds in good condition departed early in the night heading to the sea towards their breeding areas, while birds with low fuel loads and/or flying in poor weather conditions departed in directions leading towards nearby mainland areas during the entire night. These areas could be reached even after setting off late at night. 4. Behavioural adjustment of migratory patterns is a critical adaptation for crossing ecological barriers. The observed variation in departure direction and time in relation to fuel load and wind revealed that these birds have an innate ability to respond by jointly incorporating internal information (body condition) and external information (wind support). PMID:21615404

  20. Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus) – implications for incipient speciation in island freshwater fish species

    PubMed Central

    2008-01-01

    Background Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory) taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species. Results Microchemical analyses of otolith isotopes (88Sr, 137Ba and 43Ca) differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae). Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP) fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices) provide a prezygotic reproductive isolation mechanism between the two ecotypes. Conclusion This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith microchemistry, morphology

  1. Synthesis of furans and pyrroles via migratory and double migratory cycloisomerization reactions of homopropargylic aldehydes and imines

    PubMed Central

    Shiroodi, Roohollah Kazem; Vera, Claudia I. Rivera; Dudnik, Alexander S.; Gevorgyan, Vladimir

    2015-01-01

    A novel gold-catalyzed divergent sysnthesis of furans and pyrroles employing readily available homopropargylic aldehydes and imines have been developed. The regiochemical outcome of this reaction is dependent on the substituent on the terminal alkyne of substrate. Thus, substrates possessing alkyl and aryl substituent at the alkyne moiety produce 2,3,5-substituted furans and pyrroles via a migratory cycloisomerizaton reaction. Whereas, their silicon analogues are capable to undergo a double migratory process leading to 2,3,4-substituted heterocycles. PMID:26185336

  2. Coding Characteristics of Spiking Local Interneurons During Imposed Limb Movements in the Locust

    PubMed Central

    Vidal-Gadea, A. G.; Jing, X. J.; Simpson, D.; Dewhirst, O. P.; Kondoh, Y.; Allen, R.

    2010-01-01

    The performance of adaptive behavior relies on continuous sensory feedback to produce relevant modifications to central motor patterns. The femoral chordotonal organ (FeCO) of the legs of the desert locust monitors the movements of the tibia about the femoro-tibial joint. A ventral midline population of spiking local interneurons in the metathoracic ganglia integrates inputs from the FeCO. We used a Wiener kernel cross-correlation method combined with a Gaussian white noise stimulation of the FeCO to completely characterize and model the output dynamics of the ventral midline population of interneurons. A wide range of responses were observed, and interneurons could be classified into three broad groups that received excitatory and inhibitory or principally inhibitory or excitatory synaptic inputs from the FeCO. Interneurons that received mixed inputs also had the greatest linear responses but primarily responded to extension of the tibia and were mostly sensitive to stimulus velocity. Interneurons that received principally inhibitory inputs were sensitive to extension and to joint position. A small group of interneurons received purely excitatory synaptic inputs and were also sensitive to tibial extension. In addition to capturing the linear and nonlinear dynamics of this population of interneurons, first- and second-order Wiener kernels revealed that the dynamics of the interneurons in the population were graded and formed a spectrum of responses whereby the activity of many cells appeared to be required to adequately describe a particular stimulus characteristic, typical of population coding. PMID:19955290

  3. Controlled release of Lactobacillus rhamnosus biofilm probiotics from alginate-locust bean gum microcapsules.

    PubMed

    Cheow, Wean Sin; Kiew, Tie Yi; Hadinoto, Kunn

    2014-03-15

    Chitosan-coated alginate microcapsules containing high-density biofilm Lactobacillus rhamnosus have been previously shown to exhibit higher freeze drying- and thermal-tolerance than their planktonic counterparts. However, their cell release profile remains poor due to the capsules' susceptibility to the gastric environment. Herein the effects of adding locust bean (LB) and xanthan (XT) gums to alginate (AGN) capsules on the stress tolerance and cell release profiles in simulated gastrointestinal fluids are investigated. Compared to the AGN-only capsules, the AGN-LB capsules exhibit improved stress tolerance (i.e. ≈ 6x for freeze drying, 100x for thermotolerance, 10x for acid), whereas the AGN-XT capsules only improve the acid tolerance. Importantly, the AGN-LB capsules possess the optimal cell release profile with a majority of cells released in the simulated intestinal juice than in the gastric juice. The AGN-LB capsules' superiority is attributed to their stronger interaction with the chitosan coating and high swelling capacity, thus delaying their bulk dissolution. PMID:24528770

  4. Fast Odor Learning Improves Reliability of Odor Responses in the Locust Antennal Lobe

    PubMed Central

    Bazhenov, Maxim; Stopfer, Mark; Sejnowski, Terrence J.; Laurent, Gilles

    2010-01-01

    Summary Recordings in the locust antennal lobe (AL) reveal activity-dependent, stimulus-specific changes in projection neuron (PN) and local neuron response patterns over repeated odor trials. During the first few trials, PN response intensity decreases, while spike time precision increases, and coherent oscillations, absent at first, quickly emerge. We examined this “fast odor learning” with a realistic computational model of the AL. Activity-dependent facilitation of AL inhibitory synapses was sufficient to simulate physiological recordings of fast learning. In addition, in experiments with noisy inputs, a network including synaptic facilitation of both inhibition and excitation responded with reliable spatiotemporal patterns from trial to trial despite the noise. A network lacking fast plasticity, however, responded with patterns that varied across trials, reflecting the input variability. Thus, our study suggests that fast olfactory learning results from stimulus-specific, activity-dependent synaptic facilitation and may improve the signal-to-noise ratio for repeatedly encountered odor stimuli. PMID:15882647

  5. The locust genome provides insight into swarm formation and long-distance flight

    PubMed Central

    Wang, Xianhui; Fang, Xiaodong; Yang, Pengcheng; Jiang, Xuanting; Jiang, Feng; Zhao, Dejian; Li, Bolei; Cui, Feng; Wei, Jianing; Ma, Chuan; Wang, Yundan; He, Jing; Luo, Yuan; Wang, Zhifeng; Guo, Xiaojiao; Guo, Wei; Wang, Xuesong; Zhang, Yi; Yang, Meiling; Hao, Shuguang; Chen, Bing; Ma, Zongyuan; Yu, Dan; Xiong, Zhiqiang; Zhu, Yabing; Fan, Dingding; Han, Lijuan; Wang, Bo; Chen, Yuanxin; Wang, Junwen; Yang, Lan; Zhao, Wei; Feng, Yue; Chen, Guanxing; Lian, Jinmin; Li, Qiye; Huang, Zhiyong; Yao, Xiaoming; Lv, Na; Zhang, Guojie; Li, Yingrui; Wang, Jian; Wang, Jun; Zhu, Baoli; Kang, Le

    2014-01-01

    Locusts are one of the world’s most destructive agricultural pests and represent a useful model system in entomology. Here we present a draft 6.5 Gb genome sequence of Locusta migratoria, which is the largest animal genome sequenced so far. Our findings indicate that the large genome size of L. migratoria is likely to be because of transposable element proliferation combined with slow rates of loss for these elements. Methylome and transcriptome analyses reveal complex regulatory mechanisms involved in microtubule dynamic-mediated synapse plasticity during phase change. We find significant expansion of gene families associated with energy consumption and detoxification, consistent with long-distance flight capacity and phytophagy. We report hundreds of potential insecticide target genes, including cys-loop ligand-gated ion channels, G-protein-coupled receptors and lethal genes. The L. migratoria genome sequence offers new insights into the biology and sustainable management of this pest species, and will promote its wide use as a model system. PMID:24423660

  6. Separate effects of macronutrient concentration and balance on plastic gut responses in locusts.

    PubMed

    Raubenheimer, David; Bassil, Kate

    2007-11-01

    It is well established that animal guts are phenotypically plastic, adjusting inter-alia to diet quality. However, the relative contributions due to the two principal dimensions of diet "quality"--nutrient concentration and nutrient balance--remain to be teased apart. We report an experiment using synthetic foods in which the balance and overall concentration (in relation to indigestible cellulose) of protein and digestible carbohydrate were varied orthogonally, and the effects on the dry mass of locust guts measured. There were three principal results: (1) larger guts were associated with dilute compared with concentrated diets, suggesting a compensatory response to ameliorate the impact of reduced diet quality; (2) there was, by contrast, an anti-compensatory response to nutrient imbalance, where larger guts were associated with surplus protein intake; (3) the experimental group given the food that contained low protein and low cellulose, the composition that predicted the smallest guts, showed a bimodal response in which half of the insects had guts that were larger than expected for their cellulose intake, suggesting that they were able to respond to a protein-related cue in the absence of significant dietary fibre. We discuss these results in relation to regulatory theory. PMID:17628805

  7. Protein mediated cholesterol absorption in locusts Schistocerca gregaria (Forskal) and Locusta migratoria (Linn).

    PubMed

    Upadhyay, Ravi Kant; Agarwal, H C; Dhar, Ravi

    2002-02-01

    Absorption and transport of 3H cholesterol from the midgut to hemolymph and other tissues was studied in the locusts Schistocerca gregaria and Locusta migratoria. S. gregaria are able to absorb dietary cholesterol in the midgut and release into the hemolymph in vivo and into the incubation medium in virto. Certain proteins of midgut origin are involved in the absorption and release of cholesterol. The proteins designated as cholesterol binding proteins (CBP's) were fractionated by gel filtration chromatography using Sepharose CL-6B-200 column. Presence of a protein and its binding with cholesterol is confirmed by TCA precipitation after subsequent incubation of midgut in the incubation medium. Cholesterol binding with the proteins was also confirmed in native polyacrylamide gel electrophoresis. Biosynthesis of this protein takes place in the midgut which is inhibited by a protein synthesis inhibitor, cycloheximide. It also inhibits absorption and release of cholesterol from the midgut. The cholesterol binding activity was associated with a peak containing proteins ranging from molecular weights of 17-32 kDa in SDS-PAGE gels. Treatment of midgut with cycloheximide resulted in reduced cholesterol binding activity. Dilipidation of mucin and transport in presence of bile salts yielded a higher cholesterol binding activity. Although the absorption and release of cholesterol was observed in the hemolymph of both sexes, the ovary exhibited higher cholesterol binding as compared to testis. PMID:12622177

  8. Biosynthesis of locust lipophorin. Apolipophorins I and II originate from a common precursor.

    PubMed

    Weers, P M; Van Marrewijk, W J; Beenakkers, A M; Van der Horst, D J

    1993-02-25

    Biosynthesis of apolipophorins of high density lipophorin of the locust Locusta migratoria was studied in vitro. Analysis of immunoprecipitates from homogenates of in vitro labeled fat body revealed a common precursor for apolipophorin I (apoLp-I, M(r) 220,000) and apolipophorin II (apoLp-II, M(r) 72,000) with a molecular mass of approximately 280 kDa. Pulsechase experiments showed that this high molecular mass precursor is cleaved into apoLp-I and apoLp-II which subsequently are secreted as high density lipophorin from the fat body. The time required for the complete synthesis and secretion was estimated to be approximately 35 min. Both apolipophorins are glycoproteins as demonstrated by the incorporation of [3H]mannose. Treatment of [3H]mannose-labeled apolipophorin with endoglycosidase H resulted in the complete removal of the incorporated [3H]mannose. Endoglycosidase H treatment of [3H]leucine-labeled apolipophorins caused a reduction in molecular mass of approximately 3 kDa for apoLp-I and 3.5 kDa for apoLp-II, suggesting the N-linked carbohydrate content to be 1-2 and 5%, respectively. Incubation of fat body tissue in the presence of low concentrations of tunicamycin led to the synthesis and release of nonglycosylated apolipophorins. PMID:8440714

  9. Nanoreticulations of etherified locust bean polysaccharide for controlled oral delivery of lamivudine.

    PubMed

    Maiti, Sabyasachi; Mondol, Ranjit; Sa, Biswanath

    2014-04-01

    Herein, an aqueous solution of etherified locust bean polysaccharide (ELBP) containing lamivudine was reticulated in presence of trivalent aluminium (Al(3+)) ions to nanoscale level (43.82-197.70 nm) by surfactant assisted homogenization-reticulation technique. The variation in aluminium chloride (AlCl3) strength (1.5-3.5% (w/v)) and drug:ELBP weight ratio (0.11-0.43) affected the properties of the nanoreticulations. Regardless of the variables, a maximum of ∼44% drug entrapment efficiency was noted. In simulated intestinal fluid (phosphate buffer solution, pH 7.4), the drug release rate was inversely proportional to the strength of AlCl3; but followed a proportional relationship with the drug:ELBP ratio. The mechanism of drug release shifted from Fickian diffusion to anomalous transport as the salt strength was increased above 2.5% (w/v). At intermediate drug:ELBP ratio, the drug release rate was regulated by polymer chain relaxation as opposed to simple diffusion mechanism. Fourier transform infrared spectroscopy did not show any evidence of chemical interaction between the drug and ELBP. Thermal analysis and X-ray diffraction studies suggested amorphous dispersion of drug in the nanoreticulations. Thus, the nanoreticulations were expected to absorb via intestine and phagocytosed by the virus-infected hepatic macrophages and hence could be useful for controlled delivery of lamivudine avoiding dose-dependent toxicity of the drug. PMID:24463266

  10. Phytohormone and assimilate profiles in emasculated flowers of the black locust (Robinia pseudoacacia) during development.

