Gu, Ding; Yang, Da-Rong
The fig tree, Ficus curtipes, hosts an obligate pollinating wasp, an undescribed Eupristina sp., but can also be pollinated by two inquiline (living in the burrow, nest, gall, or other habitation of another animal) wasps, Diaziella yangi and an undescribed Lipothymus sp. The two inquilines are unable to independently induce galls and depend on the galls induced by the obligate pollinator for reproduction and, therefore, normally enter receptive F. curtipes figs colonised by the obligate pollinators. However, sometimes the inquilines also enter figs that are not colonised by the pollinators, despite consequent reproductive failure. It is still unknown which signal(s) the inquilines use in entering the colonised and non-colonised figs. We conducted behavioural experiments to investigate several possible signals utilised by the inquilines in entering their host receptive figs. Our investigation showed that both inquiline species enter the receptive F. curtipes figs in response to the body odours of the obligate wasps and one of the main compounds emitted by the figs, 6-methyl-5-hepten-2-one. The compound was not found in the pollinator body odours, suggesting that the two inquiline wasps can utilise two signals to enter their host figs, which is significant for the evolution of the fig-fig wasp system. These inquilines could evolve to become mutualists of the figs if they evolve the ability to independently gall fig flowers; there is, however, another possibility that a monoecious Ficus species hosting such inquilines may evolve into a dioecious one if these inquilines cannot evolve the above-mentioned ability. Additionally, this finding provides evidence for the evolution of chemical communication between plants and insects. Copyright © 2013 Elsevier Ltd. All rights reserved.
John C. Moser
Nymphs and females of the roach inquiline, Attaphila fungicola W. M. Wheeler, respond to odor-trail substances of Atta texana (Buckley) and Trachymyrmex septentrionalis (McCook).The ants are more sensitive than roaches to the pheromone.
DeSouza, Og; Araújo, Ana Paula Albano; Florencio, Daniela Faria; Rosa, Cassiano Sousa; Marins, Alessandra; Costa, Diogo Andrade; Rodrigues, Vinicius Barros; Cristaldo, Paulo Fellipe
Structural and functional traits of organisms are known to be related to the size of individuals and to the size of their colonies when they belong to one. Among such traits, propensity to inquilinism in termites is known to relate positively to colony size. Larger termitaria hold larger diversity of facultative inquilines than smaller nests, whereas obligate inquilines seem unable to settle in nests smaller than a threshold volume. Respective underlying mechanisms, however, remain hypothetical. Here we test one of such hypotheses, namely, that nest defence correlates negatively to nest volume in Constrictotermes cyphergaster termites (Termitidae: Nasutitermitinae). As a surrogate to defence, we used ‘patrolling rate’, i.e., the number of termite individuals attending per unit time an experimentally damaged spot on the outer wall of their termitaria. We found that patrolling rate decayed allometrically with increasing nest size. Conspicuously higher patrolling rates occurred in smaller nests, while conspicuously lower rates occurred in larger nests presenting volumes in the vicinity of the threshold value for the establishment of inquilinism. This could be proven adaptive for the host and guest. At younger nest age, host colonies are smaller and presumably more vulnerable and unstable. Enhanced defence rates may, hence, prevent eventual risks to hosts from inquilinism at the same time that it prevents inquilines to settle in a still unstable nest. Conversely, when colonies grow and maturate enough to stand threats, they would invest in priorities other than active defence, opening an opportunity for inquilines to settle in nests which are more suitable or less risky. Under this two-fold process, cohabitation between host and inquiline could readily stabilize. PMID:26808197
Cristaldo, Paulo Fellipe; Desouza, Og; Krasulová, Jana; Jirošová, Anna; Kutalová, Kateřina; Lima, Eraldo Rodrigues; Sobotník, Jan; Sillam-Dussès, David
Termite nests are often secondarily inhabited by other termite species ( = inquilines) that cohabit with the host. To understand this association, we studied the trail-following behaviour in two Neotropical species, Constrictotermes cyphergaster (Termitidae: Nasutitermitinae) and its obligatory inquiline, Inquilinitermes microcerus (Termitidae: Termitinae). Using behavioural experiments and chemical analyses, we determined that the trail-following pheromone of C. cyphergaster is made of neocembrene and (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. Although no specific compound was identified in I. microcerus, workers were able to follow the above compounds in behavioural bioassays. Interestingly, in choice tests, C. cyphergaster prefers conspecific over heterospecific trails while I. microcerus shows the converse behaviour. In no-choice tests with whole body extracts, C. cyphergaster showed no preference for, while I. microcerus clearly avoided heterospecific trails. This seems to agree with the hypothesis that trail-following pheromones may shape the cohabitation of C. cyphergaster and I. microcerus and reinforce the idea that their cohabitation is based on conflict-avoiding strategies.
Cristaldo, Paulo Fellipe; DeSouza, Og; Krasulová, Jana; Jirošová, Anna; Kutalová, Kateřina; Lima, Eraldo Rodrigues; Šobotník, Jan; Sillam-Dussès, David
Termite nests are often secondarily inhabited by other termite species ( = inquilines) that cohabit with the host. To understand this association, we studied the trail-following behaviour in two Neotropical species, Constrictotermes cyphergaster (Termitidae: Nasutitermitinae) and its obligatory inquiline, Inquilinitermes microcerus (Termitidae: Termitinae). Using behavioural experiments and chemical analyses, we determined that the trail-following pheromone of C. cyphergaster is made of neocembrene and (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol. Although no specific compound was identified in I. microcerus, workers were able to follow the above compounds in behavioural bioassays. Interestingly, in choice tests, C. cyphergaster prefers conspecific over heterospecific trails while I. microcerus shows the converse behaviour. In no-choice tests with whole body extracts, C. cyphergaster showed no preference for, while I. microcerus clearly avoided heterospecific trails. This seems to agree with the hypothesis that trail-following pheromones may shape the cohabitation of C. cyphergaster and I. microcerus and reinforce the idea that their cohabitation is based on conflict-avoiding strategies. PMID:24465533
Acs, Zoltán; Challis, Richard J; Bihari, Péter; Blaxter, Mark; Hayward, Alexander; Melika, George; Csóka, György; Pénzes, Zsolt; Pujade-Villar, Juli; Nieves-Aldrey, José-Luis; Schönrogge, Karsten; Stone, Graham N
We examine phylogenetic relationships within the Synergus complex of herbivorous inquiline gallwasps (Hymenoptera; Cynipidae; Synergini) associated with cynipid host galls on oak, a biologically diverse group whose genus-level morphological taxonomy has long been considered stable but whose species level taxonomy is problematic. We incorporate data for over 70% of recognised Western Palaearctic species in five morphology-based genera (Ceroptres, Saphonecrus, Synergus, Synophrus, Ufo), comprising sequence for two mitochondrial loci (coxI, cytb) and one nuclear locus (28S D2). In particular, we assess the evidence for monophyly of two long-established, morphology-defined sections within the genus Synergus that differ in a range of biological traits. To aid analyses of ecological interactions within oak cynipid communities, we also consider the utility of cytochrome oxidase I (coxI) DNA barcodes in the oak inquilines. In this assessment, we do not assume that species are delineated at a single threshold value of sequence divergence for a single gene, but examine concordance in the composition of molecular operational Taxonomic units (MOTUs) across a range of sequence divergences in each gene and across genes. We also assess the impact of sampling effort on MOTU stability. Phylogenetic reconstructions for all three loci support monophyly for Synergus and Synophrus, but reject monophyly for Saphonecrus and for the two sections within Synergus. The suites of traits associated with the two sections of the genus Synergus are thus homoplasious. All three loci also reject monophyly for three Synergus species (S. hayneanus, S. pallipes, S. umbraculus). Sequences for each locus identify robust MOTUs that are largely concordant across loci for a range of cut-off values. Though many MOTU's correspond to recognised Linnean species, there is significant, multigene disagreement between groupings supported by morphology and sequence data, with both allocation of different
terHorst, Casey P
Ecologists have long recognized the importance of indirect ecological effects on species abundances, coexistence, and diversity. However, the evolutionary consequences of indirect interactions are rarely considered. Here I conduct selection experiments and examine the evolutionary response of Colpoda sp., a ciliated protozoan, to other members of the inquiline community of purple pitcher plants (Sarracenia purpurea). I measured the evolution of six traits in response to (1) predation by mosquito larvae, (2) competition from other ciliated protozoans, and (3) simultaneous predation and competition. The latter treatment incorporated both direct effects and indirect effects due to interactions between predators and competitors. Population growth rate and cell size evolved in response to direct effects of predators and competitors. However, trait values in the multispecies treatment were similar to those in the monoculture treatment, indicating that direct effects were offset by strong indirect effects on the evolution of traits. For most of the traits measured, indirect effects were opposed to, and often stronger than, direct effects. These indirect effects occurred as a result of behavioral changes of the predator in the presence of competitors and as a result of reduced densities of competitors in the presence of predators. Incorporating indirect effects provides a more realistic description of how species evolve in complex natural communities.