    PubMed

    Sun, Peng; Yuan, Cunquan; Dai, Li; Xi, Yang; Li, Yunfei; Hu, Ruiyang; Sun, Yuhan; Xu, Zhaohe; Li, Yun

    2013-09-01

    Emasculation and bagging of flowers, which are widely used in the controlled pollination of monoclinous plants, may induce premature senescence, flower abscission and low fruit set. To determine the mechanism responsible for these phenomena, levels of abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid (IAA), ethylene, soluble sugars, reducing sugars and free amino acids in black locust (Robinia pseudoacacia) flowers subjected to different treatments were quantified at different developmental stages. The phytohormones and assimilates were also quantified in untreated flowers to investigate the presence of discernible patterns. The levels of ethylene and ABA in emasculated and bagged (EB) flowers increased prematurely compared with those of untreated flowers, whereas the content of reducing sugars in EB flowers decreased compared with that of untreated flowers. These results indicated that the premature increase in ethylene and ABA synthesis, and the decrease in reducing sugars content, in EB flowers may cause flower abscission and result in low fruit set, which may be relevant for assimilate applications and future research on the regulation of controlled pollinations with exogenous phytohormones. PMID:24013897

  11. The dynamics of yolk deposition in the desert locust Schistocerca gregaria.

    PubMed

    Peel, Andrew D; Akam, Michael

    2007-05-01

    Injection of the protein dye Fast Green or the fluid-phase probe fluorescein dextran into the haemolymph of vitellogenic female desert locusts (Schistocerca gregaria) resulted in their incorporation into oocytes. We used Fast Green to study the physical dynamics of yolk deposition during vitellogenesis. Timed maternal injections of Fast Green reveal that yolk deposition and oocyte growth are inextricably linked during vitellogenesis, and that little or no yolk movement occurs within oocytes prior to embryogenesis. The yolk granules laid down early during vitellogenesis lie at the centre of the egg, with yolk granules deposited later packed around these, such that they lie progressively closer to the eventual egg surface. In contrast, during early embryogenesis yolk granules migrate in a manner that closely resembles the movement of early cleavage nuclei. We find fluorescein dextran to be a clear, robust and developmentally inert marker for the timing of maternal injections relative to vitellogenesis in S. gregaria, and we propose its use in parental RNAi or morpholino knockdown experiments. With such experiments in mind, we show that fluorescein-labelled DNA oligonucleotides are internalized within oocytes during vitellogenesis. However, neither Fast Green, fluorescein dextran nor fluorescein-labelled DNA oligonucleotides are detectably transferred from yolk granules to embryonic cells during embryogenesis, and our initial attempts at parental RNAi using maternal injections of dsRNA targeted to late vitellogenesis have proved unsuccessful. PMID:17382957

  12. Differential activation of serotonergic neurons during short- and long-term gregarization of desert locusts

    PubMed Central

    Rogers, Stephen M.; Ott, Swidbert R.

    2015-01-01

    Serotonin is a neurochemical with evolutionarily conserved roles in orchestrating nervous system function and behavioural plasticity. A dramatic example is the rapid transformation of desert locusts from cryptic asocial animals into gregarious crop pests that occurs when drought forces them to accumulate on dwindling resources, triggering a profound alteration of behaviour within just a few hours. The onset of crowding induces a surge in serotonin within their thoracic ganglia that is sufficient and necessary to induce the switch from solitarious to gregarious behaviour. To identify the neurons responsible, we have analysed how acute exposure to three gregarizing stimuli—crowding, touching the hind legs or seeing and smelling other locusts—and prolonged group living affect the expression of serotonin in individual neurons in the thoracic ganglia. Quantitative analysis of cell body immunofluorescence revealed three classes of neurons with distinct expressional responses. All ganglia contained neurons that responded to multiple gregarizing stimuli with increased expression. A second class showed increased expression only in response to intense visual and olfactory stimuli from conspecifics. Prolonged group living affected a third and entirely different set of neurons, revealing a two-tiered role of the serotonergic system as both initiator and substrate of socially induced plasticity. This demonstrates the critical importance of ontogenetic time for understanding the function of serotonin in the reorganization of behaviour. PMID:25520357

  13. Spatiotemporal stimulus properties modulate responses to trajectory changes in a locust looming-sensitive pathway.

    PubMed

    Dick, Paul C; Gray, John R

    2014-05-01

    The lobula giant movement detector (LGMD) and descending contralateral movement detector (DCMD) constitute one motion-sensitive pathway in the locust visual system that is implicated in collision-avoidance behaviors. While this pathway is thought to respond preferentially to objects approaching on a direct collision course, emerging studies suggest the firing rate is able to monitor more complicated movements that would occur under natural conditions. While previous studies have compared the response of the DCMD to objects on collision courses that travel at different speeds, velocity has not been manipulated for other simple or compound trajectories. Here we test the possibility that the LGMD/DCMD pathway is capable of responding uniquely to complex aspects of object motion, including translation and trajectory changes at different velocities. We found that the response of the DCMD to translational motion initiated in the caudal visual field was a low-amplitude peak in firing rate that occurred before the object crossed 90° azimuth that was invariant to different object velocities. Direct looms at different velocities resulted in peak firing rates that occurred later in time and with greater amplitude for higher velocities. In response to transitions from translational motion to a collision course, the firing rate change depended on both the location within the visual field and the velocity. These results suggest that this pathway is capable of conveying information about multiple properties of a moving object's trajectory. PMID:24478154

  14. Octopamine mediated relaxation of maintained and catch tension in locust skeletal muscle.

    PubMed Central

    Evans, P D; Siegler, M V

    1982-01-01

    1. The modulatory actions of an identified octopaminergic neurone (DUMETi) that projects to the extensor-tibiae muscle of the locust hind leg depend upon the frequency of stimulation of the slow motoneurone (SETi) to this muscle. 2. At low frequencies of SETi stimulation (1Hz and below) the predominant modulatory effects are increases in the amplitude and relaxation rate of twitch tension. At higher frequencies, where twitches summate but tetanus is incomplete (up to 20 Hz), the reduction of maintained tension becomes considerably more important. 3. Both octopamine application and DUMETi stimulation reduce the amount of catch tension displayed by the extensor muscle when SETi is fired in a variety of different stimulus patterns. The extensor-tibiae muscle is itself 'pattern sensitive' since is shows a 'positive spacing effect' when SETi is stimulated at an average frequency of 1 Hz. 4. It is suggested that a primary function of DUMETi is to change the response of the muscle from one that favours maintenance of posture to one that favours rapid changes in joint position or force, such as might occur during locomotion. PMID:6808122

  15. Dendritic projections of different types of octopaminergic unpaired median neurons in the locust metathoracic ganglion.

    PubMed

    Kononenko, Natalia L; Pflüger, Hans-Joachim

    2007-10-01

    Octopaminergic dorsal unpaired median (DUM) neurons of locust thoracic ganglia are important components of motor networks and are divided into various sub-populations. We have examined individually stained metathoracic DUM neurons, their dendritic projection patterns, and their relationship to specific architectural features of the metathoracic ganglion, such as longitudinal tracts, transverse commissures, and well-defined sensory neuropils. The detailed branching patterns of individually characterized DUM neurons of various types were analyzed in vibratome sections in which architectural features were revealed by using antibodies against tubulin and synapsin. Whereas DUM3,4,5 and DUM5 neurons (the group innervating leg and "non-wing-power" muscles) had many ventral and dorsal branches, DUM1 and DUM3,4 neurons (innervating "wing-power" muscles) branched extensively only in dorsal areas. The structure of DUM3 neurons differed markedly from that of the other DUM neurons examined in that they sent branches into dorsal areas and had differently structured side branches that mostly extended laterally. The differences between the branching patterns of these neurons were quantified by using currently available new reconstruction algorithms. These structural differences between the various classes of DUM neurons corresponded to differences in their function and biophysical properties. PMID:17505844

  16. Impact of gelation period on modified locust bean-alginate interpenetrating beads for oral glipizide delivery.

    PubMed

    Dey, Paramita; Sa, Biswanath; Maiti, Sabyasachi

    2015-05-01

    In this work, the effect of hydrogelation period in the design of glipizide-loaded biopolymer-based interpenetrating network (IPN) beads was investigated. Carboxymethyl locust bean gum and sodium alginate IPN beads were prepared by ionic crosslinking method using aqueous aluminium chloride salt solution as gelation medium. The longer exposure of the IPN beads in the gelation medium caused a considerable loss of the drug (∼ 8%), and also affected their surface morphology and drug release performance. Spherical shape of the IPN beads was observed under scanning electron microscope (SEM). The diameter of IPN beads increased with increasing gelation time. The IPNs cured for 0.5h exhibited slower drug release kinetics in HCl (pH 1.2) and phosphate buffer (pH 7.4) solution than those incubated for 1-2h. The drug release occurred at a faster rate in phosphate buffer solution and continued for a minimum period of 8h. The IPNs cured for the lowest period obeyed polymer chain-relaxation phenomenon as dominating mechanism for drug release. However, all the IPNs followed anomalous mechanism of drug transport. The drug release corroborated well with pH-dependent swelling behaviors of the IPNs. Thus, IPN beads cured for 0.5h were found most suitable for controlled delivery of BCS class II anti-diabetic drug glipizide. PMID:25745842

  17. Locust bean gum in the development of sustained release mucoadhesive macromolecules of aceclofenac.

    PubMed

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Maheriya, Pankaj M; Nagar, Bhanu J

    2014-11-26

    The study shows the development and optimization of locust bean gum (LBG)-alginate mucoadhesive macromolecules containing aceclofenac through ionotropic-gelation using 3(2) factorial design. The effect of amount of LBG and sodium alginate on drug entrapment efficiency (%DEE), % mucoadhesion at 8h (M8) and % in vitro drug release at 10h (%Q10h) were optimized. The percentage yield, average size and DEE of macromolecules were found within the range of 93.19 to 96.65%, 1.328 ± 0.11 to 1.428 ± 0.13 μm, and 56.37 to 68.54%, respectively. The macromolecules were also characterized by SEM, FTIR and DSC. The in vitro drug release from these macromolecules (84.95 ± 2.02 to 95.33 ± 1.56% at 10h) exhibited sustained release (first-order) pattern with super case-II transport mechanism. The swelling and mucoadhesivity of these macromolecules were affected by pH of the medium. The design established the role of derived polynomial equations and plots in predicting the values of dependent variables for the preparation and optimization. PMID:25256468

  18. Optimization of reaction conditions by RSM and structure characterization of sulfated locust bean gum.

    PubMed

    Wang, Junlong; Yang, Ting; Tian, Jia; Liu, Wenxi; Jing, Fan; Yao, Jian; Zhang, Ji; Lei, Ziqiang

    2014-12-19

    Sulfated derivatives of galactomannan from locust bean gum (LBG) with the degree of substitution (DS) of 0.34-1.07 were synthesized using chlorosulfonic acid/pyridine (CSA/Py) method. Box-Behnken design (BBD) of response surface methodology (RSM) was employed to optimize the reaction conditions. Results of FT-IR and X-ray photoelectron spectroscopy (XPS) indicated that SO3H groups were widely present in sulfated LBG (SLBG). (13)C NMR result revealed that sulfation had occurred and C-6 substitution was predominant in SLBG. All sulfated samples showed a decrease in Mw and more broad molar mass distribution in size exclusion chromatography combined with laser light scattering (SEC-LLS) analysis. Results of MW - [Formula: see text] showed a decrease in fractal dimension (df) value. Laser light scattering results also showed a conformation transition from a compact chain conformation of branched clusters to a random coil conformation of SLBG. Compared to LBG and SLBG with low DS and molecular weight, SLBG2 exhibited an internal structure of random coil with a DS of 1.07. DS and molecular weight had great influence on its conformation in aqueous solution. Our results confirmed that the degradation of polysaccharide and SO3H groups improved significantly the stiffness of the chains due to the electrostatic effect. PMID:25263904

  19. Alginate beads of Captopril using galactomannan containing Senna tora gum, guar gum and locust bean gum.

    PubMed

    Pawar, Harshal A; Lalitha, K G; Ruckmani, K

    2015-05-01

    Gastro-retentive Captopril loaded alginate beads were prepared by an ionotropic gelation method using sodium alginate in combination with natural gums containing galactomannans (Senna tora seed gum, guar gum and locust bean gum) in the presence of calcium chloride. The process variables such as concentration of sodium alginate/natural polymer, concentration of calcium chloride, curing time, stirring speed and drying condition were optimized. Prepared beads were evaluated for various parameters such as flow property, drug content and entrapment efficiency, size and shape, and swelling index. Surface morphology of the beads was studied using scanning electron microscopy. In vitro mucoadhesion and in vitro drug release studies were carried out on the prepared beads. From the entrapment efficiency and dissolution study, it was concluded that galactomannans in combination with sodium alginate show sustained release property. The bead formulation F4 prepared using combination of sodium alginate and guar gums in the ratio 2:1 showed satisfactory sustained release for 12h. The release of Captopril from the prepared beads was found to be controlled by the swelling of the polymer followed by drug diffusion through the swelled polymer and slow erosion of the beads. PMID:25720832

  20. Respiratory dynamics of discontinuous gas exchange in the tracheal system of the desert locust, Schistocerca gregaria.

    PubMed

    Groenewald, Berlizé; Hetz, Stefan K; Chown, Steven L; Terblanche, John S

    2012-07-01

    Gas exchange dynamics in insects is of fundamental importance to understanding evolved variation in breathing patterns, such as discontinuous gas exchange cycles (DGCs). Most insects do not rely solely on diffusion for the exchange of respiratory gases but may also make use of respiratory movements (active ventilation) to supplement gas exchange at rest. However, their temporal dynamics have not been widely investigated. Here, intratracheal pressure, V(CO2) and body movements of the desert locust Schistocerca gregaria were measured simultaneously during the DGC and revealed several important aspects of gas exchange dynamics. First, S. gregaria employs two different ventilatory strategies, one involving dorso-ventral contractions and the other longitudinal telescoping movements. Second, although a true spiracular closed (C)-phase of the DGC could be identified by means of subatmospheric intratracheal pressure recordings, some CO(2) continued to be released. Third, strong pumping actions do not necessarily lead to CO(2) release and could be used to ensure mixing of gases in the closed tracheal system, or enhance water vapour reabsorption into the haemolymph from fluid-filled tracheole tips by increasing the hydrostatic pressure or forcing fluid into the haemocoel. Finally, this work showed that the C-phase of the DGC can occur at any pressure. These results provide further insights into the mechanistic basis of insect gas exchange. PMID:22675191

  1. A temperature rise reduces trial-to-trial variability of locust auditory neuron responses.

    PubMed

    Eberhard, Monika J B; Schleimer, Jan-Hendrik; Schreiber, Susanne; Ronacher, Bernhard

    2015-09-01

    The neurophysiology of ectothermic animals, such as insects, is affected by environmental temperature, as their body temperature fluctuates with ambient conditions. Changes in temperature alter properties of neurons and, consequently, have an impact on the processing of information. Nevertheless, nervous system function is often maintained over a broad temperature range, exhibiting a surprising robustness to variations in temperature. A special problem arises for acoustically communicating insects, as in these animals mate recognition and mate localization typically rely on the decoding of fast amplitude modulations in calling and courtship songs. In the auditory periphery, however, temporal resolution is constrained by intrinsic neuronal noise. Such noise predominantly arises from the stochasticity of ion channel gating and potentially impairs the processing of sensory signals. On the basis of intracellular recordings of locust auditory neurons, we show that intrinsic neuronal variability on the level of spikes is reduced with increasing temperature. We use a detailed mathematical model including stochastic ion channel gating to shed light on the underlying biophysical mechanisms in auditory receptor neurons: because of a redistribution of channel-induced current noise toward higher frequencies and specifics of the temperature dependence of the membrane impedance, membrane potential noise is indeed reduced at higher temperatures. This finding holds under generic conditions and physiologically plausible assumptions on the temperature dependence of the channels' kinetics and peak conductances. We demonstrate that the identified mechanism also can explain the experimentally observed reduction of spike timing variability at higher temperatures. PMID:26041833

  2. MIGRATORY BIRDS OF CENTRAL WASHINGTON AS RESERVOIRS OF 'CAMPYLOBACTER JEJUNI'

    EPA Science Inventory

    Migratory ducks, Canada geese, and sandhill crane from the Pacific North American Flyway have been screened for Campylobacter spp. Two hundred ninety-eight samples from these birds were examined and the carrier rates detected were as follows: sandhill crane, 81 percent; ducks, 73...

  3. 76 FR 39368 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... abatement permit holder may use captive-bred raptors held under his or her migratory bird master falconry permit for abatement activities without transferring them to his or her abatement permit, provided the... used under his or her abatement permit. Raptors used under a Federal abatement permit must be...

  4. Florida Migratory Child Compensatory Program Announcement of Staff Development Activities.

    ERIC Educational Resources Information Center

    Florida Atlantic Univ., Boca Raton.

    The intent given for the Florida Migratory Child Compensatory Program staff development activities is to assist local individual teachers, teacher groups, schools, and school districts in the implementation of in-service training activities that will enhance improvement of the individual teacher. Twenty-five experiences provided by…

  5. 75 FR 9314 - Migratory Bird Permits; Control of Purple Swamphens

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... (71 FR 50194, August 24, 2006) to revise the list of migratory birds found at 50 CFR 10.13. We... Proposed Rule We received two comments on the proposed rule published on August 22, 2008 (70 FR 49631-49634... Native American Tribal Governments'' (59 FR 22951), Executive Order 13175, and 512 DM 2, we...

  6. 76 FR 67650 - Migratory Bird Permits; Abatement Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-02

    ... for a specific permit authorizing the use of raptors in abatement activities (76 FR 39368). The... the advance notice of proposed rulemaking, please refer to that document at 76 FR 39368 (July 6, 2011... Fish and Wildlife Service 50 CFR Part 21 RIN 1018-AW75 Migratory Bird Permits; Abatement...

  7. Partial migration: growth varies between resident and migratory fish.

    PubMed

    Gillanders, Bronwyn M; Izzo, Christopher; Doubleday, Zoë A; Ye, Qifeng

    2015-03-01

    Partial migration occurs in many taxa and ecosystems and may confer survival benefits. Here, we use otolith chemistry data to determine whether fish from a large estuarine system were resident or migratory, and then examine whether contingents display differences in modelled growth based on changes in width of otolith growth increments. Sixty-three per cent of fish were resident based on Ba : Ca of otoliths, with the remainder categorized as migratory, with both contingents distributed across most age/size classes and both sexes, suggesting population-level bet hedging. Migrant fish were in slightly better condition than resident fish based on Fulton's K condition index. Migration type (resident versus migratory) was 56 times more likely to explain variation in growth than a model just incorporating year- and age-related growth trends. While average growth only varied slightly between resident and migratory fish, year-to-year variation was significant. Such dynamism in growth rates likely drives persistence of both life-history types. The complex relationships in growth between contingents suggest that management of species exhibiting partial migration is challenging, especially in a world subject to a changing climate. PMID:25788490

  8. Desired Mobility or Satisfied Immobility? Migratory Aspirations among Knowledge Workers

    ERIC Educational Resources Information Center

    Ferro, Anna

    2006-01-01

    Among the aspects discussed within the globalisation process, the international mobility of professional workers assumes considerable relevance. This paper focuses on migratory aspirations among knowledge workers within the context of economic globalisation and market restructuring in Romania. Due to a lack of literature dealing with these issues,…

  9. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    USGS Publications Warehouse

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  10. Leadership, collective motion and the evolution of migratory strategies.

    PubMed

    Guttal, Vishwesha; Couzin, Iain D

    2011-05-01

    Migration is a hallmark life history strategy of a diverse range of organisms, and also ubiquitous in ontogenic processes including normal embryonic development as well as tumor progression. In such scenarios, individual organisms/cells typically respond to long range (and often noisy) environmental cues. In addition, individuals may interact socially with one another leading to emergent group-level navigational abilities. Although much progress has been made in understanding the mechanisms of taxis, there is a lack of theoretical and quantitative understanding of how individuals trade-off information obtained through their own migratory ability and that via social interactions. Here, we discuss results and insights from a recent computational model developed to investigate the evolution of leadership and collective motion in migratory populations. It is shown that, for a broad range of parameter values, only a small proportion of the population gather directional information while the majority employ social cues alone. More generally, ecological conditions for the evolution of resident, solitary and collective migratory strategies are obtained. We discuss how consideration of both proximate and ultimate factors within the same framework may provide insights into preserving migratory patterns that are in grave danger due to anthropogenic pressures. PMID:21980562

  11. Genetics of migratory and invasive pests in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Overview of genetic research on migratory and invasive pests being performed at CMAVE. Emphasis will be on efforts to monitor the movements of fall armyworm, Spodoptera frugiperda (J.E. Smith)(Lepidoptera: Noctuidae) during its annual migration, model the behavior in order to predict the effect of r...

  12. Do monarch butterflies use polarized skylight for migratory orientation?

    PubMed

    Stalleicken, Julia; Mukhida, Maya; Labhart, Thomas; Wehner, Rüdiger; Frost, Barrie; Mouritsen, Henrik

    2005-06-01

    To test if migratory monarch butterflies use polarized light patterns as part of their time-compensated sun compass, we recorded their virtual flight paths in a flight simulator while the butterflies were exposed to patches of naturally polarized blue sky, artificial polarizers or a sunny sky. In addition, we tested butterflies with and without the polarized light detectors of their compound eye being occluded. The monarchs' orientation responses suggested that the butterflies did not use the polarized light patterns as a compass cue, nor did they exhibit a specific alignment response towards the axis of polarized light. When given direct view of the sun, migratory monarchs with their polarized light detectors painted out were still able to use their time-compensated compass: non-clockshifted butterflies, with their dorsal rim area occluded, oriented in their typical south-southwesterly migratory direction. Furthermore, they shifted their flight course clockwise by the predicted approximately 90 degrees after being advance clockshifted 6 h. We conclude that in migratory monarch butterflies, polarized light cues are not necessary for a time-compensated celestial compass to work and that the azimuthal position of the sun disc and/or the associated light-intensity and spectral gradients seem to be the migrants' major compass cue. PMID:15939779

  13. Meeting migratory bird management needs by integrated disease control

    USGS Publications Warehouse

    Friend, M.

    1984-01-01

    The need to combat diseases of migratory birds more effectively will intensify because of need to counteract effects of continual habitat losses. Degradation of habitat will increase potential for disease transmission and the emergence of new disease problems. Migratory bird mobility provides a ready mechanism for spread of disease to locations greatly removed from the site of initial outbreaks. Disease control and management on a flyway basis is needed to combat disease problems of migratory birds more effectively. Modifications in the flyway council system are suggested for implementation of an integrated approach to disease control. Flyway management of disease problems is not a new concept and has been used for addressing lead poisoning in waterfowl (Greenwalt 1976). However, integration of disease concepts in the management of migratory birds on a flyway basis has not been attempted to the extent identified in this paper. Information and communication needs to achieve the goal of minimizing losses of migratory birds to disease are also identified. The limited resources available for disease investigations dictate that sound planning efforts serve as the foundation for program development, priority assessment, and coordination of efforts. Effective disease control in migratory birds is achievable. However, disease control will not happen without adjustments in current perspectives and approaches to disease problems. 'A prime requisite of long range planning for animal disease control or eradication is an attitude of mind that sustains an unflagging optimism toward the ultimate accomplishment of desired results, coupled with an equally persistent skepticism toward dogmatic formulae promising either certain success or certain failure. A long range plan cannot remain inviolate. It must undergo constant critical review and modification as necessary to: accommodate newly acquired scientific or practical information; meet changing economic conditions; account for

  14. Black African Traditional Mathematics

    ERIC Educational Resources Information Center

    Zaslavsky, Claudia

    1970-01-01

    Discusses the traditional number systems and the origin of the number names used by several African peoples living south of the Sahara. Also included are limitations in African mathematical development, and possible topics for research. (RP)