Kneitel, Jamie M
Trade-offs among species' ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species' ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species' traits in the context of coexistence at different scales
Schwéger, Szabina; Melika, George; Tang, Chang-Ti; Yang, Man-Miao; Stone, Graham N; Nicholls, James A; Sinclair, Frazer; Hearn, Jack; Bozsó, Miklós; Pénzes, Zsolt
Fifteen new species of cynipid inquilines, Saphonecrus chinensis Tang & Schwéger, S. gilvus Melika & Schwéger, S. globosus Schwéger & Tang, S. leleyi Melika & Schwéger, S. lithocarpii Schwéger & Melika, S. longinuxi Schwéger & Melika, S. morii Schwéger & Tang, S. nantoui Tang, Schwéger & Melika, S. nichollsi Schwéger & Melika, S. pachylomai Schwéger, Tang & Melika, S. robustus Schwéger & Melika, S. saliciniai Melika, Tang & Schwéger, S. shanzhukui Melika & Tang, S. symbioticus Melika & Schwéger, and S. taitungi Schwéger, Tang & Melika, from the Eastern Palaearctic are described. Descriptions, diagnoses, biology, and host associations for the new species, and a key to Palaearctic Saphonecrus species are given. All new taxa form distinct units as demonstrated by the molecular phylogenetic analyses of Palaearctic Saphonecrus species. The status of some earlier described Saphonecrus species is discussed also. The Synergini genus Lithonecrus Nieves-Aldrey & Butterill, 2014 is synonymized with Lithosaphonecrus Tang, Melika & Bozsó, 2013. Three Saphonecrus species are transferred to Synergus: Synergus brevis (Weld) comb. nova, Synergus hupingshanensis (Liu, Yang & Zhu) comb. nova, and Synergus yukawai (Wachi, Ide & Abe) comb. nova. Synophrus vietnamensis Abe, Ide, Konishi & Ueno is transferred to Lithosaphonecrus: Lithosaphonecrus vietnamensis Abe, Ide, Konishi & Ueno), comb. nova. The current number of valid Saphonecrus species worldwide is 36.
Insects found in birds' nests from Argentina: Coryphistera alaudina Burmeister, 1860 (Aves: Furnariidae), their inquiline birds and mammals, new hosts for Psammolestes coreodes Bergroth, 1911 and Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae: Triatominae).
Turienzo, Paola; Di Iorio, Osvaldo
The insect fauna in nests of Coryphistera alaudina Burmeister, 1860 (Aves: Furnariidae) were studied in the provinces of Santiago del Estero, Chaco, Córdoba, and La Pampa in Argentina. A total of 7364 insect specimens comprising 77 taxa in a total of 29 families and 7 orders was found in their nests: 40 identified to species, 23 identified to genus, and 14 identified to family. Coryphistera alaudina and some of their vertebrate inquilines are new host records for the triatomine bugs Psammolestes coreodes Bergroth, 1911 and/or Triatoma platensis Neiva, 1913 (Hemiptera: Reduviidae). The insects in the nests of C. alaudina are separated by functional guilds, and their permanence time inside the nests are presented in a new manner and discussed.
Miller, Thomas E; terHorst, Casey P
Succession is a foundation concept in ecology that describes changes in species composition through time, yet many successional patterns have not been thoroughly investigated. We highlight three hypotheses about succession that are often not clearly stated or tested: (1) individual communities become more stable over time, (2) replicate communities become more similar over time, and (3) diversity peaks at mid-succession. Testing general patterns of succession requires estimates of variation in trajectories within and among replicate communities. We followed replicate aquatic communities found within leaves of purple pitcher plants (Sarracenia purpurea) to test these three hypotheses. We found that stability of individual communities initially decreased, but then increased in older communities. Predation was highest in younger leaves but then declined, while competition was likely strongest in older leaves, as resources declined through time. Higher levels of predation and competition corresponded with periods of higher stability. As predicted, heterogeneity among communities decreased with age, suggesting that communities became more similar over time. Changes in diversity depended on trophic level. The diversity of bacteria slightly declined over time, but the diversity of consumers of bacteria increased linearly and strongly throughout succession. We suggest that studies need to focus on the variety of environmental drivers of succession, which are likely to vary through time and across habitats.
Leppänen, Jenni; Vepsäläinen, Kari; Savolainen, Riitta
Widely distributed Palearctic insects are ideal to study phylogeographic patterns owing to their high potential to survive in many Pleistocene refugia and—after the glaciation—to recolonize vast, continuous areas. Nevertheless, such species have received little phylogeographic attention. Here, we investigated the Pleistocene refugia and subsequent postglacial colonization of the common, abundant, and widely distributed ant Myrmica rubra over most of its Palearctic area, using mitochondrial DNA (mtDNA). The western and eastern populations of M. rubra belonged predominantly to separate haplogroups, which formed a broad secondary contact zone in Central Europe. The distribution of genetic diversity and haplogroups implied that M. rubra survived the last glaciation in multiple refugia located over an extensive area from Iberia in the west to Siberia in the east, and colonized its present areas of distribution along several routes. The matrilineal genetic structure of M. rubra was probably formed during the last glaciation and subsequent postglacial expansion. Additionally, because M. rubra has two queen morphs, the obligately socially parasitic microgyne and its macrogyne host, we tested the suggested speciation of the parasite. Locally, the parasite and host usually belonged to the same haplogroup but differed in haplotype frequencies. This indicates that genetic differentiation between the morphs is a universal pattern and thus incipient, sympatric speciation of the parasite from its host is possible. If speciation is taking place, however, it is not yet visible as lineage sorting of the mtDNA between the morphs. PMID:22393482
Jirošová, Anna; Sillam-Dussès, David; Kyjaková, Pavlína; Kalinová, Blanka; Dolejšová, Klára; Jančařík, Andrej; Majer, Pavel; Cristaldo, Paulo Fellipe; Hanus, Robert
Termite nests often are referred to as the most elaborate constructions of animals. However, some termite species do not build a nest at all and instead found colonies inside the nests of other termites. Since these so-called inquilines do not need to be in direct contact with the host population, the two colonies usually live in separate parts of the nest. Adaptations of both the inquiline and its host are likely to occur to maintain the spatial exclusion and reduce the costs of potential conflicts. Among them, mutual avoidance, based on chemical cues, is expected. We investigated chemical aspects of cohabitation between Constrictotermes cavifrons (Nasutitermitinae) and its obligatory inquiline Inquilinitermes inquilinus (Termitinae). Inquiline soldiers produce in their frontal glands a blend of wax esters, consisting of the C12 alcohols (3Z)-dodec enol, (3Z,6Z)-dodecadienol, and dodecanol, esterified with different fatty acids. The C12 alcohols appear to be cleaved gradually from the wax esters, and they occur in the frontal gland, in soldier headspace, and in the walls of the inquiline part of the nest. Electrophysiological experiments revealed that (3Z)-dodecenol and (3Z,6Z)-dodecadienol are perceived by workers of both species. Bioassays indicated that inquiline soldier heads, as well as the two synthetic compounds, are attractive to conspecific workers and elicit an arresting behavior, while host soldiers and workers avoid these chemicals at biologically relevant amounts. These observations support the hypothesis that chemically mediated spatial separation of the host and the inquiline is an element of a conflict-avoidance strategy in these species.
Lopez-Osorio, Federico; Perrard, Adrien; Pickett, Kurt M.; Carpenter, James M.; Agnarsson, Ingi
Social parasites exploit the brood-care behaviour and social structure of one or more host species. Within the social Hymenoptera there are different types of social parasitism. In its extreme form, species of obligate social parasites, or inquilines, do not have the worker caste and depend entirely on the workers of a host species to raise their reproductive offspring. The strict form of Emery's rule states that social parasites share immediate common ancestry with their hosts. Moreover, this rule has been linked with a sympatric origin of inquilines from their hosts. Here, we conduct phylogenetic analyses of yellowjackets and hornets based on 12 gene fragments and evaluate competing evolutionary scenarios to test Emery's rule. We find that inquilines, as well as facultative social parasites, are not the closest relatives of their hosts. Therefore, Emery's rule in its strict sense is rejected, suggesting that social parasites have not evolved sympatrically from their hosts in yellowjackets and hornets. However, the relaxed version of the rule is supported, as inquilines and their hosts belong to the same Dolichovespula clade. Furthermore, inquilinism has evolved only once in Dolichovespula. PMID:26473041
New family host and records of Acanthocrios furnarii (Cordero & Vogelsang, 1928) (Hemiptera: Cimicidae) from Argentina, and implications in the transmission mechanism of cimicid bugs among birds' nests.
Di Iorio, Osvaldo; Turienzo, Paola; Bragagnolo, Laura; Santillan, Miguel Angel; Grande, Juan Manuel
Acanthocrios furnarii (Cordero & Vogelsang, 1928) [Hemiptera: Cimicidae: Haematosiphoninae] is an ectoparasite on avian hosts from Argentina and Uruguay. It has been mostly found in mud nests of Furnarius rufus (Gmelin, 1788) [Aves: Furnariidae], but its true hosts are some of the inquiline birds that use F. rufus nests. These inquiline hosts belong to the families Emberizidae, Hirundinidae, Icteridae, Passeridae, and Troglodytidae. Outside F. rufus mud nests, A. furnarii has been found in nests of other Furnariidae, Hirundinidae, and Passeridae. The present work adds the first nonpasserine host (Falconidae) of A. furnarii, together with new records in La Pampa, Argentina. The transmission mechanism of A. furnarii, together with all other cimicid bugs from Argentina and adjacent countries, is increased considering this new host; and we also take into account the birds that nidificate in nest boxes, the cavity-nesting birds in trees and earth, and the inquiline birds in stick nests of Furnariidae and Psittacidae.