  15. Organochlorine insecticide residues in African Fauna: 1971-1995.

    PubMed

    Wiktelius, S; Edwards, C A

    1997-01-01

    Organochlorine insecticides (OCLs), which were introduced in the decade following World War II, were used extensively in Europe, the U.S., and other developed countries into the 1970s. However, data began to accumulate on their persistence in soils and aquatic sediments, their potential to be taken up into animal tissues and to bioconcentrate in birds and mammals in the higher tropic levels of food chains and even in humans. As a result, registration authorities phased out their use progressively, in Europe and the U.S., from 1973 onward. However, the production of OCLs in developed countries and their use in developing countries continued through the 1970s and 1980s into the 1990s because they were, no longer under patent agreement, were inexpensive to manufacture, and were very effective in pest control. In Africa, the use of OCLs continued well into the 1990s for the control of mosquitoes, tsetse flies, and desert locusts as well as to combat various crop, animal, and human pests. Some of these uses involved extensive spraying of large areas of nonagricultural land, thereby exposing many groups and species of wildlife to their residues. Although there is some evidence of a gradual decline in the use of OCLs in Africa, they are still being used in appreciable quantities. During the past 25 yr, there have been 50 published reports of OCL residues in the various groups of invertebrate and vertebrate animals constituting the African fauna. These have been based on a diverse range of surveys, target animals, sampling methods, and analytical techniques. Moreover, they are extremely regionally-biased, the most intense surveys being in Zimbabwe, Kenya, Egypt, and South Africa. DDT was the most commonly used OCL, accounting for about half the total use, followed closely by dieldrin and HCH. Birds and fish have been sampled most intensively, with relatively few studies on other taxa. We reviewed the OCL residue data on African fauna from these reports and summarized the

  16. Sun compass integration of skylight cues in migratory monarch butterflies.

    PubMed

    Heinze, Stanley; Reppert, Steven M

    2011-01-27

    Migrating monarch butterflies (Danaus plexippus) use a time-compensated sun compass to navigate from eastern North America to their overwintering grounds in central Mexico. Here we describe the neuronal layout of those aspects of the butterfly's central complex likely to establish part of the internal sun compass and find them highly homologous to those of the desert locust. Intracellular recordings from neurons in the monarch sun compass network reveal responses tuned to specific E-vector angles of polarized light, as well as azimuth-dependent responses to unpolarized light, independent of spectral composition. The neural responses to these two stimuli in individual neurons are mediated through different regions of the compound eye. Moreover, these dual responses are integrated to create a consistent representation of skylight cues in the sun compass throughout the day. The results advance our understanding of how ambiguous sensory signals are processed by the brain to elicit a robust behavioral response. PMID:21262471

  17. The African Connection

    ERIC Educational Resources Information Center

    Oguntoyinbo, Lekan

    2012-01-01

    From student and faculty exchanges to joint research projects, U.S. universities maintain a broad spectrum of collaborative relationships with African universities. It's unclear how many U.S. colleges and universities have partnerships with African universities. The African Studies Association, an organization of scholars, doesn't keep that kind…

  18. 75 FR 58993 - Migratory Bird Hunting; Late Seasons and Bag and Possession Limits for Certain Migratory Game Birds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-24

    ... published in the Federal Register (75 FR 27144) a proposal to amend 50 CFR part 20. The proposal provided a... FR 32872) a second document providing supplemental proposals for early- and late-season migratory... in the Federal Register (75 FR 44856) a third document specifically dealing with the...

  19. 75 FR 53226 - Migratory Bird Hunting; Early Seasons and Bag and Possession Limits for Certain Migratory Game...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-31

    ... published in the Federal Register (75 FR 27144) a proposal to amend 50 CFR part 20. The proposal provided a... FR 32872) a second document providing supplemental proposals for early- and late-season migratory... in the Federal Register (75 FR 44856) a third document specifically dealing with the...

  20. Impact of density and environmental factors on population fluctuations in a migratory passerine.

    PubMed

    Pasinelli, Gilberto; Schaub, Michael; Häfliger, Guido; Frey, Monika; Jakober, Hans; Müller, Mathis; Stauber, Wolfgang; Tryjanowski, Piotr; Zollinger, Jean-Luc; Jenni, Lukas

    2011-01-01

    1. Populations of plants and animals typically fluctuate because of the combined effects of density-dependent and density-independent processes. The study of these processes is complicated by the fact that population sizes are typically not known exactly, because population counts are subject to sampling variance. Although the existence of sampling variance is broadly acknowledged, relatively few studies on time-series data have accounted for it, which can result in wrong inferences about population processes. 2. To increase our understanding of population dynamics, we analysed time series from six Central European populations of the migratory red-backed shrike Lanius collurio by simultaneously assessing the strength of density dependence, process and sampling variance. In addition, we evaluated hypotheses predicting effects of factors presumed to operate on the breeding grounds, at stopover sites in eastern Africa during fall and spring migration and in the wintering grounds in southern Africa. We used both simple and state-space formulations of the Gompertz equation to model population size. 3. Across populations and modelling approaches, we found consistent evidence for negative density-dependent population regulation. Further, process variance contributed substantially to variation in population size, while sampling variance did not. Environmental conditions in eastern and southern Africa appear to influence breeding population size, as rainfall in the Sahel during fall migration and in the south African wintering areas were positively related to population size in the following spring in four of six populations. In contrast, environmental conditions in the breeding grounds were not related to population size. 4. Our findings suggest negative density-dependent regulation of red-backed shrike breeding populations and are consistent with the long-standing hypothesis that conditions in the African staging and wintering areas influence population numbers of species

  1. Oak forest exploitation and black-locust invasion caused severe shifts in epiphytic lichen communities in Northern Italy.

    PubMed

    Nascimbene, Juri; Marini, Lorenzo

    2010-10-15

    In the last two centuries, native European oak forests have undergone a dramatic decline related to increasing human pressure for agriculture and urbanization. Oak forests were either completely eradicated and transformed into agricultural landscapes or replaced by second-growth formations. Intensive forest management and the replacement of native forests with production forests or arable lands are recognized amongst the main threats to many lichens in Europe. In this study, we used historical information on the epiphytic lichen biota which was hosted in a native oak-dominated forest of Northern Italy to identify shifts of lichen communities due to the changes in land use which occurred during the last two centuries. We also compared the epiphytic lichen communities inhabiting remnant oak forests with those found in the habitats that have replaced native forests: black-locust forests and agrarian landscapes. Almost all the species sampled during the 19th century are now extinct. The loss of native habitat and the subsequent invasion by black locust were probably the most influential factors which affected the composition of lichen communities, causing the local extinction of most of the species historically recorded. Despite the fact that oak remnants host only a few species which were historically recorded, and that they currently are the lichen poorest habitat in the study region, they host lichen assemblages differing from those of black-locust forests and agrarian stands. In these habitats lichen assemblages are mainly composed of species adapted to well-lit, dry conditions and tolerating air pollution and eutrophication. This pattern is likely to be common also in other lowland and hilly regions throughout Northern Italy where oak forests are targeted among the habitats of conservation concern at the European level. For this reason, a national strategy for biodiversity conservation and monitoring of lowlands forests should provide the framework for local

  2. Knockdown of the corazonin gene reveals its critical role in the control of gregarious characteristics in the desert locust.

    PubMed

    Sugahara, Ryohei; Saeki, Shinjiro; Jouraku, Akiya; Shiotsuki, Takahiro; Tanaka, Seiji

    2015-08-01

    The two plague locusts, Schistocerca gregaria and Locusta migratoria, exhibit density-dependent phase polyphenism. Nymphs occurring at low population densities (solitarious forms) are uniformly colored and match their body color to the background color of their habitat, whereas those occurring at high population densities (gregarious) develop black patterns. An injection of the neuropeptide, corazonin (Crz) has been shown to induce black patterns in locusts and affect the classical morphometric ratio, F/C (F, hind femur length; C, maximum head width). We herein identified and cloned the CRZ genes from S. gregaria (SgCRZ) and L. migratoria. A comparative analysis of prepro-Crz sequences among insects showed that the functional peptide was well conserved; its conservation was limited to the peptide region. Silencing of the identified SgCRZ gene in gregarious S. gregaria nymphs markedly lightened their body color and shifted the adult F/C ratio toward the value typical of solitarious forms. In addition, knockdown of the gene in solitarious nymphs strongly inhibited darkening even after a transfer to crowded conditions; however, these individuals developed black patterns after being injected with the Crz as a rescue treatment. SgCRZ was constitutively expressed in the brains of S. gregaria during nymphal development in both phases. This gene was highly expressed not only in the brain in both phases, but also in the corpora allata in the gregarious phase. This conspicuous phase-dependent difference in SgCRZ gene expression may indicate a functional role in the control of phase polyphenism in this locust. PMID:26092175

  3. Neural control of gas exchange patterns in insects: locust density-dependent phases as a test case.

    PubMed

    Berman, Tali S; Ayali, Amir; Gefen, Eran

    2013-01-01

    The adaptive significance of discontinuous gas exchange cycles (DGC) in insects is contentious. Based on observations of DGC occurrence in insects of typically large brain size and often socially-complex life history, and spontaneous DGC in decapitated insects, the neural hypothesis for the evolution of DGC was recently proposed. It posits that DGC is a non-adaptive consequence of adaptive down-regulation of brain activity at rest, reverting ventilatory control to pattern-generating circuits in the thoracic ganglia. In line with the predictions of this new hypothesis, we expected a higher likelihood of DGC in the gregarious phase of the desert locust (Schistocerca gregaria, Orthoptera), which is characterized by a larger brain size and increased sensory sensitivity compared with the solitary phase. Furthermore, surgical severing of the neural connections between head and thoracic ganglia was expected to increase DGC prevalence in both phases, and to eliminate phase-dependent variation in gas exchange patterns. Using flow-through respirometry, we measured metabolic rates and gas exchange patterns in locusts at 30°C. In contrast to the predictions of the neural hypothesis, we found no phase-dependent differences in DGC expression. Likewise, surgically severing the descending regulation of thoracic ventilatory control did not increase DGC prevalence in either phase. Moreover, connective-cut solitary locusts abandoned DGC altogether, and employed a typical continuous gas exchange pattern despite maintaining metabolic rate levels of controls. These results are not consistent with the predictions of the neural hypothesis for the evolution of DGC in insects, and instead suggest neural plasticity of ventilatory control. PMID:23555850

  4. Level II scour analysis for Bridge 25 (BRNATH00290034) on Town Highway 29, crossing Locust Creek, Barnard, Vermont

    USGS Publications Warehouse

    Ivanoff, Michael A.; Weber, Matthew A.

    1996-01-01

    The Town Highway 29 crossing of Locust Creek is a 37-ft-long, one-lane bridge consisting of one 32-foot concrete span (Vermont Agency of Transportation, written communication, August 23, 1994). The bridge is supported by vertical, concrete abutments with wingwalls. The channel is skewed approximately 25 degrees to the opening while the opening-skew-to-roadway is 25 degrees. There was no observable scour protection measure at the site. Additional details describing conditions at the site are included in the Level II Summary and Appendices D and E.

  5. Rheological and kinetic study of the ultrasonic degradation of locust bean gum in aqueous saline and salt-free solutions.

    PubMed

    Li, Ruoshi; Feke, Donald L

    2015-11-01

    The ultrasonic degradation of locust bean gum (LBG) in aqueous solutions has been studied at 25°C for ultrasonication times up to 120 min. Although LBG is not a polyelectrolyte, the degradation extent and kinetics were found to be somewhat sensitive to the ionic conditions in solution, and this is attributed to changes in molecular conformation that can occur in different salt environments. Ultrasonic degradation was tracked by rheological measurements that lead to the determination of intrinsic viscosity for the LBG molecules. A kinetic model was also developed and successfully applied to characterize and predict the degradation results. PMID:26186852

  6. Development and deposition of resilin in energy stores for locust jumping.

    PubMed

    Burrows, Malcolm

    2016-08-15

    Locusts jump by using a catapult mechanism in which energy produced by slow contractions of the extensor tibiae muscles of the hind legs is stored in distortions of the exoskeleton, most notably (1) the two semi-lunar processes at each knee joint and (2) the tendons of the extensor muscles themselves. The energy is then suddenly released from these stores to power the rapid, propulsive movements of the hind legs. The reliance on the mechanical storage of energy is likely to impact on jumping because growth occurs by a series of five moults, at each of which the exoskeleton is replaced by a new one. All developmental stages (instars) nevertheless jump as a means of forward locomotion, or as an escape movement. Here, I show that in each instar, resilin is added to the semi-lunar processes and to the core of the extensor tendons so that their thickness increases. As the next moult approaches, a new exoskeleton forms within the old one, with resilin already present in the new semi-lunar processes. The old exoskeleton, the tendons and their resilin are discarded at moulting. The resilin of the semi-lunar processes and tendons of the new instar is initially thin, but a similar pattern of deposition results in an increase of their thickness. In adults, resilin continues to be deposited so that at 4 weeks old the thickness in the semi-lunar processes has increased fourfold. These changes in the energy stores accompany changes in jumping ability and performance during each moulting cycle. PMID:27259374

  7. Loss of potassium homeostasis underlies hyperthermic conduction failure in control and preconditioned locusts.

    PubMed

    Money, Tomas G A; Rodgers, Corinne I; McGregor, Stuart M K; Robertson, R Meldrum

    2009-07-01

    At extreme temperature, neurons cease to function appropriately. Prior exposure to a heat stress (heat shock [HS]) can extend the temperature range for action potential conduction in the axon, but how this occurs is not well understood. Here we use electrophysiological recordings from the axon of a locust visual interneuron, the descending contralateral movement detector (DCMD), to examine what physiological changes result in conduction failure and what modifications allow for the observed plasticity following HS. We show that at high temperature, conduction failure in the DCMD occurred preferentially where the axon passes through the thoracic ganglia rather than in the connective. Although the membrane potential hyperpolarized with increasing temperature, we observed a modest depolarization (3-6 mV) in the period preceding the failure. Prior to the conduction block, action potential amplitude decreased and half-width increased. Both of these failure-associated effects were attenuated following HS. Extracellular potassium concentration ([K+]o) increased sharply at failure and the failure event could be mimicked by the application of high [K+]o. Surges in [K+]o were muted following HS, suggesting that HS may act to stabilize ion distribution. Indeed, experimentally increased [K+]o lowered failure temperature significantly more in control animals than in HS animals and experimentally maintained [K+]o was found to be protective. We suggest that the more attenuated effects of failure on the membrane properties of the DCMD axon in HS animals is consistent with a decrease in the disruptive nature of the [K+]o-dependent failure event following HS and thus represents an adaptive mechanism to cope with thermal stress. PMID:19386751

  8. Black locust--successful invader of a wide range of soil conditions.

    PubMed

    Vítková, Michaela; Tonika, Jaroslav; Müllerová, Jana

    2015-02-01

    Black locust (Robinia pseudoacacia, BL), a species native to North America, has successfully invaded many types of habitats over the world. This study provides an overall assessment of BL soil conditions to determine the range of physical-chemical soil properties it can tolerate. 511 BL stands (for the soil types) and 33 permanent plots (for the soil chemistry) were studied in the Czech Republic. Relationships among different environmental variables (physical-chemical soil properties, vegetation characteristics and habitat conditions) were investigated and variables with the highest effect on species composition were detected. The results were compared with data in the literature for other parts of the secondary and native distributions of this species. This assessment showed that BL is able to tolerate extremely diverse soil physical-chemical conditions, from extremely acid to strongly alkaline, and from medium to highly base saturated soils with a gradient of different subsurface stoniness. Soil nitrate, N mineralization and nitrification rates also varied considerably and the concentrations of exchangeable phosphorus and ammonium were consistently low. N mineralization rate, incubated inorganic nitrogen and nitrates were positively correlated with base saturation and cation exchange capacity. The most common soil types were young soils (Cambisols, Leptosols, Arenosols, and coarsely textured Fluvisols). BL seems to be limited by water supply and soil aeration and prefers well aerated and drained soils, and tolerates desiccation but avoids compact soils and areas where the soils are frequently waterlogged. On steep slopes, BL was less vigorous, stunted and less competitive. By contrast, the tallest BL trees were found on sandy soils in a flat landscape. Number and share of nitrophytes in the herb layer were positively related to basic bedrock, soil reaction and N-NO3/N ratio. Soil reaction was determined as the most important environmental characteristic

  9. Fluoride blocks an inactivation step of transduction in a locust photoreceptor

    PubMed Central

    Payne, Richard

    1982-01-01

    1. Photoreceptors in a superfused retina of a locust compound eye are treated with saline containing 10 mM-NaF, while their intracellular resting potential and responses are recorded using glass micropipettes. 2. Treatment for two minutes with 10 mM-NaF, followed by a series of brief, bright flashes of light, results in an irreversible, noisy depolarization of approximately 10 mV. The final, stable level of depolarization is reached through the summed effect of each of the noisy, depolarizing afterpotentials that follow every response of the cell to a light flash. If kept in darkness after treatment with NaF, the noisy depolarization still develops, but more gradually, over a period of 5 min. 3. The voltage noise induced by NaF mimics light-induced voltage noise when the two are compared at mean depolarizations of more than 15 mV. At very small depolarizations, however, fluoride-induced noise cannot be resolved into the large discrete events (bumps) that are typical of the response of a dark-adapted photoreceptor to a single photon. 4. The complete replacement of the superfusate sodium by choline reversibly reduces the fluoride-induced noise and depolarization to the same extent as it does the light-induced noise and depolarization of an illuminated cell. 5. Increasing the superfusate calcium concentration from 0·5 to 10 mM also reversibly reduces fluoride-induced noise and depolarization to the same extent as it does light-induced noise and depolarization. This action of calcium is accompanied by an increase in a cell's input resistance which opposes the reduction caused by light or fluoride treatment. 6. The results confirm the proposal (Payne, 1981) that anionic metabolic inhibitors cause spontaneous activity in sodium channels that are normally opened by light. A model is proposed in which fluoride acts by blocking the inactivation of a late stage in the transduction mechanism. PMID:6286940

  10. Proctolin degradation by membrane peptidases from nervous tissues of the desert locust (Schistocerca gregaria).

    PubMed

    Isaac, R E

    1987-07-15

    The hydrolysis of the insect neuropeptide proctolin (Arg-Tyr-Leu-Pro-Thr) by enzyme preparations from the nervous tissue of the desert locust (Schistocerca gregaria) was investigated. Neural homogenate degraded proctolin (100 microM) at neutral pH by cleavage of the Arg-Tyr and Tyr-Leu bonds to yield Tyr-Leu-Pro-Thr, Arg-Tyr and free tyrosine. Arg-Tyr was detected as a major metabolite when the aminopeptidase inhibitors amastatin and bestatin were present to prevent Arg-Tyr breakdown. Around 50% of the proctolin-degrading activity was isolated in a 30,000 g membrane fraction and was shown to be almost entirely due to aminopeptidase activity. The aminopeptidase had an apparent Km of 23 microM, a pH optimum of 7.0 and was inhibited by 1 mM-EDTA and amastatin [IC50 = 0.3 microM], but was relatively insensitive to bestatin, actinonin and puromycin. Phenylmethanesulphonyl fluoride (1 mM) and p-chloromercuriphenylsulphonic acid (1 mM) had no effect on this enzyme activity. Although the bulk of the Tyr-Leu hydrolytic activity was located in the 30,000 g supernatant, some weak activity was detected in a washed membrane preparation. This peptidase displayed a high affinity for proctolin (Km = 0.35 microM) and optimal activity at around pH 7.0. Synaptosome- and mitochondria-rich fractions were prepared from crude neural membranes. The aminopeptidase activity was concentrated in the synaptic-membrane preparation, whereas activity giving rise to Arg-Tyr was predominantly localized in the mitochondrial fraction. The subcellular localization of the membrane aminopeptidase is consistent with a possible physiological role for this enzyme in the inactivation of synaptically released proctolin. PMID:2889451

  11. Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish.

    PubMed

    Chapman, Ben B; Hulthén, Kaj; Brönmark, Christer; Nilsson, P Anders; Skov, Christian; Hansson, Lars-Anders; Brodersen, Jakob

    2015-09-01

    1. Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body morphology can be explained by variation in migratory strategy within a species. 2. We address this question in roach Rutilus rutilus, a partially migratory freshwater fish that migrates from lakes into streams during winter. We both compare body shape between populations that differ in migratory opportunity (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. 3. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow-bodied morphology than fish from closed lakes and all-year residents. 4. Our data suggest that a shallow body morphology is beneficial to migratory individuals and our study is one of the first to link migratory strategy and intraspecific variation in body shape. PMID:25823702

  12. Possibly drug-induced palpable migratory arciform erythema*

    PubMed Central

    Dantas, Fernando Luiz Teixeira; Valente, Neusa Yuriko Sakai; Veronez, Isis Suga; Kakizaki, Priscila; Leitão, Juliana Ribeiro; Fraga, Rafael Cavanellas

    2015-01-01

    Palpable migratory arciform erythema is an entity of unknown etiology, with few published cases in the literature. The clinical and histopathological features of this disease are difficult to be distinguished from those of Jessner’s lymphocytic infiltration of the skin, lupus erythematous tumidus and the deep erythema annulare centrifugum. We describe here the first two Brazilian cases of palpable migratory arciform erythema. The patients presented with infiltrated annular plaques and erythematous arcs without scales. These showed centrifugal growth before disappearing without scarring or residual lesions after a few days. They had a chronic course with repeated episodes for years. In addition, these cases provide evidence of a drug-induced etiology. PMID:26312680

  13. 78 FR 68757 - Atlantic Highly Migratory Species; Vessel Monitoring Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-15

    ...NMFS is modifying the reporting requirements for vessels required to use Vessel Monitoring System (VMS) units in Atlantic Highly Migratory Species (HMS) fisheries. This final rule requires vessel owners or operators, who have been issued HMS permits and are required to use VMS, to provide hourly position reports 24 hours a day, 7 days a week (24/7) via VMS. The final rule also allows the......

  14. The Geographical Distribution Of The Black Locust (Robinia Pseudoacacia L.) In Poland And Its Role On Non-Forest Land

    NASA Astrophysics Data System (ADS)

    Wojda, Tomasz; Klisz, Marcin; Jastrzębowski, Szymon; Mionskowski, Marcin; Szyp-Borowska, Iwona; Szczygieł, Krystyna

    2015-01-01

    The black locust (Robinia pseudoacacia L.) has been present in Poland for more than 200 years now, its range coming to encompass the entire country, albeit with a particular concentration of occurrence in the west. Overall, it is present in 3.4% of the stands making up Poland's "State Forests National Forest Holding" (Państwowe Gospodarstwo Leśne Lasy Państwowe), and is the dominant species in 0.1% of stands. Thanks to its producing durable wood of favourable energetic properties, this species is used in medium-rotation (≤ 40-year) plantations as well as in biomass energy plantations (where there is a 5-7-year rotation). In terms of its nectar production, the black locust is second only to lime as the Polish tree best serving the production of honey. While the species shows marked expansiveness in Poland, it has not thus far been placed on the list of aliens capable of threatening native species or natural habitats. Breeding of the species has been engaged in - if to only a limited extent - in Poland for some 20 years now, and 2 selected seed stands have been registered, as well as 34 plus trees and 2 seed orchards.

  15. Proctolin in the innervation of the locust mandibular closer muscle modulates contractions through the elevation of inositol trisphosphate.

    PubMed

    Baines, R A; Lange, A B; Downer, R G

    1990-07-22

    Extracts of the locust (Locusta migratoria) mandibular closer muscle separated on reverse-phase HPLC and tested for bio-activity on the locust oviduct contain a bio-active substance that coelutes with authentic proctolin. Furthermore, the effect on oviduct contractions of this compound is indistinguishable from that of authentic proctolin. Antiserum to proctolin stains numerous axons with beaded endings that run along the fibres of the closer muscles and, in addition, the antiserum stains a number of cell bodies in the suboesophageal ganglion, some of which have axons in the mandibular nerve that innervates the mandibular musculature. The function of proctolin appears to be modulatory as its presence significantly increases the amplitude of neurally evoked contractions of the closer muscle. This effect can be mimicked by the addition of inositol 1,4,5-trisphosphate (IP3) to preparations in which the muscles have been permeabilized with dimethyl sulfoxide. The involvement of this second messenger is further implicated as we also show that proctolin produces a large, significant increase in the IP3 content of homogenized muscle. PMID:1974556

  16. Identification of distinct tyraminergic and octopaminergic neurons innervating the central complex of the desert locust, Schistocerca gregaria

    PubMed Central

    Homberg, Uwe; Seyfarth, Jutta; Binkle, Ulrike; Monastirioti, Maria; Alkema, Mark J.

    2012-01-01

    The central complex is a group of modular neuropils in the insect brain with a key role in visual memory, spatial orientation, and motor control. In desert locusts the neurochemical organization of the central complex has been investigated in detail, including the distribution of dopamine-, serotonin-, and histamine-immunoreactive neurons. In the present study we identified neurons immunoreactive with antisera against octopamine, tyramine, and the enzymes required for their synthesis, tyrosine decarboxylase (TDC) and tyramine β-hydroxylase (TBH). Octopamine- and tyramine immunostaining in the central complex differed strikingly. In each brain hemisphere tyramine immunostaining was found in four neurons innervating the noduli, 12–15 tangential neurons of the protocerebral bridge, and about 17 neurons that supplied the anterior lip region and parts of the central body. In contrast, octopamine immunostaining was present in two bilateral pairs of ascending fibers innervating the upper division of the central body and a single pair of neurons with somata near the oesophageal foramen that gave rise to arborizations in the protocerebral bridge. Immunostaining for TDC, the enzyme converting tyrosine to tyramine, combined the patterns seen with the tyramine- and octopamine antisera. Immunostaining for TBH, the enzyme converting tyramine to octopamine, in contrast, was strikingly similar to octopamine immunolabeling. We conclude that tyramine and octopamine act as neurotransmitters/modulators in distinct sets of neurons of the locust central complex with TBH likely being the rate limiting enzyme for octopamine synthesis in a small subpopulation of TDC-containing neurons. PMID:23595814

  17. Identification of outliers in a genomic scan for selection along environmental gradients in the bamboo locust, Ceracris kiangsu.