Adlassnig, Wolfram; Peroutka, Marianne; Lendl, Thomas
Background Carnivorous pitcher plants (CPPs) use cone-shaped leaves to trap animals for nutrient supply but are not able to kill all intruders of their traps. Numerous species, ranging from bacteria to vertrebrates, survive and propagate in the otherwise deadly traps. This paper reviews the literature on phytotelmata of CPPs. Pitcher Fluid as a Habitat The volumes of pitchers range from 0·2 mL to 1·5 L. In Nepenthes and Cephalotus, the fluid is secreted by the trap; the other genera collect rain water. The fluid is usually acidic, rich in O2 and contains digestive enzymes. In some taxa, toxins or detergents are found, or the fluid is extremely viscous. In Heliamphora or Sarracenia, the fluid differs little from pure water. Inquiline Diversity Pitcher inquilines comprise bacteria, protozoa, algae, fungi, rotifers, crustaceans, arachnids, insects and amphibia. The dominant groups are protists and Dipteran larvae. The various species of CPPs host different sets of inquilines. Sarracenia purpurea hosts up to 165 species of inquilines, followed by Nepenthes ampullaria with 59 species, compared with only three species from Brocchinia reducta. Reasons for these differences include size, the life span of the pitcher as well as its fluid. Mutualistic Activities Inquilines closely interact with their host. Some live as parasites, but the vast majority are mutualists. Beneficial activities include secretion of enzymes, feeding on the plant's prey and successive excretion of inorganic nutrients, mechanical break up of the prey, removal of excessive prey and assimilation of atmospheric N2. Conclusions There is strong evidence that CPPs influence their phytotelm. Two strategies can be distinguished: (1) Nepenthes and Cephalotus produce acidic, toxic or digestive fluids and host a limited diversity of inquilines. (2) Genera without efficient enzymes such as Sarracenia or Heliamphora host diverse organisms and depend to a large extent on their symbionts for prey utilization
The Gall Associates of Asphondylia poss. swaedicola Kieffer & Jörgensen (Diptera: Cecidomyiidae) on Suaeda divaricata Moq. (Amaranthaceae) in Semiarid Argentina and Summary of Parasitic Hymenoptera Associated with Suaeda
We report on the Asphondylia poss. swaedicola inducing apical stem galls on Suaeda divaricate Moq. in the Monte region of Argentina. The inquiline gelechiid Gnorimoschema sp. is confirmed as an associate of A. swaedicola galls. The following hymenopteran parasitoids are associated with this system: ...
John C. Moser
A large nest of Atta texana (Buckley) in central Louisiana was partially excavated in August 1960. Twelve dormancy, 5 detritus, and 93 fungus-garden cavities were found. Fungus-garden cavities near the surface outnumbered those at lower depths and contained most of the fungus material and brood. Inquilines were most numerous in detritus cavities....
Gall wasps (Cynipidae) represent the most spectacular radiation of gall-inducing insects. In addition to true gall formers, gall wasps also include phytophagous inquilines, which live inside the galls induced by gall wasps or other insects. Here we present the first comprehensive molecular and total...
Morphological correlates of necromass accumulation in the traps of an Eastern tropical pitcher plant, Nepenthes ampullaria Jack, and observations on the pitcher infauna and its reconstitution following experimental removal.
Cresswell, James E
I studied the trap morphology, necromass accumulation rates and pitcher infauna of an eastern tropical pitcher plant, Nepenthes ampullaria, that grew in `kerangas' heath forest in the Sungei Ingei Conservation Area, Brunei. I surveyed 164 pitchers distributed among 35 plants and extracted the necromass and larval infauna from the pitchers and then resampled the pitcher contents after 14 days. Plants varied significantly in the morphology of their pitchers, in their rate of necromass accumulation per pitcher and in the abundance and composition of the pitcher infaunas. On average, pitchers accumulated 11.5 mg dry weight over 14 days, but larger pitchers accumulated more necromass than smaller ones. Pitcher morphology explained 45% of the variation in necromass accumulation among plants. On average, pitchers initially contained 26.3 individual larval inquilines. Collectively, the larval infauna was composed of nine taxa of dipteran larvae and infrequent anuran tadpoles. These ten taxa were never found together in a single pitcher and the mean species richness per pitcher was 4.0. Of the six taxa that could be assessed, all except Toxorhynchites spp. had a contagious distribution among the pitchers. Pitcher morphology and necromass accumulation explained only 15% of the variation in inquiline abundance among plants. I found little evidence for the existence of density-dependent interactions between inquiline species: a partial correlation analysis detected only one statistically significant pairwise relationship between the abundances of inquiline taxa, which was a positive association. Fourteen days after being emptied, pitchers contained an average of 9.6 inquilines. There was no evidence that the species composition of the infauna recolonising each pitcher was related to that of its pre-removal infauna.
Ronquist, Fredrik; Nieves-Aldrey, José-Luis; Buffington, Matthew L.; Liu, Zhiwei; Liljeblad, Johan; Nylander, Johan A. A.
Gall wasps (Cynipidae) represent the most spectacular radiation of gall-inducing insects. In addition to true gall formers, gall wasps also include phytophagous inquilines, which live inside the galls induced by gall wasps or other insects. Here we present the first comprehensive molecular and total-evidence analyses of higher-level gall wasp relationships. We studied more than 100 taxa representing a rich selection of outgroups and the majority of described cynipid genera outside the diverse oak gall wasps (Cynipini), which were more sparsely sampled. About 5 kb of nucleotide data from one mitochondrial (COI) and four nuclear (28S, LWRh, EF1alpha F1, and EF1alpha F2) markers were analyzed separately and in combination with morphological and life-history data. According to previous morphology-based studies, gall wasps evolved in the Northern Hemisphere and were initially herb gallers. Inquilines originated once from gall inducers that lost the ability to initiate galls. Our results, albeit not conclusive, suggest a different scenario. The first gall wasps were more likely associated with woody host plants, and there must have been multiple origins of gall inducers, inquilines or both. One possibility is that gall inducers arose independently from inquilines in several lineages. Except for these surprising results, our analyses are largely consistent with previous studies. They confirm that gall wasps are conservative in their host-plant preferences, and that herb-galling lineages have radiated repeatedly onto the same set of unrelated host plants. We propose a revised classification of the family into twelve tribes, which are strongly supported as monophyletic across independent datasets. Four are new: Aulacideini, Phanacidini, Diastrophini and Ceroptresini. We present a key to the tribes and discuss their morphological and biological diversity. Until the relationships among the tribes are resolved, the origin and early evolution of gall wasps will remain elusive
Ronquist, Fredrik; Nieves-Aldrey, José-Luis; Buffington, Matthew L; Liu, Zhiwei; Liljeblad, Johan; Nylander, Johan A A
Gall wasps (Cynipidae) represent the most spectacular radiation of gall-inducing insects. In addition to true gall formers, gall wasps also include phytophagous inquilines, which live inside the galls induced by gall wasps or other insects. Here we present the first comprehensive molecular and total-evidence analyses of higher-level gall wasp relationships. We studied more than 100 taxa representing a rich selection of outgroups and the majority of described cynipid genera outside the diverse oak gall wasps (Cynipini), which were more sparsely sampled. About 5 kb of nucleotide data from one mitochondrial (COI) and four nuclear (28S, LWRh, EF1alpha F1, and EF1alpha F2) markers were analyzed separately and in combination with morphological and life-history data. According to previous morphology-based studies, gall wasps evolved in the Northern Hemisphere and were initially herb gallers. Inquilines originated once from gall inducers that lost the ability to initiate galls. Our results, albeit not conclusive, suggest a different scenario. The first gall wasps were more likely associated with woody host plants, and there must have been multiple origins of gall inducers, inquilines or both. One possibility is that gall inducers arose independently from inquilines in several lineages. Except for these surprising results, our analyses are largely consistent with previous studies. They confirm that gall wasps are conservative in their host-plant preferences, and that herb-galling lineages have radiated repeatedly onto the same set of unrelated host plants. We propose a revised classification of the family into twelve tribes, which are strongly supported as monophyletic across independent datasets. Four are new: Aulacideini, Phanacidini, Diastrophini and Ceroptresini. We present a key to the tribes and discuss their morphological and biological diversity. Until the relationships among the tribes are resolved, the origin and early evolution of gall wasps will remain elusive.
Král, David; Hájek, Jiří
Abstract A new species of the genus Cheleion Vårdal & Forshage, 2010, Cheleion jendeki sp. n., from Johor, Malaysia is described, illustrated and compared with the type species of the genus, Cheleion malayanum Vårdal & Forshage, 2010. Photographs of the two species are presented. The adaptation to inquilinous lifestyle of Cheleion is compared with those in other beetle groups and briefly discussed. PMID:26692807
Lenoir, Jean-Christophe; Lachaud, Jean-Paul; Nettel, Alejandro; Fresneau, Dominique; Poteaux, Chantal
Miniaturized queens, microgynes, are regarded as an alternative reproductive strategy sparsely present through the ant world. The described roles of miniaturized queens include alternative short-distance dispersal morphs, an adaptation to polygyny and inquiline parasites. Some of these inquiline parasite microgynes have been described as a separate species from their host. In the poneromorph group, miniaturized queens are only reported in two Mexican populations of two Ectatomminae: Ectatomma tuberculatum, in which small queens represent an inquiline species ( Ectatomma parasiticum) and Ectatomma ruidum. E. ruidum presents apparently facultative polygyny with microgynes. We used mitochondrial DNA markers and newly developed microsatellite loci to investigate the status as well as the role of microgynes in E. ruidum. We confirmed that microgynes and macrogynes are from the same species. This species is almost exclusively monogynous and monoandrous, supernumerary dealate queens of both types being actually daughters of the mother queen. An apparently polygynous nest was more often headed by a macrogyne than a microgyne. We didn't find any inbreeding or isolation by distance in the studied population, indicating that new gynes are inseminated by unrelated males and can establish a new nest far from their natal nest. However, re-adoption of daughter queens seems to be the rule and rate of microgyny appears to be linked to nest density and environmental factors.
Malinga, Geoffrey M; Valtonen, Anu; Nyeko, Philip; Vesterinen, Eero J; Roininen, Heikki
The relative importance of host-plant resources, natural enemies or their interactions in controlling the population of galling insects and their parasitism is poorly known for tropical gallers. In this study, we assessed the impacts of plant quality and density of host trees in regulating the densities of a galler species, the cecidomyiid leaf galler (Cecidomyiini sp. 1EJV) and its parasitoids and inquilines on Neoboutonia macrocalyx trees in Uganda. We manipulated the nutritional quality (or vigour) and the resource concentration with four levels each of fertilization and the group size of host tree. We then recorded the effects of these treatments on the growth rate and total leaf area of host plants, the density of gallers and their mortality by parasitoids and inquilines. Higher levels of fertilization and host density resulted in significantly higher total leaf area than did ambient nutrient levels, and lowest tree densities, respectively. Fertilization also caused significant change in the growth rate of leaf area. Both higher fertilization and host density caused higher density of gallers. Total leaf area was positively associated with galler density, but within galled replicates, the galled leaves were larger than the ungalled leaves. Although highest levels of fertilization and density of host trees caused significant change in the densities of parasitoids, the rate of parasitism did not change. However, tree-density manipulations increased the rate of inquilinism, but on a very low level. Our results demonstrate a trophic cascade in the tropical galler and its parasitoids as a response to bottom-up effects.