    PubMed

    Feng, Xiao-Jing; Jiang, Guo-Fang; Fan, Zhou

    2015-01-01

    Identification of loci under divergent selection is a key step in understanding the evolutionary process because those loci are responsible for the genetic variations that affect fitness in different environments. Understanding how environmental forces give rise to adaptive genetic variation is a challenge in pest control. Here, we performed an amplified fragment length polymorphism (AFLP) genome scan in populations of the bamboo locust, Ceracris kiangsu, to search for candidate loci that are influenced by selection along an environmental gradient in southern China. In outlier locus detection, loci that demonstrate significantly higher or lower among-population genetic differentiation than expected under neutrality are identified as outliers. We used several outlier detection methods to study the features of C. kiangsu, including method DFDIST, BayeScan, and logistic regression. A total of 97 outlier loci were detected in the C. kiangsu genome with very high statistical supports. Moreover, the results suggested that divergent selection arising from environmental variation has been driven by differences in temperature, precipitation, humidity and sunshine. These findings illustrate that divergent selection and potential local adaptation are prevalent in locusts despite seemingly high levels of gene flow. Thus, we propose that native environments in each population may induce divergent natural selection. PMID:26333424

  18. Chemical identification, emission pattern and function of male-specific pheromones released by a rarely swarming locust, Schistocerca americana.

    PubMed

    Stahr, Christiane; Svatoš, Aleš; Seidelmann, Karsten

    2013-01-01

    Pheromones serve key functions in the biology of swarming locusts. However, research has focused largely on the mass-swarming desert locust, Schistocerca gregaria. We extended these investigations to the pheromonal profile of the rarely swarming American bird grasshopper, S. americana (Drury). The headspace of mature gregarious S. americana males contained three characteristic electroantennogram-active components: (Z)-3-nonen-1-ol, (Z)-2-octen-1-ol, and nonanal. These substances were accompanied by aromatics such as phenol that are also released by females and immatures. Male-specific pheromone components were released independently from epidermal gland cells, with the highest emission rate being for (Z)-3-nonen-1-ol from the abdomen and legs. The emission of the major compound, (Z)-3-nonen-1-ol, is stress-sensitive, and coincides with sexual maturity and crowding. The emission pattern strongly supports a role of (Z)-3-nonen-1-ol in the reproductive biology of S. americana. The pheromone is involved in courtship-inhibition and is used as mate assessment pheromone in cryptic female choice. In double mating experiments, females choose sperm of males with high (Z)-3-nonen-1-ol emission. Furthermore the pheromone accelerated maturation of immature adults and supports synchronization of sexual development. PMID:23274851

  19. Physiological and Proteomic Responses of Diploid and Tetraploid Black Locust (Robinia pseudoacacia L.) Subjected to Salt Stress

    PubMed Central

    Wang, Zhiming; Wang, Mingyue; Liu, Likun; Meng, Fanjuan

    2013-01-01

    Tetraploid black locust (Robinia pseudoacacia L.) is adaptable to salt stress. Here, we compared morphological, physiological, ultrastructural, and proteomic traits of leaves in tetraploid black locust and its diploid relatives under salt stress. The results showed that diploid (2×) plants suffered from greater negative effects than those of tetraploid (4×) plants. After salt treatment, plant growth was inhibited, photosynthesis was reduced, reactive oxygen species, malondialdehyde content, and relative electrolyte leakage increased, and defense-related enzyme activities decreased in 2× compared to those in 4×. In addition, salt stress resulted in distorted chloroplasts, swollen thylakoid membranes, accumulation of plastoglobules, and increased starch grains in 2× compared to those in 4×. However, 4× developed diverse responses under salt stress. A comparative proteomic analysis revealed that 41 and 37 proteins were differentially expressed in 2× and 4×, respectively. These proteins were mainly involved in photosynthesis, stress and defense, energy, metabolism, transcription/translation, and transportation. Distinct patterns of protein changes between 2× and 4× were analyzed. Collectively, our results suggest that the plants showed significantly different responses to salt stress based on ploidy level of the plant. The 4× possessed a better salt protection mechanism than that of 2×, suggesting salt tolerance in the polyploid plant. PMID:24129170

  20. Na+-K+-ATPase trafficking induced by heat shock pretreatment correlates with increased resistance to anoxia in locusts

    PubMed Central

    Hou, Nicholas; Armstrong, Gary A. B.; Chakraborty-Chatterjee, Munmun; Sokolowski, Marla B.

    2014-01-01

    The sensitivity of insect nervous systems to anoxia can be modulated genetically and pharmacologically, but the cellular mechanisms responsible are poorly understood. We examined the effect of a heat shock pretreatment (HS) on the sensitivity of the locust (Locusta migratoria) nervous system to anoxia induced by water immersion. Prior HS made locusts more resistant to anoxia by increasing the time taken to enter a coma and by reducing the time taken to recover the ability to stand. Anoxic comas were accompanied by surges of extracellular potassium ions in the neuropile of the metathoracic ganglion, and HS reduced the time taken for clearance of excess extracellular potassium ions. This could not be attributed to a decrease in the activity of protein kinase G, which was increased by HS. In homogenates of the metathoracic ganglion, HS had only a mild effect on the activity of Na+-K+-ATPase. However, we demonstrated that HS caused a threefold increase in the immunofluorescent localization of the α-subunit of Na+-K+-ATPase in metathoracic neuronal plasma membranes relative to background labeling of the nucleus. We conclude that HS induced trafficking of Na+-K+-ATPase into neuronal plasma membranes and suggest that this was at least partially responsible for the increased resistance to anoxia and the increased rate of recovery of neural function after a disturbance of K+ homeostasis. PMID:24848469

  1. Molecular cloning and expression analysis of the MTN gene during adventitious root development in IBA-induced tetraploid black locust.

    PubMed

    Quan, Jine; Zhang, Chunxia; Zhang, Sheng; Meng, Sen; Zhao, Zhong; Xu, Xuexuan

    2014-12-15

    5'-Methylthioadenosine (MTA) nucleosidase (MTN) plays a key role in the methionine (Met) recycling pathway of plants. Here, we report the isolation of the 1158 bp full-length, cDNA sequence encoding tetraploid black locust (Robinia pseudoacacia L.) MTN (TrbMTN), which contains an open reading frame of 810 bp that encodes a 269 amino acid protein. The amino acid sequence of TrbMTN has more than 88% sequence identity to the MTNs from other plants, with a closer phylogenetic relationship to MTNs from legumes than to MTNs from other plants. Subcellular localization analysis revealed that the TrbMTN gene localizes mainly to the cell membrane and cytoplasm of onion epidermal cells. Indole-3-butyric acid (IBA)-treated cuttings showed higher TrbMTN transcript levels than untreated control cuttings during root primordium and adventitious root formation. TrbMTN and key Met cycle genes showed differential expression in shoots, leaves, stems, and roots, with the highest expression observed in stems. IBA-treated cuttings also showed higher TrbMTN activity than control cuttings during root primordium and adventitious root formation. These results indicate that TrbMTN gene might play an important role in the regulation of IBA-induced adventitious root development in tetraploid black locust cuttings. PMID:25305345

  2. Tomographic particle image velocimetry of desert locust wakes: instantaneous volumes combine to reveal hidden vortex elements and rapid wake deformation

    PubMed Central

    Bomphrey, Richard J.; Henningsson, Per; Michaelis, Dirk; Hollis, David

    2012-01-01

    Aerodynamic structures generated by animals in flight are unstable and complex. Recent progress in quantitative flow visualization has advanced our understanding of animal aerodynamics, but measurements have hitherto been limited to flow velocities at a plane through the wake. We applied an emergent, high-speed, volumetric fluid imaging technique (tomographic particle image velocimetry) to examine segments of the wake of desert locusts, capturing fully three-dimensional instantaneous flow fields. We used those flow fields to characterize the aerodynamic footprint in unprecedented detail and revealed previously unseen wake elements that would have gone undetected by two-dimensional or stereo-imaging technology. Vortex iso-surface topographies show the spatio-temporal signature of aerodynamic force generation manifest in the wake of locusts, and expose the extent to which animal wakes can deform, potentially leading to unreliable calculations of lift and thrust when using conventional diagnostic methods. We discuss implications for experimental design and analysis as volumetric flow imaging becomes more widespread. PMID:22977102

  3. Identification of outliers in a genomic scan for selection along environmental gradients in the bamboo locust, Ceracris kiangsu

    PubMed Central

    Feng, Xiao-Jing; Jiang, Guo-Fang; Fan, Zhou

    2015-01-01

    Identification of loci under divergent selection is a key step in understanding the evolutionary process because those loci are responsible for the genetic variations that affect fitness in different environments. Understanding how environmental forces give rise to adaptive genetic variation is a challenge in pest control. Here, we performed an amplified fragment length polymorphism (AFLP) genome scan in populations of the bamboo locust, Ceracris kiangsu, to search for candidate loci that are influenced by selection along an environmental gradient in southern China. In outlier locus detection, loci that demonstrate significantly higher or lower among-population genetic differentiation than expected under neutrality are identified as outliers. We used several outlier detection methods to study the features of C. kiangsu, including method DFDIST, BayeScan, and logistic regression. A total of 97 outlier loci were detected in the C. kiangsu genome with very high statistical supports. Moreover, the results suggested that divergent selection arising from environmental variation has been driven by differences in temperature, precipitation, humidity and sunshine. These findings illustrate that divergent selection and potential local adaptation are prevalent in locusts despite seemingly high levels of gene flow. Thus, we propose that native environments in each population may induce divergent natural selection. PMID:26333424

  4. Low-fat sodium-reduced sausages: Effect of the interaction between locust bean gum, potato starch and κ-carrageenan by a mixture design approach.

    PubMed

    García-García, Elizabeth; Totosaus, Alfonso

    2008-04-01

    A mixture design approach was used to evaluate interactions between potato starch, locust bean gum and κ-carrageenan and their effect on cooking yield, expressible moisture, texture and color in low-fat sodium-reduced sausages formulated with potassium and calcium chloride. Starch had a notable influence on cooking yield and texture, increasing product hardness and resilience as starch proportion increased. The added salt did not allow complete starch granule gelatinization and swelling, which negatively affected water retention, cohesiveness and lightness. Locust bean gum and κ-carrageenan improved cooking yield and reduced expressible moisture in formulations containing higher proportions of potato starch. The presence of other ions could have enhanced κ-carrageenan functionality and its synergistic interaction with locust bean gum, improving texture and water retention, with only minor effects on sausage color. At the lower tested proportions starch can be used as an extender in low-fat cooked meat products if κ-carrageenan and locust bean gum are included in similar proportions. PMID:22062459

  5. Multilocus sequence typing of Metarhizium anisopliae var acridum isolates as microbial agents for locust and grasshopper control. Genbank Accession numbers FJ787311 to FJ787325

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing interest in the biological control of locusts and grasshoppers (Acrididae) has led to the development of biopesticides based on naturally occurring pathogens which offers an environmentally safe alternative to chemical pesticides. However, the fungal strains which are being sought for biop...

  6. Application of sugar maple and black locust to the biomass/energy-plantation concept. Annual report, March 1, 1981-February 28, 1982

    SciTech Connect

    Sajdak, R.L.

    1982-03-01

    The purpose of this research program is to determine the feasibility of converting existing pole-size maple stands to biomass/energy plantations using black locust as an interplanted species. Methods to quantify biomass production in northern hardwood stands have been refined and additional sites have been sampled. Hardwood sprout biomass production was shown to be greatly affected by site, fertilizer treatment, and tree species. Screening of black locust Rhizobium strains for acid tolerance has been completed. Seven strains have been found to be tolerant of both high aluminum and low pH conditions. A greenhouse and outplanting study testing the competitiveness and nitrogen-fixing ability of these strains under forest conditions has begun. Second year results of black locust provenance testing has shown frost hardiness variation among trees to be greater than among sources. Consequently, present work is now concentrated on propagating northern locust sources vegetatively. Biomass characterization of young northern hardwood sprouts by chemical and thermal analysis is complete.