Pujade-Villar, Juli; Wang, Yiping; Guo, Rui; Chen, Xuexin
Abstract Palaearctic species of Periclistus Förster has been systematically described, but a new inquiline gall-wasp, Periclistus qinghainensis sp. n., is described from China. This species was obtained from an unknown stem gall induced on Rosa sp. Diagnosis, distribution and biology of the new species are described in this paper. After examining the types of Periclistus idoneus Belizin, 1973 and Periclistus capillatus Belizin, 1968, it is concluded that Periclistus idoneus belongs to genus Aulacidea, and Periclistus capillatus is a valid species of Periclistus. A key to the Palaearctic Periclistus species is also given. PMID:27408577
Nieves-Aldrey, José Luis; San Blas, Germán
The gall wasp genus Eschatocerus (Hymenoptera, Cynipidae, Eschatocerini), a cynipid genus of gall inducers on Prosopis and Acacia species (Fabaceae), endemic to southern South America, is revised. Complete descriptions of the external morphology of the genus and its three known species, illustrated with scanning electron photographs, are given for the first time, and an updated key for the identification of the species is provided. The biology of the species of Eschatocerus and their galls is described. Host plant associations are given, and the terminal larva of Eschatocerus niger is described for the first time. Preliminary notes on the inquiline and parasitoid community associated with the galls of Eschatocerus species are also given.
López-Núñez, Francisco A; Heleno, Ruben H; Ribeiro, Sérgio; Marchante, Hélia; Marchante, Elizabete
Biological invasions are a major threat to biodiversity and as such understanding their impacts is a research priority. Ecological networks provide a valuable tool to explore such impacts at the community level, and can be particularly insightful for planning and monitoring biocontrol programmes, including the potential for their seldom evaluated indirect non-target effects. Acacia longifolia is among the worst invasive species in Portugal, and has been recently targeted for biocontrol by a highly specific gall-wasp. Here we use an ambitious replicated network approach to: (1) identify the mechanisms by which direct and indirect impacts of A. longifolia can cascade from plants to higher trophic levels, including gallers, their parasitoids and inquilines; (2) reveal the structure of the interaction networks between plants, gallers, parasitoids and inquilines before the biocontrol; and (3) explore the potential for indirect interactions among gallers, including those established with the biocontrol agent, via apparent competition. Over a 15-month period, we collected 31,737 galls from native plants and identified all emerging insects, quantifying the interactions between 219 plant-, 49 galler-, 65 parasitoid- and 87 inquiline-species-one of the largest ecological networks to date. No galls were found on any of the 16 alien plant species. Invasion by A. longifolia caused an alarming simplification of plant communities, with cascading effects to higher trophic levels, namely: a decline of overall gall biomass, and on the richness, abundance and biomass of galler insects, their parasitoids, and inquilines. Correspondingly, we detected a significant decline in the richness of interactions between plants and galls. The invasion tended to increase overall interaction evenness by promoting the local extinction of the native plants that sustained more gall species. However, highly idiosyncratic responses hindered the detection of further consistent changes in network
Rasic, Gordana; Maxwell, Sheri A; Keyghobadi, Nusha
As a component of the inquiline community of the purple pitcher plant (Sarracenia purpurea), the pitcher plant midge Metriocneus knabi has been the subject of various ecological studies. However, very little is known about its characteristics beyond the larval stage, in particular the dispersal ability of adults. This study presents new molecular tools developed for testing of evolutionary and ecological questions in natural populations of this species. We describe a set of 12 microsatellite loci specific to M. knabi that are sufficiently polymorphic to provide insight into population genetic structure and dispersal patterns.
Pfliegler, Walter P.; Báthori, Ferenc; Haelewaters, Danny; Tartally, András
Myrmecophilous arthropods and their manifold relations to host ants are interesting from an evolutionary perspective. Rickia wasmannii is an ectoparasitic fungus belonging to the Laboulbeniales order. Here, we show that inquiline mites can become infected by R. wasmannii, which was thought to be restricted to the genus Myrmica (Hymenoptera: Formicidae). This is the first report of R. wasmannii from an alternative host in another subphylum (Chelicerata). We also found immature fruiting bodies on a larva of Microdon myrmicae (Diptera: Syrphidae), which represents the first report of any Rickia species on flies. This fungus is capable of infecting alternative, unrelated host species as they co-occur in the ant nest “microhabitat”. These observations provide direct evidence for ecological specificity in Laboulbeniales. The presence of R. wasmannii on inquilines in Myrmica ant nests suggests that the parasite may have adapted to the ant nest environment and is less dependent on acquiring specific nutrients from the hosts. However, the alternative cannot be excluded; these infections might also represent chance events if the fungus is incapable of fulfilling its life cycle. PMID:27849516
Stone, Graham N; van der Ham, Raymond W J M; Brewer, Jan G
Trace fossils of insect feeding have contributed substantially to our understanding of the evolution of insect-plant interactions. The most complex phenotypes of herbivory are galls, whose diagnostic morphologies often allow the identification of the gall inducer. Although fossil insect-induced galls over 300Myr old are known, most are two-dimensional impressions lacking adequate morphological detail either for the precise identification of the causer or for detection of the communities of specialist parasitoids and inquilines inhabiting modern plant galls. Here, we describe the first evidence for such multitrophic associations in Pleistocene fossil galls from the Eemian interglacial (130000-115000 years ago) of The Netherlands. The exceptionally well-preserved fossils can be attributed to extant species of Andricus gallwasps (Hymenoptera: Cynipidae) galling oaks (Quercus), and provide the first fossil evidence of gall attack by herbivorous inquiline gallwasps. Furthermore, phylogenetic placement of one fossil in a lineage showing obligate host plant alternation implies the presence of a second oak species, Quercus cerris, currently unknown from Eemian fossils in northwestern Europe. This contrasts with the southern European native range of Q. cerris in the current interglacial and suggests that gallwasp invasions following human planting of Q. cerris in northern Europe may represent a return to preglacial distribution limits.
Loope, Kevin J; Lopez-Osorio, Federico; Dvořák, Libor
While eusociality arose in species with single-mating females, multiple mating by queens has evolved repeatedly across the social ants, bees, and wasps. Understanding the benefits and costs of multiple mating of queens is important because polyandry results in reduced relatedness between siblings, reducing kin-selected benefits of helping while also selecting for secondary social traits that reduce intracolony conflict. The leading hypothesis for the benefits of polyandry in social insects emphasizes advantages of a genetically diverse workforce. Workerless social parasite species (inquilines) provide a unique opportunity to test this hypothesis, since they are derived from social ancestors but do not produce workers of their own. Such parasites are thus predicted to evolve single mating because they would experience the costs of multiple mating but not the benefits if such benefits accrue through the production of a genetically diverse group of workers. Here we show that the workerless social parasite Dolichovespula arctica, a derived parasite of wasps, has reverted to obligate single mating from a facultatively polyandrous ancestor, mirroring a similar reversion from obligate polyandry to approximate monandry in a social parasite of fungus-farming ants. This finding and a comparison with two other cases where inquilinism did not induce reversal to monandry support the hypothesis that facultative polyandry can be costly and may be maintained by benefits of a genetically diverse workforce.
Dedeine, Franck; Ahrens, Michael; Calcaterra, Luis; Shoemaker, D Dewayne
One possible mechanism for interspecific transfer of Wolbachia is through the intimate contact between parasites and their hosts. We surveyed 10 species of fly parasitoids (Pseudacteon spp.) and one inquiline social parasite, Solenopsis daguerrei, for the presence and sequence identity (wsp gene) of Wolbachia. Two Wolbachia variants infecting S. daguerrei were identical to known variants infecting the two common ant host species, Solenopsis invicta and Solenopsis richteri, suggesting possible transfers of Wolbachia between this parasite and their hosts have occurred. Our data also revealed an unexpectedly high diversity of Wolbachia variants within S. daguerrei: up to eight variants were found within each individual, which, to our knowledge, is the highest reported number of Wolbachia variants infecting a single individual of any host species.
Dittrich-Schröder, Gudrun; Wingfield, Michael J; Klein, Hildegard; Slippers, Bernard
DNA extraction from minute hymenopterans and their larvae is difficult and challenging because of their small size indicating a low amount of starting material. Hence, 11 DNA extraction methods were compared to determine their efficacy in isolating DNA. Success of each method was scored on a 2% agarose gel after PCR of the cox 1 mitochondrial locus. A silica-membrane-based approach was the most successful, followed by a method using a combination of incubation buffers and a method using magnetic beads. The method using buffers was the most cost- and time effective. Using this method, larvae from Eucalyptus seed capsule galls could be assigned a role (parasitoid, gall former or inquiline) in the gall-inhabiting complex.
Rasic, Gordana; Keyghobadi, Nusha
We investigated the pattern of spatial genetic structure and the extent of gene flow in the pitcher plant flesh fly Fletcherimyia fletcheri, the largest member of the inquiline community of the purple pitcher plant Sarracenia purpurea. Using microsatellite loci, we tested the theoretical predictions of different hypothesized population models (patchy population, metapopulation, or isolated populations) among 11 bogs in Algonquin Provincial Park (Canada). Our results revealed that the pitcher plant flesh fly exhibits a mixture of patchy and metapopulation characteristics. There is significant differentiation among bogs and limited gene flow at larger spatial scales, but local populations do not experience frequent local extinctions/recolonizations. Our findings suggest a strong dispersal ability and stable population sizes in F. fletcheri, providing novel insights into the ecology of this member of a unique ecological microcosm.
Diehl, E; Junqueira, L K; Berti-Filho, E
This paper reports on ant and termite species inhabiting the mounds (murundus) found in three wetland sites in Santo Antonio da Patrulha. Ants and termites were found in 100% of the mounds of two sites and in 20% of those in the third site. Colonies of Camponotus fastigatus were found inhabiting all the mounds, while colonies of Brachymyrmex sp., Linepithema sp., Pheidole sp., and/or Solenopsis sp. were collected in less than 30% of the mounds. In the mounds of the three sites, colonies of Anoplotermes sp. and/or Aparatermes sp. termites were found together with the ant colonies. Another cohabiting termite species, Cortaritermes sp., was found only in the mounds of one site. The results suggest that C. fastigatus is the species building the mounds, with the other species, whether ants or termites, being the inquilines.
Miller, Donald G; Lawson, Sarah P; Rinker, David C; Estby, Heather; Abbot, Patrick
Social and brood parasitisms are nonconsumptive forms of parasitism involving the exploitation of the colonies or nests of a host. Such parasites are often related to their hosts and may evolve in various ecological contexts, causing evolutionary constraints and opportunities for both parasites and their hosts. In extreme cases, patterns of diversification between social parasites and their hosts can be coupled, such that diversity of one is correlated with or even shapes the diversity of the other. Aphids in the genus Tamalia induce galls on North American manzanita (Arctostaphylos) and related shrubs (Arbutoideae) and are parasitized by nongalling social parasites or inquilines in the same genus. We used RNA sequencing to identify and generate new gene sequences for Tamalia and performed maximum-likelihood, Bayesian and phylogeographic analyses to reconstruct the origins and patterns of diversity and host-associated differentiation in the genus. Our results indicate that the Tamalia inquilines are monophyletic and closely related to their gall-forming hosts on Arctostaphylos, supporting a previously proposed scenario for origins of these parasitic aphids. Unexpectedly, population structure and host-plant-associated differentiation were greater in the non-gall-inducing parasites than in their gall-inducing hosts. RNA-seq indicated contrasting patterns of gene expression between host aphids and parasites, and perhaps functional differences in host-plant relationships. Our results suggest a mode of speciation in which host plants drive within-guild diversification in insect hosts and their parasites. Shared host plants may be sufficient to promote the ecological diversification of a network of phytophagous insects and their parasites, as exemplified by Tamalia aphids. © 2015 John Wiley & Sons Ltd.
Aron, S.; Passera, L.; Keller, L.
Social parasitism, one of the most intriguing phenomena in ants, has evolved to various levels, the most extreme form being parasites that have lost the worker caste and rely completely on the host's worker force to raise their brood. A remarkable feature of workerless social parasites is the small size of sexuals. It has been suggested that reduced size evolved as a means to take advantage of the host's caste-determination system, so that parasite larvae develop into sexuals with less food than is required to produce host workers. An important consequence of size reduction is that it might restrict the host workers' ability to discriminate between the brood of the social parasite and their own brood and might protect parasite sexuals from elimination. We found that sexuals of the workerless inquiline ant Plagiolepis xene were significantly smaller than the sexuals of their host Plagiolepis pygmaea, but remarkably similar to the host workers. The size variance of parasite sexuals was much lower than that of their host; this result possibly suggests that there is very stabilizing selection acting on size of the parasite sexuals. Comparison of the primary (egg) and secondary (adult) sex ratios of the parasite and host showed that miniaturization of P. xene sexuals has been accompanied by their ability to develop into sexuals even when the host P. pygmaea actively prevents production of its own sexuals. These results suggest that the inquiline's size and caste threshold have been reduced such that all individuals in a parasite brood will develop into sexuals. We also found that the adult sex ratio of P. xene was heavily female-biased. This bias probably stems from local mate competition that arises from sexuals mating within the nest. There was no significant difference between the proportion of haploid eggs and adult males produced; this observation indicates that a female-biased sex ratio is achieved by queens producing a higher proportion of diploid eggs rather
Carvalho-Fernandes, Sheila P; Ascendino, Sharlene; Maia, Valéria C; Couri, Márcia S
Surveys in the coastal sandy plains (restingas) of Rio de Janeiro have shown a great richness of galls. We investigated the galling insects in two preserved restingas areas of Rio de Janeiro state: Parque Estadual da Costa do Sol and Reserva Particular do Patrimônio Natural Fazenda Caruara. The collections were done each two months, from June 2011 to May 2012. We investigated 38 points during 45 minutes each per collection. The galls were taken to the laboratory for rearing the insects. A total number of 151 insect galls were found in 82 plant species distributed into 34 botanic families. Most of the galls occurred on leaves and the plant families with the highest richness of galls were Myrtaceae and Fabaceae. All the six insect orders with galling species were found in this survey, where Cecidomyiidae (Diptera) was the main galler group. Hymenoptera and Thysanoptera were found as parasitoids and inquilines in 29 galls. The richness of galls in the surveyed areas reveals the importance of restinga for the composition and diversity of gall-inducing insect fauna.
Iorio, Osvaldo Di; Turienzo, Paola
The family Cavognathidae (Coleoptera: Cucujoidea) in Argentina is represented by three species of the genus Taphropiestes Reitter, 1875: T. fusca Reitter, 1875 [Chubut], T. magna Ślipiński & Tomaszewska, 2010 [Río Negro; Chubut], and T. plaumanni Ślipiński & Tomaszewska 2010 [Buenos Aires]. A total of 2565 larvae (multiple instars), 83 pupae, 2028 live adults, and 16 dead adults of T. plaumanni were found in Argentina between 2005 and 2013 in the nests of birds representing the families Columbidae, Emberizidae, Falconidae, Furnariidae, Hirundinidae, Mimidae, Passeridae, Psittacidae, Troglodytidae and Tyrannidae. The adults were most abundant in closed mud nests of Furnarius rufus (Gmelin, 1788) [Furnariidae] and its inquiline birds, but the larvae were most abundant in wood nest boxes. When T. plaumanni was scarcely represented in bird nests from some localities, Alphitobius diaperinus (Panzer, 1797), an exotic darkling beetle [Col.: Tenebrionidae: Tenebrioninae], and one native species, Phobelius crenatus Blanchard, 1842 [Col.: Tenebrionidae: Lagriinae], were most abundant in stick nests of Furnariidae. In contrast, when A. diaperinus and P. crenatus were absent in one locality from the province of Buenos Aires, T. plaumanni was the most abundant beetle. A complete account of data is provided for these collections of T. plaumanni in Argentina. Known distributional data for all Argentinian species of Taphropiestes are plotted on maps with biogeographical provinces indicated.
Lam, Weng Ngai; Chong, Kwek Yan; Anand, Ganesh S; Tan, Hugh Tiang Wah
The fluid-containing traps of Nepenthes carnivorous pitcher plants (Nepenthaceae) are often inhabited by organisms known as inquilines. Dipteran larvae are key components of such communities and are thought to facilitate pitcher nitrogen sequestration by converting prey protein into inorganic nitrogen, although this has never been demonstrated in Nepenthes Pitcher fluids are also inhabited by microbes, although the relationship(s) between these and the plant is still unclear. In this study, we examined the hypothesis of digestive mutualism between N. gracilis pitchers and both dipteran larvae and fluid microbes. Using dipteran larvae, prey and fluid volumes mimicking in situ pitcher conditions, we conducted in vitro experiments and measured changes in available fluid nitrogen in response to dipteran larvae and microbe presence. We showed that the presence of dipteran larvae resulted in significantly higher and faster releases of ammonium and soluble protein into fluids in artificial pitchers, and that the presence of fluid microbes did likewise for ammonium. We showed also that niche segregation occurs between phorid and culicid larvae, with the former fragmenting prey carcasses and the latter suppressing fluid microbe levels. These results clarify the relationships between several key pitcher-dwelling organisms, and show that pitcher communities facilitate nutrient sequestration in their host.
Stiefel, Vernon L; Margolies, David C
In the grasslands of northeastern Kansas, adult populations of Anomoea flavokansiensis, an oligophagous leaf beetle (subfamily Clytrinae), specialize on Illinois bundleflower (Desmanthus illinoensis) even though other reported host species commonly occur and are simultaneously available. We performed choice feeding tests to examine whether A. flavokansiensis adults have a fixed feeding preference for bundleflower. In choice tests, beetles ate similar amounts of bundleflower and honey locust (Gleditsia triacanthos). In addition, we measured fecundity and longevity of adults in no-choice tests to determine if adults were adapted solely to bundleflower. In no-choice tests, fecundity and longevity were no different for adults feeding on bundleflower and honey locust. We next examined the influence of host plant on the attractiveness of beetle eggs to ants. In northeastern Kansas, Crematogaster lineolata ants are attracted to A. flavokansiensis eggs and carry them into their nests where the larvae hatch and apparently reside as inquilines. C. lineolata exhibited a strong preference for eggs from female A. flavokansiensis that fed exclusively on bundleflower compared to eggs from females that fed exclusively on honey locust. Local populations of A. flavokansiensis in northeastern Kansas may specialize on bundleflower to increase the chances of their eggs being transported by C. lineolata ants into their nests. C. lineolata nests may serve as a predator-free and sheltered environment in which A. flavokansiensis eggs undergo embryogenesis.
Satler, Jordan D.; Zellmer, Amanda J.
Understanding if the members of an ecological community have co-diversified is a central concern of evolutionary biology, as co-diversification suggests prolonged association and possible coevolution. By sampling associated species from an ecosystem, researchers can better understand how abiotic and biotic factors influence diversification in a region. In particular, studies of co-distributed species that interact ecologically can allow us to disentangle the effect of how historical processes have helped shape community level structure and interactions. Here we investigate the Sarracenia alata pitcher plant system, an ecological community where many species from disparate taxonomic groups live inside the fluid-filled pitcher leaves. Direct sequencing of the eukaryotes present in the pitcher plant fluid enables us to better understand how a host plant can shape and contribute to the genetic structure of its associated inquilines, and to ask whether genetic variation in the taxa are structured in a similar manner to the host plant. We used 454 amplicon-based metagenomics to demonstrate that the pattern of genetic diversity in many, but not all, of the eukaryotic community is similar to that of S. alata, providing evidence that associated eukaryotes share an evolutionary history with the host pitcher plant. Our work provides further evidence that a host plant can influence the evolution of its associated commensals. PMID:26788436
Hayman, David I; MacKenzie, Kenna E; Reekie, Edward G
The efficacy of pruning methods for managing blueberry stem galls caused by the chalcid wasp, Hemadas nubilipennis (Ashmead), was studied in five commercial lowbush blueberry (Vaccinium angustifolium Aiton) fields in Nova Scotia, Canada, between October 1999 and May 2000. Blueberry fields were mowed in the fall, and burning treatments were subsequently applied either in the fall or the spring. Three treatments were compared: mowing only, mowing plus fall burning, and mowing plus spring burning. Galls collected from the mow plus spring-burn treatment had the least wasp emergence of the three treatments, while the total number of galls was not affected by treatment. Wasp mortality, not gall destruction, is why wasp emergence is reduced in burn treatments. More galls were located and, for the burn treatments, higher wasp emergence was seen from galls found within the leaf litter than those above it. Five co-inhabitants emerged from blueberry stem galls in this study. Three, Eurytoma solenozopheriae (Ashmead), Sycophila vacciniicola (Balduf), and Orymus vacciniicola (Ashmead) are commonly found associates. The other two, Eupelmus vesicularis (Ritzius) and Pteromalus spp., are new records for Nova Scotia. O. vacciniicola is likely an inquiline because it is the largest wasp emerging from galls, and there was a positive relationship between its emergence and that of H. nubilipennis. Larger gall size improved H. nubilipennis emergence from mow and spring-burn galls. After a field has been mowed in the fall, we recommend a spring burn to reduce gall populations and the threat of product contamination.
Pierce, Naomi E.
DNA barcoding and metabarcoding methods have been invaluable in the study of interactions between host organisms and their symbiotic communities. Barcodes can help identify individual symbionts that are difficult to distinguish using morphological characters, and provide a way to classify undescribed species. Entire symbiont communities can be characterized rapidly using barcoding and especially metabarcoding methods, which is often crucial for isolating ecological signal from the substantial variation among individual hosts. Furthermore, barcodes allow the evolutionary histories of symbionts and their hosts to be assessed simultaneously and in reference to one another. Here, we describe three projects illustrating the utility of barcodes for studying symbiotic interactions: first, we consider communities of arthropods found in the ant-occupied domatia of the East African ant-plant Vachellia (Acacia) drepanolobium; second, we examine communities of arthropod and protozoan inquilines in three species of Nepenthes pitcher plant in South East Asia; third, we investigate communities of gut bacteria of South American ants in the genus Cephalotes. Advances in sequencing and computation, and greater database connectivity, will continue to expand the utility of barcoding methods for the study of species interactions, especially if barcoding can be approached flexibly by making use of alternative genetic loci, metagenomes and whole-genome data. This article is part of the themed issue ‘From DNA barcodes to biomes’. PMID:27481780
Satler, Jordan D; Zellmer, Amanda J; Carstens, Bryan C
Understanding if the members of an ecological community have co-diversified is a central concern of evolutionary biology, as co-diversification suggests prolonged association and possible coevolution. By sampling associated species from an ecosystem, researchers can better understand how abiotic and biotic factors influence diversification in a region. In particular, studies of co-distributed species that interact ecologically can allow us to disentangle the effect of how historical processes have helped shape community level structure and interactions. Here we investigate the Sarracenia alata pitcher plant system, an ecological community where many species from disparate taxonomic groups live inside the fluid-filled pitcher leaves. Direct sequencing of the eukaryotes present in the pitcher plant fluid enables us to better understand how a host plant can shape and contribute to the genetic structure of its associated inquilines, and to ask whether genetic variation in the taxa are structured in a similar manner to the host plant. We used 454 amplicon-based metagenomics to demonstrate that the pattern of genetic diversity in many, but not all, of the eukaryotic community is similar to that of S. alata, providing evidence that associated eukaryotes share an evolutionary history with the host pitcher plant. Our work provides further evidence that a host plant can influence the evolution of its associated commensals.
Shoemaker, D DeWayne; Ahrens, Michael E; Ross, Kenneth G
The systematics of South American fire ants (Solenopsis saevissima species-group) has been plagued by difficulties in recognizing species and their relationships on the basis of morphological characters. We surveyed mtDNA sequences from 623 individuals representing 13 described and undescribed species within the species-group and 18 individuals representing other major Solenopsis lineages to generate a phylogeny of the mitochondrial genome. Our analyses support the monophyly of the S. saevissima species-group, consistent with a single Neotropical origin and radiation of this important group of ants, as well as the monophyly of the socially polymorphic species within the group, consistent with a single origin of polygyny (multiple queens per colony) as a derived form of social organization. The mtDNA sequences of the inquiline social parasite S. daguerrei form a clade that appears to be distantly related to sequences from the several host species, consistent with the view that advanced social parasitism did not evolve via sympatric speciation of intraspecific parasites. An important general finding is that species-level polyphyly of the mtDNA appears to be the rule in this group of ants. The existence of multiple divergent mtDNA lineages within several nominal species (including the pest S. invicta) suggests that the pattern of widespread polyphyly often stems from morphological delimitation that overcircumscribes species. However, in two cases the mtDNA polyphyly likely results from recent interspecific hybridization. While resolving species boundaries and relationships is important for understanding general patterns of diversification of South American fire ants, these issues are of added importance because invasive fire ants are emerging as global pests and becoming important model organisms for evolutionary research.
Klompmaker, Adiël A.; Fraaije, René H. B.
Direct animal behavior can be inferred from the fossil record only in exceptional circumstances. The exceptional mode of preservation of ammonoid shells in the Posidonia Shale (Lower Jurassic, lower Toarcian) of Dotternhausen in southern Germany, with only the organic periostracum preserved, provides an excellent opportunity to observe the contents of the ammonoid body chamber because this periostracum is translucent. Here, we report upon three delicate lobsters preserved within a compressed ammonoid specimen of Harpoceras falciferum. We attempt to explain this gregarious behavior. The three lobsters were studied using standard microscopy under low angle light. The lobsters belong to the extinct family of the Eryonidae; further identification was not possible. The organic material of the three small lobsters is preserved more than halfway into the ammonoid body chamber. The lobsters are closely spaced and are positioned with their tails oriented toward each other. The specimens are interpreted to represent corpses rather than molts. The lobsters probably sought shelter in preparation for molting or against predators such as fish that were present in Dotternhausen. Alternatively, the soft tissue of the ammonoid may have been a source of food that attracted the lobsters, or it may have served as a long-term residency for the lobsters (inquilinism). The lobsters represent the oldest known example of gregariousness amongst lobsters and decapods in the fossil record. Gregarious behavior in lobsters, also known for extant lobsters, thus developed earlier in earth's history than previously known. Moreover, this is one of the oldest known examples of decapod crustaceans preserved within cephalopod shells. PMID:22412846
Polidori, Carlo; García, Alberto Jorge; Nieves-Aldrey, José L
The cuticle of certain insect body parts can be hardened by the addition of metals, and because niche separation may require morphological adaptations, inclusion of such metals may be linked to life history traits. Here, we analysed the distribution and enrichment of metals in the mandibles and ovipositors of a large family of gall-inducing wasps (Cynipidae, or Gall-Wasps) (plus one gall-inducing Chalcidoidea), and their associated wasps (gall-parasitoids and gall-inquilines) (Cynipidae, Chalcidoidea and Ichneumonoidea). Both plant types/organs where galls are induced, as well as galls themselves, vary considerably in hardness, thus making this group of wasps an ideal model to test if substrate hardness can predict metal enrichment. Non-galler, parasitic Cynipoidea attacking unconcealed hosts were used as ecological "outgroup". With varying occurrence and concentration, Zn, Mn and Cu were detected in mandibles and ovipositors of the studied species. Zn tends be exclusively concentrated at the distal parts of the organs, while Mn and Cu showed a linear increase from the proximal to the distal parts of the organs. In general, we found that most of species having metal-enriched ovipositors (independently of metal type and concentration) were gall-invaders. Among gall-inducers, metals in the ovipositors were more likely to be found in species inducing galls in woody plants. Overall, a clear positive effect of substrate hardness on metal concentration was detected for all the three metals. Phylogenetic relationships among species, as suggested by the most recent estimates, seemed to have a weak role in explaining metal variation. On the other hand, no relationships were found between substrate hardness or gall-association type and concentration of metals in mandibles. We suggest that ecological pressures related to oviposition were sufficiently strong to drive changes in ovipositor elemental structure in these gall-associated Hymenoptera.
Lecocq, Thomas; Vereecken, Nicolas J.; Michez, Denis; Dellicour, Simon; Lhomme, Patrick; Valterová, Irena; Rasplus, Jean-Yves; Rasmont, Pierre
Populations on islands often exhibit lower levels of genetic variation and ecomorphological divergence compared to their mainland relatives. While phenotypic differentiation in characters, such as size or shape among insular organisms, has been well studied, insular differentiation in quantitative reproductive traits involved in chemical communication has received very little attention to date. Here, we investigated the impact of insularity on two syntopic bumblebee species pairs: one including species that are phylogenetically related (Bombus terrestris and B. lucorum), and the other including species that interact ecologically (B. terrestris and its specific nest inquiline B. vestalis). For each bumblebee species, we characterized the patterns of variation and differentiation of insular (Corsican) vs. mainland (European) populations (i) with four genes (nuclear and mitochondrial, 3781 bp) and (ii) in the chemical composition of male marking secretions (MMS), a key trait for mate attraction in bumblebees, by gas chromatography-mass spectrometry (GC-MS). Our results provide evidence for genetic differentiation in Corsican bumblebees and show that, contrary to theoretical expectations, island populations of bumblebees exhibit levels of genetic variation similar to the mainland populations. Likewise, our comparative chemical analyses of MMS indicate that Corsican populations of bumblebees are significantly differentiated from the mainland yet they hold comparative levels of within-population MMS variability compared to the mainland. Therefore, insularity has led Corsican populations to diverge both genetically and chemically from their mainland relatives, presumably through genetic drift, but without a decrease of genetic diversity in island populations. We hypothesize that MMS divergence in Corsican bumblebees was driven by a persistent lack of gene flow with mainland populations and reinforced by the preference of Corsican females for sympatric (Corsican) MMS. The
Redundant species, cryptic host-associated divergence, and secondary shift in Sennertia mites (Acari: Chaetodactylidae) associated with four large carpenter bees (Hymenoptera: Apidae: Xylocopa) in the Japanese island arc.
Kawazoe, Kazuhide; Kawakita, Atsushi; Kameda, Yuichi; Kato, Makoto
Sennertia mites live as inquilines in the nests of carpenter bees and disperse as deutonymphs on newly emerged adult bees. Because their life cycle is tightly linked to that of the host bees, Sennertia may diverge in response to speciation in the hosts. However, the majority of Sennertia species are associated with several closely related carpenter bees, suggesting that host speciation may not be reflected in mite genetic structure. Here we investigate the extent of host-associated genetic differentiation in two Sennertia mites (S. alfkeni and S. japonica) that share four closely related, strictly allopatric large carpenter bees (Xylocopa). Analysis of the mitochondrial cytochrome oxidase subunit I (COI) gene in Sennertia unexpectedly indicates that the two species represent morphological variants of a single species, and they collectively group into four distinct, allopatric clades that are uniquely associated with a single Xylocopa host. An exception is the mites associated with X. amamensis of the northernmost populations, which have genotypes typical of those associated with neighboring X. appendiculatacircumvolans. Additional analysis using amplified fragment length polymorphism (AFLP) further corroborates the presence of four mite clades but contrary to the COI data, suggests that the mites of the southernmost population of X. appendiculatacircumvolans have genetic profiles typical of those associated with X. amamensis. These results indicate that some mites have undergone secondary host switch after the formation of the four mite lineages and further experienced mitochondrial introgression during period of lineage coexistence. Overall, our results strongly urge reappraisal of deutonymph-based mite taxonomy and illuminate the importance of host-associated divergence during incipient stage of speciation in chaetodactylid mites. Furthermore, the occurrence of host switch and introgression between genetically differentiated mites entails that two host species
Polidori, Carlo; Nieves-Aldrey, José L.
Comparative studies on antennal sensillar equipment in insects are largely lacking, despite their potential to provide insights into both ecological and phylogenetic relationships. Here we present the first comparative study on antennal morphology and sensillar equipment in female Cynipoidea (Hymenoptera), a large and diverse group of wasps, with special reference to the so-called gall-wasps (Cynipidae). A SEM analysis was conducted on 51 species from all extant cynipoid families and all cynipid tribes, and spanning all known life-histories in the superfamily (gall-inducers, gall-inquilines, and non-gall associated parasitoids). The generally filiform, rarely clavate, antennal flagellum of Cynipoidea harbours overall 12 types of sensilla: s. placoidea (SP), two types of s. coeloconica (SCo-A, SCo-B), s. campaniformia (SCa), s. basiconica (SB), five types of s. trichoidea (ST-A, B, C, D, E), large disc sensilla (LDS) and large volcano sensilla (LVS). We found a great variability in sensillar equipment both among and within lineages. However, few traits seem to be unique to specific cynipid tribes. Paraulacini are, for example, distinctive in having apical LVS; Pediaspidini are unique in having ≥3 rows of SP, each including 6–8 sensilla per flagellomere, and up to 7 SCo-A in a single flagellomere; Eschatocerini have by far the largest SCo-A. Overall, our data preliminarily suggest a tendency to decreased numbers of SP rows per flagellomere and increased relative size of SCo-A during cynipoid evolution. Furthermore, SCo-A size seems to be higher in species inducing galls in trees than in those inducing galls in herbs. On the other hand, ST seem to be more abundant on the antennae of herb-gallers than wood-gallers. The antennal morphology and sensillar equipment in Cynipoidea are the complex results of different interacting pressures that need further investigations to be clarified. PMID:25003514
Aranda-Rickert, Adriana; Rothen, Carolina; Diez, Patricia; González, Ana María; Marazzi, Brigitte
The most widespread form of protective mutualisms is represented by plants bearing extrafloral nectaries (EFNs) that attract ants and other arthropods for indirect defence. Another, but less common, form of sugary secretion for indirect defence occurs in galls induced by cynipid wasps. Until now, such galls have been reported only for cynipid wasps that infest oak trees in the northern hemisphere. This study provides the first evidence of galls that exude sugary secretions in the southern hemisphere and asks whether they can be considered as analogues of plants' EFNs. The ecology and anatomy of galls and the chemical composition of the secretion were investigated in north-western Argentina, in natural populations of the host trees Prosopis chilensis and P. flexuosa . To examine whether ants protect the galls from natural enemies, ant exclusion experiments were conducted in the field. The galls produce large amounts of sucrose-rich, nectar-like secretions. No typical nectary and sub-nectary parenchymatic tissues or secretory trichomes can be observed; instead there is a dense vascularization with phloem elements reaching the gall periphery. At least six species of ants, but also vespid wasps, Diptera and Coleoptera, consumed the gall secretions. The ant exclusion experiment showed that when ants tended galls, no differences were found in the rate of successful emergence of gall wasps or in the rate of parasitism and inquiline infestation compared with ant-excluded galls. The gall sugary secretion is not analogous to extrafloral nectar because no nectar-producing structure is associated with it, but is functionally equivalent to arthropod honeydew because it provides indirect defence to the plant parasite. As in other facultative mutualisms mediated by sugary secretions, the gall secretion triggers a complex multispecies interaction, in which the outcome of individual pair-wise interactions depends on the ecological context in which they take place.
The relative importance of resources (bottom-up forces) and natural enemies (top-down forces) for regulating food web dynamics has been debated, and both forces have been found to be critical for determining food web structure. How the relative importance of top-down and bottom-up forces varies between sites with different abiotic conditions is not well understood. Using the pitcher plant inquiline community as a model system, I examine how the relative importance of top-down and bottom-up effects differs between two disparate sites. Resources (ant carcasses) and top predators (mosquito larvae) were manipulated in two identical 4 × 4 factorial press experiments, conducted at two geographically distant sites (Michigan and Florida) within the range of the purple pitcher plant, Sarracenia purpurea, and the aquatic community that resides in its leaves. Overall, top predators reduced the density of prey populations while additional resources bolstered them, and the relative importance of top-down and bottom-up forces varied between sites and for different trophic levels. Specifically, top-down effects on protozoa were stronger in Florida than in Michigan, while the opposite pattern was found for rotifers. These findings experimentally demonstrate that the strength of predator-prey interactions, even those involving the same species, vary across space. While only two sites are compared in this study, I hypothesize that site differences in temperature, which influences metabolic rate, may be responsible for variation in consumer-resource interactions. These findings warrant further investigation into the specific factors that modify the relative importance of top-down and bottom-up effects.
Polidori, Carlo; García, Alberto Jorge; Nieves-Aldrey, José L.
The cuticle of certain insect body parts can be hardened by the addition of metals, and because niche separation may require morphological adaptations, inclusion of such metals may be linked to life history traits. Here, we analysed the distribution and enrichment of metals in the mandibles and ovipositors of a large family of gall-inducing wasps (Cynipidae, or Gall-Wasps) (plus one gall-inducing Chalcidoidea), and their associated wasps (gall-parasitoids and gall-inquilines) (Cynipidae, Chalcidoidea and Ichneumonoidea). Both plant types/organs where galls are induced, as well as galls themselves, vary considerably in hardness, thus making this group of wasps an ideal model to test if substrate hardness can predict metal enrichment. Non-galler, parasitic Cynipoidea attacking unconcealed hosts were used as ecological “outgroup”. With varying occurrence and concentration, Zn, Mn and Cu were detected in mandibles and ovipositors of the studied species. Zn tends be exclusively concentrated at the distal parts of the organs, while Mn and Cu showed a linear increase from the proximal to the distal parts of the organs. In general, we found that most of species having metal-enriched ovipositors (independently of metal type and concentration) were gall-invaders. Among gall-inducers, metals in the ovipositors were more likely to be found in species inducing galls in woody plants. Overall, a clear positive effect of substrate hardness on metal concentration was detected for all the three metals. Phylogenetic relationships among species, as suggested by the most recent estimates, seemed to have a weak role in explaining metal variation. On the other hand, no relationships were found between substrate hardness or gall-association type and concentration of metals in mandibles. We suggest that ecological pressures related to oviposition were sufficiently strong to drive changes in ovipositor elemental structure in these gall-associated Hymenoptera. PMID:23894668
Zander, Axel; Bersier, Louis-Félix; Gray, Sarah M
Climate change research has demonstrated that changing temperatures will have an effect on community-level dynamics by altering species survival rates, shifting species distributions, and ultimately, creating mismatches in community interactions. However, most of this work has focused on increasing temperature, and still little is known about how the variation in temperature extremes will affect community dynamics. We used the model aquatic community held within the leaves of the carnivorous plant, Sarracenia purpurea, to test how food web dynamics will be affected by high temperature variation. We tested the community response of the first (bacterial density), second (protist diversity and composition), and third trophic level (predator mortality), and measured community respiration. We collected early and late successional stage inquiline communities from S. purpurea from two North American and two European sites with similar average July temperature. We then created a common garden experiment in which replicates of these communities underwent either high or normal daily temperature variation, with the average temperature equal among treatments. We found an impact of temperature variation on the first two, but not on the third trophic level. For bacteria in the high-variation treatment, density experienced an initial boost in growth but then decreased quickly through time. For protists in the high-variation treatment, alpha-diversity decreased faster than in the normal-variation treatment, beta-diversity increased only in the European sites, and protist community composition tended to diverge more in the late successional stage. The mortality of the predatory mosquito larvae was unaffected by temperature variation. Community respiration was lower in the high-variation treatment, indicating a lower ecosystem functioning. Our results highlight clear impacts of temperature variation. A more mechanistic understanding of the effects that temperature, and especially
Barden, Phillip; Grimaldi, David A
Across terrestrial ecosystems, modern ants are ubiquitous. As many as 94 out of every 100 individual arthropods in rainforests are ants, and they constitute up to 15% of animal biomass in the Amazon. Moreover, ants are pervasive agents of natural selection as over 10,000 arthropod species are specialized inquilines or myrmecomorphs living among ants or defending themselves through mimicry. Such impact is traditionally explained by sociality: ants are the first major group of ground-dwelling predatory insects to become eusocial, increasing efficiency of tasks and establishing competitive superiority over solitary species. A wealth of specimens from rich deposits of 99 million-year-old Burmese amber resolves ambiguity regarding sociality and diversity in the earliest ants. The stem-group genus Gerontoformica maintained distinct reproductive castes including morphotypes unknown in solitary aculeate (stinging) wasps, providing insight into early behavior. We present rare aggregations of workers, indicating group recruitment as well as an instance of interspecific combat; such aggression is a social feature of modern ants. Two species and an unusual new genus are described, further expanding the remarkable diversity of early ants. Stem-group ants are recovered as a paraphyletic assemblage at the base of modern lineages varying greatly in size, form, and mouthpart structure, interpreted here as an adaptive radiation. Though Cretaceous stem-group ants were eusocial and adaptively diverse, we hypothesize that their extinction resulted from the rise of competitively superior crown-group taxa that today form massive colonies, consistent with Wilson and Hölldobler's concept of "dynastic succession."
Yang, Xiao-Hui; Zhu, Dao-Hong; Liu, Zhiwei; Zhao, Ling; Su, Cheng-Yuan
Wolbachia are maternally inherited endosymbiotic bacteria of arthropods and nematodes. In arthropods, they manipulate the reproduction of their hosts to facilitate their own spread in host populations, causing cytoplasmic incompatibility, parthenogenesis induction, feminization of genetic males and male-killing. In this study, we investigated Wolbachia infection and studied wsp (Wolbachia surface protein) sequences in three wasp species associated with the unisexual galls of A. mukaigawae with the aim of determining the transmission mode and the reason for multiple infections of Wolbachia. Frequency of Wolbachia infected populations for A. mukaigawae, Synergus japonicus (inquiline), and Torymus sp. (parasitoid) was 75%, 100%, and 100%, respectively. Multiple Wolbachia infections were detected in A. mukaigawae and S. japonicus, with 5 and 8 Wolbachia strains, respectively. The two host species shared 5 Wolbachia strains and were infected by identical strains in several locations, indicating horizontal transmission of Wolbachia. The transmission potentially takes place through gall tissues, which the larvae of both wasps feed on. Furthermore, three recombination events of Wolbachia were observed: the strains W8, W2 and W6 apparently have derived from W3 and W5a, W6 and W7, W4 and W9, respectively. W8 and W2 and their respective parental strains were detected in S. japonicus. W6 was detected with only one parent (W4) in S. japonicus; W9 was detected in Torymus sp., suggesting horizontal transmission between hosts and parasitoids. In conclusion, our research supports earlier studies that horizontal transmission of Wolbachia, a symbiont of the Rickettsiales order, may be plant-mediated or take place between hosts and parasitoids. Our research provides novel molecular evidence for multiple recombination events of Wolbachia in gall wasp communities. We suggest that genomic recombination and potential plant-mediated horizontal transmission may be attributable to the high
Voultsiadou, Eleni; Pyrounaki, Maria-Myrto; Chintiroglou, Chariton
The solitary ascidian Microcosmus sabatieri is a common ecosystem engineering species on hard bottom sublittoral communities in the Eastern Mediterranean. Peracarida are common inhabitants of biological substrata, such as algae, sponges and ascidians and have been proven to be very sensitive to changes in environmental conditions. The aim of this study was to present and analyse, for the first time, the structure of the peracarid epifaunal assemblage inhabiting this Mediterranean endemic, edible and commercially exploited species. During sampling in the North Aegean Sea, 41 specimens were collected and examined for their peracarid epifauna. Overall, 38 peracarid species were identified, a high number in comparison to those recorded in the few other relevant studies on ascidian epifauna. The great majority of the species were amphipods. By contrast, in terms of abundance, tanaidaceans was the dominant taxon, with Leptochelia savigni being by far the most dominant species. Tube-dwelling suspension-feeders dominated the peracarid epifauna of this tunicate. The suspension feeding mode of epifaunal peracarids is possibly favoured by the high filtration rate of M. sabatieri which is large sized and has an extensive branchial surface. It is suggested that the tube-dwelling habit of tanaidaceans and some amphipods offering extra protection, may further explain their dominance as elements of the epifauna, in contrast to other inquiline peracarids which prefer to search for shelter inside the canals of sponges or, in a few cases inside the mantle cavity of ascidians. Differences in peracarid abundance among the ascidian specimens were attributed to the reproductive and dispersal habits of the former. Species richness, abundance and diversity of the motile peracarid epifauna was dependent on the biomass of the ascidian, but most strongly on the biomass of the sessile epibiontic organisms, such as algae and sponges which, in some cases, had a higher biomass than the ascidian
Kopelke, Jens-Peter; Nyman, Tommi; Cazelles, Kévin; Gravel, Dominique; Vissault, Steve; Roslin, Tomas
Communities consist of species and their interactions. They can thus be described as networks, with species as nodes and interactions as links. Within such networks, the diversity of nodes and the distribution of links may affect patterns of energy transfer between trophic levels, the dynamics of the system, and the outcome in terms of ecosystem functioning. To date, most descriptions of networks have focused on single or relatively few sites, and have oftentimes been built on poorly resolved nodes and links. Yet, comparisons of local interaction networks reveal variation in space and in time, thus spurring interest in methods and theory for understanding patterns, drivers, and consequences of this variation. Progress in this field relies on access to replicate samples of comparable food webs across large spatiotemporal scales, resolved to species rather than to compound nodes. Due to the massive efforts required, high-quality data sets are still scarce. We created a data set on a single community type sampled across Europe: willow species (Salix), willow-galling sawflies (Hymenoptera: Tenthredinidae: Nematinae: Euurina), and their natural enemies (hymenopteran parasitoids and coleopteran, lepidopteran, dipteran, and hymenopteran inquilines). Each sample was referenced in space and time, and each node resolved with the highest possible resolution, including taxonomic affinity, gall type (for herbivores), and mode of parasitism (for natural enemies). Galler survival and link structure were resolved by dissection and rearing of gall inhabitants. In total, the data set is based on 641 site visits over 29 years, and on 165,424 galls representing 96 herbivore nodes and 52 plant nodes. The dissections and rearings yielded 42,129 natural enemies belonging to 126 species, and revealed 1,173 different links. The spatiotemporal and taxonomic resolution of these data make them amenable to analyses of both ecological and evolutionary processes of network assembly. Thus, this
Caterino, Michael S.; Tishechkin, Alexey K.
Abstract We revise the large Neotropical genus Operclipygus Marseul, in the histerid tribe Exosternini (Histeridae: Histerinae). We synonymize 3 species, move 14 species from other genera, sink the genus Tribalister Horn into Operclipygus, and describe 138 species as new, bringing the total to 177 species of Operclipygus. Keys are provided for the identification of all species, and the majority of the species are illustrated by habitus and male genitalia illustrations. The species are diverse throughout tropical South and Central America, with only a few species extending into the temperate parts of North America. The majority of species can be recognized by the presence of a distinct stria or sulcus along the apical margin of the pygidium, though it is not exclusive to the genus. Natural history details for species of Operclipygus are scant, as most specimens have been collected through the use of passive flight interception traps. Many are probably generally associated with decaying vegetation and leaf litter, where they prey on small arthropods. But a small proportion are known inquilines, with social insects such as ants and termites, and also with some burrowing mammals, such as Ctenomys Blainville. The genus now includes the following species groups and species: Operclipygus sulcistrius group [Operclipygus lucanoides sp. n., Operclipygus schmidti sp. n., Operclipygus simplistrius sp. n., Operclipygus sulcistrius Marseul, 1870], Operclipygus mirabilis group [Operclipygus mirabilis (Wenzel & Dybas, 1941) comb. n., Operclipygus pustulifer sp. n., Operclipygus plaumanni sp. n., Operclipygus sinuatus sp. n., Operclipygus mutuca sp. n., Operclipygus carinistrius (Lewis, 1908) comb. n., Operclipygus parensis sp. n., Operclipygus schlingeri sp. n.], Operclipygus kerga group [Operclipygus kerga (Marseul, 1870), Operclipygus planifrons sp. n., Operclipygus punctistrius sp. n.], Operclipygus conquisitus group [Operclipygus bicolor sp. n., Operclipygus conquisitus (Lewis