  7. Diet drives the collective migrations and affects the immunity of Mormon crickets and locusts: A comparison of these potential superspreaders of disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The need for resources is a major driver of animal migration and yet migration itself is energetically demanding. Mormon crickets and nymphal locusts readily engage in cannibalistic attacks that result in aligned, coordinated movement of individuals in massive bands that march daily for weeks at a ...

  8. Angioplastic necrolytic migratory erythema. Unique association of necrolytic migratory erythema, extensive angioplasia, and high molecular weight glucagon-like polypeptide

    SciTech Connect

    Franchimont, C.; Pierard, G.E.; Luyckx, A.S.; Gerard, J.; Lapiere, C.M.

    1982-12-01

    A diabetic patient developed necrolytic migratory erythema with extensive angioplasia and high molecular weight glucagon-like polypeptide. There was no associated neoplasm such as glucagonoma. Lesions in the skin were studied by standard optical microscopy and by radioautography after incorporation of tritiated thymidine. Alterations in the skin begin as focal necrosis in the epidermis and in epithelial structures of adnexa, followed by marked angioplasia and a superficial and deep perivascular dermatitis.

  9. African and non-African admixture components in African Americans and an African Caribbean population.

    PubMed

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  10. Opsin expression, physiological characterization and identification of photoreceptor cells in the dorsal rim area and main retina of the desert locust, Schistocerca gregaria.

    PubMed

    Schmeling, Fabian; Wakakuwa, Motohiro; Tegtmeier, Jennifer; Kinoshita, Michiyo; Bockhorst, Tobias; Arikawa, Kentaro; Homberg, Uwe

    2014-10-01

    For compass orientation many insects rely on the pattern of sky polarization, but some species also exploit the sky chromatic contrast. Desert locusts, Schistocerca gregaria, detect polarized light through a specialized dorsal rim area (DRA) in their compound eye. To better understand retinal mechanisms underlying visual navigation, we compared opsin expression, spectral and polarization sensitivities and response-stimulus intensity functions in the DRA and main retina of the locust. In addition to previously characterized opsins of long-wavelength-absorbing (Lo1) and blue-absorbing visual pigments (Lo2), we identified an opsin of an ultraviolet-absorbing visual pigment (LoUV). DRA photoreceptors exclusively expressed Lo2, had peak spectral sensitivities at 441 nm and showed high polarization sensitivity (PS 1.3-31.7). In contrast, ommatidia in the main eye co-expressed Lo1 and Lo2 in five photoreceptors, expressed Lo1 in two proximal photoreceptors, and Lo2 or LoUV in one distal photoreceptor. Correspondingly, we found broadband blue- and green-peaking spectral sensitivities in the main eye and one narrowly tuned UV peaking receptor. Polarization sensitivity in the main retina was low (PS 1.3-3.8). V-log I functions in the DRA were steeper than in the main retina, supporting a role in polarization vision. Desert locusts occur as two morphs, a day-active gregarious and a night-active solitarious form. In solitarious locusts, sensitivities in the main retina were generally shifted to longer wavelengths, particularly in ventral eye regions, supporting a nocturnal lifestyle at low light levels. The data support the role of the DRA in polarization vision and suggest trichromatic colour vision in the desert locust. PMID:25104757

  11. The African superswell

    NASA Technical Reports Server (NTRS)

    Nyblade, Andrew A.; Robinson, Scott W.

    1994-01-01

    Maps of residual bathymetry in the ocean basins around the African continent reveal a broad bathymetric swell in the southeastern Atlantic Ocean with an amplitude of about 500 m. We propose that this region of anomalously shallow bathymetry, together with the contiguous eastern and southern African plateaus, form a superswell which we refer to as the African superswell. The origin of the African superswell is uncertain. However, rifting and volcanism in eastern Africa, as well as heat flow measurements in southern Africa and the southeastern Atlantic Ocean, suggest that the superswell may be attributed, at least in part, to heating of the lithosphere.

  12. 76 FR 25306 - Proposed Information Collection; Comment Request; Highly Migratory Species Vessel Logbooks and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ... of Atlantic ] swordfish, sharks, billfish, and tunas in relation to the quotas, thereby ensuring that... migratory species, dolphin, and wahoo in each fishery. International stock assessments for tunas,...

  13. Modeling vector-borne disease risk in migratory animals under climate change.

    PubMed

    Hall, Richard J; Brown, Leone M; Altizer, Sonia

    2016-08-01

    Recent theory suggests that animals that migrate to breed at higher latitudes may benefit from reduced pressure from natural enemies, including pathogens ("migratory escape"), and that migration itself weeds out infected individuals and lowers infection prevalence ("migratory culling"). The distribution and activity period of arthropod disease vectors in temperate regions is expected to respond rapidly to climate change, which could reduce the potential for migratory escape. However, climate change could have the opposite effect of reducing transmission if differential responses in the phenology and distribution of migrants and disease vectors reduce their overlap in space and time. Here we outline a simple modeling framework for exploring the influence of climate change on vector-borne disease dynamics in a migratory host. We investigate two scenarios under which pathogen transmission dynamics might be mediated by climate change: (1) vectors respond more rapidly than migrants to advancing phenology at temperate breeding sites, causing peak susceptible host density and vector emergence to diverge ("migratory mismatch") and (2) reduced migratory propensity allows increased nonbreeding survival of infected hosts and larger breeding-site epidemics (loss of migratory culling, here referred to as "sedentary amplification"). Our results highlight the need for continued surveillance of climate-induced changes to migratory behavior and vector activity to predict pathogen prevalence and its impacts on migratory animals. PMID:27252225

  14. The efficiency of a flight muscle from the locust Schistocerca americana.

    PubMed Central

    Josephson, R K; Stevenson, R D

    1991-01-01

    1. The efficiency of the metathoracic tergosternal muscle of the locust Schistocerca americana was examined by simultaneously measuring work output from the muscle and oxygen consumption by the muscle. The work output was determined using the work-loop technique in which the muscle is subjected to periodic strain and to phasic stimulation in the strain cycle. The area of the loop formed by plotting muscle force against muscle length over a cycle is the net work output for that cycle. 2. The tergosternal muscle is a synchronous, parallel-fibred muscle containing two motor units with similar contraction kinetics. The average twitch rise time (30 degrees C) was 15 ms, the twitch duration (to 50% relaxation) was 26 ms, and the peak twitch tension with both units active was 73 kN m-2. The maximum mechanical power output during sinusoidal shortening at 20 Hz with both motor units active and stimulated once per cycle averaged 37 W kg-1. 3. The overall efficiency of the tergosternal muscle averaged 6.4% (range 4-10%) where efficiency is defined as the ratio of the net work done (20 Hz sinusoidal strain, 1 stimulus per cycle, optimum strain amplitude and stimulus phase) to the caloric equivalent of the oxygen consumed. The efficiency was independent of the duration of the test period (examined range = 10-30 s) and the same when both motor units were active as when only one was stimulated. 4. Stimulating the muscle with two stimuli per cycle (interstimulus interval = 6 ms) increased the work per cycle by about 13% above that with single stimuli per cycle, but the muscle fatigued more rapidly and after 15-25 s the power output was less with two stimuli per cycle than with one. The efficiency with two stimuli per cycle was slightly less than that with one shock per cycle. 5. The oxygen consumption during normal work cycles at 20 Hz with optimum stimulus phase and strain was greater by about 15% than the oxygen consumption during isometric contractions at the same frequency

  15. Selective actions of Lynx proteins on different nicotinic acetylcholine receptors in the locust, Locusta migratoria manilensis.

    PubMed

    Wang, Xin; Bao, Haibo; Sun, Huahua; Zhang, Yixi; Fang, Jichao; Liu, Qinghong; Liu, Zewen

    2015-08-01

    Nicotinic acetylcholine receptors (nAChRs) are major neurotransmitter receptors and targets of neonicotinoid insecticides in the insect nervous system. The full function of nAChRs is often dependent on associated proteins, such as chaperones, regulators and modulators. Here, three Lynx (Ly-6/neurotoxin) proteins, Loc-lynx1, Loc-lynx2 and Loc-lynx3, were identified in the locust, Locusta migratoria manilensis. Co-expression with Lynx resulted in a dramatic increase in agonist-evoked macroscopic currents on nAChRs Locα1/β2 and Locα2/β2 in Xenopus oocytes, but no changes in agonist sensitivity. Loc-lynx1 and Loc-lynx3 only modulated nAChRs Locα1/β2 while Loc-lynx2 modulated Locα2/β2 specifically. Meanwhile, Loc-lynx1 induced a more significant increase in currents evoked by imidacloprid and epibatidine than Loc-lynx3, and the effects of Loc-lynx1 on imidacloprid and epibatidine were significantly higher than those on acetylcholine. Among three lynx proteins, only Loc-lynx1 significantly increased [(3) H]epibatidine binding on Locα1/β2. The results indicated that Loc-lynx1 had different modulation patterns in nAChRs compared to Loc-lynx2 and Loc-lynx3. Taken together, these findings indicated that three Lynx proteins were nAChR modulators and had selective activities in different nAChRs. Lynx proteins might display their selectivities from three aspects: nAChR subtypes, various agonists and different modulation patterns. Insect Lynx (Ly-6/neurotoxin) proteins act as the allosteric modulators on insect nicotinic acetylcholine receptors (nAChRs), the important targets of insecticides. We found that insect lynx proteins showed their selectivities from at least three aspects: nAChR subtypes, various agonists and different modulation patterns. PMID:25951893

  16. Odorant-induced oscillations in the mushroom bodies of the locust.

    PubMed

    Laurent, G; Naraghi, M

    1994-05-01

    Kenyon cells are the intrinsic interneurons of the mushroom bodies in the insect brain, a center for olfactory and multimodal processing and associative learning. These neurons are small (3-8 microns soma diameter) and numerous (340,000 and 400,000 in the bee and cockroach brains, respectively). In Drosophila, Kenyon cells are the dominant site of expression of the dunce, DC0, and rutabaga gene products, enzymes in the cAMP cascade whose absence leads to specific defects in olfactory learning. In honeybees, the volume of the mushroom body neurophils may depend on the age or social status of the individual. Although the anatomy of these neurons has been known for nearly a century, their physiological properties and the principles of information processing in the circuits that they form are totally unknown. This article provides a first such characterization. The activity of Kenyon cells was recorded in vivo from locust brains with intracellular and local field potential electrodes during olfactory processing. Kenyon cells had a high input impedance (approximately 1 G omega at the soma). They produced action potentials upon depolarization, and consistently showed spike adaptation during long depolarizing current pulses. They generally displayed a low resting level of spike activity in the absence of sensory stimulation, despite a large background of spontaneous synaptic activity, and showed no intrinsic bursting behavior. Presentation of an airborne odor, but not air alone, to an antenna evoked spatially coherent field potential oscillations in the ipsilateral mushroom body, with a frequency of approximately 20 Hz. The frequency of these oscillations was independent of the nature of the odorant. Short bouts of oscillations sometimes occurred spontaneously, that is, in the absence of odorant stimulation. Autocorrelograms of the local field potentials in the absence of olfactory stimulation revealed small peaks at +/- 50 msec, suggesting an intrinsic tendency of the

  17. Locust bean gum as an alternative polymeric coating for embryonic stem cell culture.

    PubMed

    Perestrelo, Ana Rubina; Grenha, Ana; Rosa da Costa, Ana M; Belo, José António

    2014-07-01

    Pluripotent embryonic stem cells (ESCs) have self-renewal capacity and the potential to differentiate into any cellular type depending on specific cues (pluripotency) and, therefore, have become a vibrant research area in the biomedical field. ESCs are usually cultured in gelatin or on top of a monolayer of feeder cells such as mitotically inactivated mouse embryonic fibroblasts (MEFsi). The latter is the gold standard support to maintain the ESCs in the pluripotent state. Examples of versatile, non-animal derived and inexpensive materials that are able to support pluripotent ESCs are limited. Therefore, our aim was to find a biomaterial able to support ESC growth in a pluripotent state avoiding laborious and time consuming parallel culture of MEFsi and as simple to handle as gelatin. Many of the new biomaterials used to develop stem cell microenvironments are using natural polymers adsorbed or covalently attached to the surface to improve the biocompatibility of synthetic polymers. Locust beam gum (LBG) is a natural, edible polymer, which has a wide range of potential applications in different fields, such as food and pharmaceutical industry, due to its biocompatibility, adhesiveness and thickening properties. The present work brings a natural system based on the use of LBG as a coating for ESC culture. Undifferentiated mouse ESCs were cultured on commercially available LBG to evaluate its potential in maintaining pluripotent ESCs. In terms of morphology, ESC colonies in LBG presented the regular dome shape with bright borders, similar to the colonies obtained in co-cultures with MEFsi and characteristic of pluripotent ESC colonies. In short-term cultures, ESC proliferation in LBG coating was similar to ESC cultured in gelatin and the cells maintained their viability. The activity of alkaline phosphatase and Nanog, Sox2 and Oct4 expression of mouse ESCs cultured in LBG were comparable or in some cases higher than in ESCs cultured in gelatin. An in vitro

  18. Canopy transpiration of two black locust (Robinia pseudoacacia) plantations with different ages in semi-arid Loess Plateau, China

    NASA Astrophysics Data System (ADS)

    Jiao, L.

    2015-12-01

    Black locust (Robinia pseudoacacia) was widely planted to control soil erosion and restore degraded ecosystem in Loess Plateau. The water use of the plantations was concerned due to its potential effects on hydrological cycle and regional water resource. Although some studies estimated canopy transpiration (Ec) of the mature black locust plantation, variation in Ec in plantations with different ages was not clear. In this study, we selected two plantations with different ages (12 years and 27 years, denoted as young stand and mature stand, respectively) in similar topographical conditions in Yangjuangou catchment in the central of Loess Plateau. Sap flux density (Fd) and tree biometrics were measured in each stand during the growing season in 2014. Soil water content (SWC) in each plot and meteorological variables in the catchment were simultaneously monitored. Tree transpiration (Et) was derived from Fd and tree sapwood area (As). Canopy transpiration (Ec) was estimated by a product of mean stand sap flux density (Js) and stand total sapwood area (AST). The mean Fd of mature trees was 2-fold larger than that of young trees.However, tree-to-tree variation in Fd among sampled trees within mature stand was evident compared to that within young stand. Mean Et in mature stand was higher than that in young stand. Ec in mature stand was significant higher than that in young stand,with cumulative value of 54 mm and 27 mm respectively. This is attributed to higher Js in mature stand although AST in young is slightly higher than that in mature stand. The patterns of daily Ec during the growing season were similar in both stands during the study period. A exponential saturation model can explain the responses of Ec to vapor deficit pressure (VPD) and solar radiation (Rs) in both stands.The relationship between Ec and SWC was not detected. Our finding suggested that stand age should be taken into consideration when estimated vegetation water use in this region. Further

  19. 16 Extraordinary African Americans.

    ERIC Educational Resources Information Center

    Lobb, Nancy

    This collection for children tells the stories of 16 African Americans who helped make America what it is today. African Americans can take pride in the heritage of these contributors to society. Biographies are given for the following: (1) Sojourner Truth, preacher and abolitionist; (2) Frederick Douglass, abolitionist; (3) Harriet Tubman, leader…

  20. African Studies Computer Resources.

    ERIC Educational Resources Information Center

    Kuntz, Patricia S.

    African studies computer resources that are readily available in the United States with linkages to Africa are described, highlighting those most directly corresponding to African content. Africanists can use the following four fundamental computer systems: (1) Internet/Bitnet; (2) Fidonet; (3) Usenet; and (4) dial-up bulletin board services. The…

  1. African Literature as Celebration.

    ERIC Educational Resources Information Center

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and dignity. (AF)

  2. Educating African American Males

    ERIC Educational Resources Information Center

    Bell, Edward E.

    2010-01-01

    Background: Schools across America spend money, invest in programs, and sponsor workshops, offer teacher incentives, raise accountability standards, and even evoke the name of Obama in efforts to raise the academic achievement of African American males. Incarceration and college retention rates point to a dismal plight for many African American…

  3. Africans Away from Home.

    ERIC Educational Resources Information Center

    Clarke, John Henrik

    Africans who were brought across the Atlantic as slaves never fully adjusted to slavery or accepted its inevitability. Resistance began on board the slave ships, where many jumped overboard or committed suicide. African slaves in South America led the first revolts against tyranny in the New World. The first slave revolt in the Caribbean occurred…

  4. Keeping African Masks Real

    ERIC Educational Resources Information Center

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  5. Diabetes in African Americans

    PubMed Central

    Marshall, M

    2005-01-01

    African Americans have a high risk for type 2 diabetes. Genetic traits, the prevalence of obesity, and insulin resistance all contribute to the risk of diabetes in the African American community. African Americans have a high rate of diabetic complications, because of poor glycaemic control and racial disparities in health care in the USA. African Americans with diabetes may have an atypical presentation that simulates type 1 diabetes, but then their subsequent clinical course is typical of type 2 diabetes. Culturally sensitive strategies, structured disease management protocols, and the assistance of nurses, diabetic educators, and other health care professionals are effective in improving the outcome of diabetes in the African American community. PMID:16344294

  6. Wetland suitability and connectivity for trans-Saharan migratory waterbirds.

    PubMed

    Merken, Ronny; Deboelpaep, Evelien; Teunen, Joachim; Saura, Santiago; Koedam, Nico

    2015-01-01

    To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area) we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica). We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks' overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90-7.36%) and an overall decrease of the network's connectivity (0.65-6.82%). In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland complexes could

  7. Key Features of Intertidal Food Webs That Support Migratory Shorebirds

    PubMed Central

    Saint-Béat, Blanche; Dupuy, Christine; Bocher, Pierrick; Chalumeau, Julien; De Crignis, Margot; Fontaine, Camille; Guizien, Katell; Lavaud, Johann; Lefebvre, Sébastien; Montanié, Hélène; Mouget, Jean-Luc; Orvain, Francis; Pascal, Pierre-Yves; Quaintenne, Gwenaël; Radenac, Gilles; Richard, Pierre; Robin, Frédéric; Vézina, Alain F.; Niquil, Nathalie

    2013-01-01

    The migratory shorebirds of the East Atlantic flyway land in huge numbers during a migratory stopover or wintering on the French Atlantic coast. The Brouage bare mudflat (Marennes-Oléron Bay, NE Atlantic) is one of the major stopover sites in France. The particular structure and function of a food web affects the efficiency of carbon transfer. The structure and functioning of the Brouage food web is crucial for the conservation of species landing within this area because it provides sufficient food, which allows shorebirds to reach the north of Europe where they nest. The aim of this study was to describe and understand which food web characteristics support nutritional needs of birds. Two food-web models were constructed, based on in situ measurements that were made in February 2008 (the presence of birds) and July 2008 (absence of birds). To complete the models, allometric relationships and additional data from the literature were used. The missing flow values of the food web models were estimated by Monte Carlo Markov Chain – Linear Inverse Modelling. The flow solutions obtained were used to calculate the ecological network analysis indices, which estimate the emergent properties of the functioning of a food-web. The total activities of the Brouage ecosystem in February and July are significantly different. The specialisation of the trophic links within the ecosystem does not appear to differ between the two models. In spite of a large export of carbon from the primary producer and detritus in winter, the higher recycling leads to a similar retention of carbon for the two seasons. It can be concluded that in February, the higher activity of the ecosystem coupled with a higher cycling and a mean internal organization, ensure the sufficient feeding of the migratory shorebirds. PMID:24204666

  8. Wetland Suitability and Connectivity for Trans-Saharan Migratory Waterbirds

    PubMed Central

    Teunen, Joachim; Saura, Santiago; Koedam, Nico

    2015-01-01

    To complete their life cycle waterbirds rely on patchily distributed and often ephemeral wetlands along their migration route in a vast unsuitable matrix. However, further loss and degradation of remaining wetland habitats might lead to a configuration and size of stopovers that is no longer sufficient to ensure long-term survival of waterbird populations. By identifying optimal conservation targets to maintain overall habitat availability en route, we can accommodate an as yet absent functional connectivity component in larger management frameworks for migratory waterbirds, such as the Ramsar Convention and the EU Natura 2000 Network. Using a graph-based habitat availability metric (Equivalent Connected Area) we determine the functional connectivity of wetland networks for seven migratory waterbirds with divergent habitat requirements. Analyses are performed at two spatial extents both spanning the Mediterranean Sea and centered around Greece (Balkan-Cyrenaica and Greece-Cyrenaica). We create species-specific suitable habitat maps and account for human disturbance by species-specific disturbance buffers, based on expert estimates of Flight Initiation Distances. At both spatial extents we quantitatively determine the habitat networks’ overall functional connectivity and identify wetland sites that are crucial for maintaining a well-connected network. We show that the wetland networks for both spatial extents are relatively well connected and identify several wetland sites in Greece and Libya as important for maintaining connectivity. The application of disturbance buffers results in wetland site-specific reduction of suitable habitat area (0.90–7.36%) and an overall decrease of the network’s connectivity (0.65–6.82%). In addition, we show that the habitat networks of a limited set of species can be combined into a single network which accounts for their autoecological requirements. We conclude that targeted management in few but specific wetland complexes

  9. Atlantic Leatherback Migratory Paths and Temporary Residence Areas

    PubMed Central

    López-Mendilaharsu, Milagros; Miller, Philip; Domingo, Andrés; Evans, Daniel; Kelle, Laurent; Plot, Virginie; Prosdocimi, Laura; Verhage, Sebastian; Gaspar, Philippe; Georges, Jean-Yves

    2010-01-01

    Background Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns. Methodology/Principal Findings Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings. Conclusions/Significance Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly

  10. African bees to control African elephants

    NASA Astrophysics Data System (ADS)

    Vollrath, Fritz; Douglas-Hamilton, Iain

    2002-11-01

    Numbers of elephants have declined in Africa and Asia over the past 30 years while numbers of humans have increased, both substantially. Friction between these two keystone species is reaching levels which are worryingly high from an ecological as well as a political viewpoint. Ways and means must be found to keep the two apart, at least in areas sensitive to each species' survival. The aggressive African bee might be one such method. Here we demonstrate that African bees deter elephants from damaging the vegetation and trees which house their hives. We argue that bees can be employed profitably to protect not only selected trees, but also selected areas, from elephant damage.

  11. Endoscopic Management of Free Lying Migratory Orthopedic Screw in Bladder.

    PubMed

    P, Puvai Murugan; M, Ramalingam

    2016-09-01

    75-year old gentleman presented with acute urinary retention. He had met with road traffic accident 15 years back and sustained pelvic fracture and bladder rupture, underwent bladder repair and open reduction and internal fixation of pubic symphsis. Imaging studies showed the free lying encrusted orthopedic screw in the bladder, which was removed per urethra using nephroscope. Migratory foreign bodies in the urinary bladder are rare. However there is a possibility of longstanding foreign bodies in adjacent structures to erode and perforate into the bladder. Inside the bladder these foreign bodies act as nidus for stone formation. PMID:27500087

  12. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... have a valid permit issued under 50 CFR 21.27 for scientific research or education, and consistent with... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA...

  13. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... have a valid permit issued under 50 CFR 21.27 for scientific research or education, and consistent with... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA...

  14. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... have a valid permit issued under 50 CFR 21.27 for scientific research or education, and consistent with... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA...

  15. 78 FR 907 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ... Act (Magnuson-Stevens Act) by regulations at 50 CFR part 622. Amendment 18 to the FMP (76 FR 82058... reduces the commercial trip limit of Atlantic migratory group Spanish mackerel in or from the exclusive... coastal migratory pelagic fish (king mackerel, Spanish mackerel, and cobia) is managed under the...

  16. 76 FR 60444 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... accountability measures (AMs) for king mackerel, Spanish mackerel, and cobia. In addition, Amendment 18 proposes... allowable biological catch (ABC). Currently two migratory groups of king mackerel and Spanish mackerel are... for cobia; and establish ACLs, ACTs, and AMs for each migratory group of king mackerel,...

  17. 77 FR 4272 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-27

    ... 3.87 million lb (1.76 million kg) for the Atlantic migratory group of Spanish mackerel (65 FR 41015... reduces the commercial trip limit of Atlantic migratory group Spanish mackerel in or from the exclusive... mackerel, Spanish mackerel, cero, cobia, little tunny, dolphin, and, in the Gulf of Mexico only,...

  18. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... have a valid permit issued under 50 CFR 21.27 for scientific research or education, and consistent with... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA...

  19. 75 FR 56555 - Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-16

    ... completed an EA on take of migrant peregrine falcons in 2008 (73 FR 74508; December 8, 2008). Our preferred... Fish and Wildlife Service Migratory Birds; Take of Migrant Peregrine Falcons for Use in Falconry AGENCY... FURTHER INFORMATION CONTACT: Dr. George Allen, Division of Migratory Bird Management, U.S. Fish...

  20. 50 CFR 92.6 - Use and possession of migratory birds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... have a valid permit issued under 50 CFR 21.27 for scientific research or education, and consistent with... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Use and possession of migratory birds. 92... INTERIOR (CONTINUED) MISCELLANEOUS PROVISIONS MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA...