Lacey, Michael J.; Bedding, Robin A.
Proto-anhydrobiosis of the nematode, Beddingia siricidicola, was achieved by incubation in polyethylene glycol or various concentrations up to 4 M of glycerol. The associated changes in the levels of glycerol, unbound proline, trehalose, lipids, and glycogen were determined by alkylation strategies, followed by gas chromatography or gas chromatography/mass spectrometry. The level of glycerol reached 8.9% of dry weight, proline 2.4% of dry weight, and trehalose 8.0% of dry weight within B. siricidicola that were incubated in 1.5 M glycerol over 6 d, while glycerol reached 17.9% of dry weight after incubation for the same period in 4 M glycerol. Movement was thereby reduced but the nematodes from 1.5 M glycerol revived after a few minutes upon rehydrating and they were able to avoid osmotic damage by rapidly excreting the glycerol, much of it being expelled within the first hour. The potential for storage and transport of this nematode for the biological control of the pine-killing wasp, Sirex noctilio, was greatly improved when nematode suspensions were maintained in 1.5 M glycerol under refrigeration. PMID:26170473
Tomar, V. V. S.; Somvanshi, Vishal S.; Bajaj, Harish K.
Two different nematodes were isolated from the bark of Albizia lebbeck trees; one from insect infested and another from noninfested, healthy tree. Based on the biological, morphological, and molecular evidences, the nematodes are described as Deladenus albizicus n. sp. and D. processus n. sp. (Nematoda: Hexatylina). Deladenus albizicus n. sp., isolated from insect-infested tree, multiplied on the fungus Nigrospora oryzae. Myceliophagous females of this nematode reproduced by parthenogenesis and spermathecae were indistinct. Infective females, readily produced in the cultures, are dorsally curved. Only one type of males containing small-sized sperms in their genital tracts were produced in the culture. Myceliophagous females: L = 0.75 to 1.71 mm, a = 32.3 to 50.8, b = 9.3 to 11.2, b’ = 5.2 to 7.3, c = 27.2 to 35.6, V = 91.0 to 93.3, c’ = 2.0 to 2.9, stylet = 11 to 12 µm, excretory pore in the region of median pharyngeal bulb, 43 to 47 µm anterior to hemizonid. Deladenus processus n. sp., isolated from bark of healthy A. lebbeck tree, was cultured on Alternaria alternata. Myceliophagous females reproduced by amphimixis and their spermathecae contained rounded sperms. Infective females were never produced, even in old cultures. Myceliophagous females: L = 0.76 to 0.99 mm, a = 34 to 49, b = 13.3 to 17.7, b’ = 3.8 to 5.8, c = 19.6 to 22.8, V = 92.2 to 93.5, c’ = 2.7 to 3.5, stylet = 6 to 7 µm, excretory pore in the proximity of hemizonid, tail conoid, tapering from both sides to a long pointed central process. It is proposed to classify Deladenus species in three groups: durus, siricidicola, and laricis groups based on female and spermatogonia dimorphism, mode of reproduction, and insect parasitism. PMID:25861116
Nasira, K.; Shahina, F.; Firoza, K.
Deladenus cocophilus n. sp. was isolated from infested coconut fruits in Winder, Balochistan, Pakistan. Descriptions are given of the entomophagous (insect-parasitic females) and mycetophagous (fungus-feeding) free-living females, males, and juveniles. The new species D. cocophilus resembles those species in which the excretory pore is situated anterior to the hemizonid, namely, D. apopkaetus Chitambar, 1991; D. leptosoma Gagarin, 2001; D. ipini Massey, 1974; D. laricis (Blinova and Korentchenko, 1986) Ebsarry, 1991; D. (siricidicola) canii Bedding, 1974; D. (s) imperialis Bedding, 1974; D. nevexii Bedding, 1974; D. (wilsoni) proximus Bedding, 1974; D. (s) rudyi Bedding, 1974; D. (s) siricidicola Bedding, 1968; D. (wilsoni) wilsoni Bedding, 1968 and D. minimus Chizhov and Sturhan, 1998. The new species differs from D. ipini in the absence of a post uterine sac vs. present; a = 17 to 30 vs. 35 to 40; stylet = 8 to 10 vs. 11 to 12 μm and vulva-anus = 21 to 28 vs. 35 to 48 μm. From D. apopkaetus it differs in tail length in female 22 to 28 vs. 31 to 43 μm and in the male it is 24 to 32 vs. 30 to 46 μm. It differs from D. leptosoma in the c ratio in females, c = 21 to 37 vs. 16 to 22, presence of 6 lines in lateral field vs. 10 lines and slightly longer spicules 16 to 18 vs. 15 to 16 μm. From D. laricis it differs in a shorter stylet length 8 to 10 vs. 11 to 12 μm; in the c ratio in males 16 to 22 vs. 22 to 35 and hemizonid from anterior end 76 to 90 vs. 90 to 119 μm. It also differs from the following species: D. (siricidicola) canii; D. (s) imperialis; D. nevexii; D. (wilsoni) proximus; D. (s) rudyi; D. (s) siricidicola; D. (wilsoni) wilsoni and D. minimus in having shorter tail length, lower values of a,b,c ratios and a slightly anteriorly located vulva in females. PMID:23833325
Popovic, Vanja; Gu, Jianfeng
Deladenus valveus n. sp., isolated from packaging wood originated from South Korea and intercepted in Ningbo, P.R. China, is described and illustrated. Both mycetophagous and infective forms were recovered and are described. The new species D. valveus n. sp. resembles other Deladenus species in which the excretory pore is situated anterior to the hemizonid: in mycetophagous females, the excretory pore is 59 to 74 μm from the anterior end and 37 to 54 μm anterior to the hemizonid. The new species is characterized by the presence of a distinct valve at the esophago-intestinal junction in mycetophagous females and by a degenerate esophagus in mycetophagous males, both of which characters are reported for the first time in a species of Deladenus. PMID:24987163
Olatinwo, Rabiu; Allison, Jeremy; Meeker, James; Johnson, Wood; Streett, Douglas; Aime, M Catherine; Carlton, Christopher
The woodwasp Sirex noctilio F. (Hymenoptera: Siricidae) has become established in North America. A primary tactic for the management of S. noctilio in the southern hemisphere has been the development of a biological control agent, Deladenus siricidicola Bedding. This nematode has a bicyclic life cycle including a mycetophagous free-living and parasitic cycle. During oviposition, female Sirex woodwasps inject a symbiotic fungus. Because D. siricidicola only develops well on Amylostereum areolatum (Chaillet ex Fries) Boidin (Russulales: Amylostereaceae) and North American woodwasps were thought to all have Amylostereum chailletii (Persoon) Boidin as their fungal symbiont, the risk of unintended impacts from D. siricidicola in North America was considered low. Specific polymerase chain reaction primers were designed to amplify the intergenic spacer region of Amylostereum symbionts in a population of the native woodwasp Sirex nigricornis F. located in central Louisiana (i.e., well outside the known distribution of S. noctilio); identity of the symbiont was confirmed by phylogenetic analyses. Overall, 95 out of 100 fungal isolates obtained from the mycangia of S. nigricornis were identified as Amylostereum species. Contrary to expectations, 60% were identified as A. chailletii (N = 60), while 35% were identified as A. areolatum (N = 35). The remaining 5% of these isolates (N = 5) were identified as Bipolaris papendorfii (Aa) Alcorn, Alternaria alternata (Fr.) Keissl, Penicillium marneffei Segretain, Scytalidium cuboideum (Sacc. & Ellis) Sigler & Kang, and Hyphopichia heimii (Pignal) Kurtzman based on sequencing of the internal transcribed spacer (ITS) region. The five non-Amylostereum isolates were likely contaminants during mycangia-spore extraction process. This study confirms the presence of A. areolatum in a population of the native woodwasp S. nigricornis well outside the known distribution of S. noctilio. PMID:24468555
Yousuf, Fazila; Gurr, Geoff M; Carnegie, Angus J; Bedding, Robin A; Bashford, Richard; Gitau, Catherine W; Nicol, Helen I
The corticoid fungus, Amylostereum areolatum, is deposited in pine trees by the woodwasp, Sirex noctilio, at the time of oviposition. This fungus is essential in S. noctilio larval growth and it is also a food source for Beddingia siricidicola, the nematode used for S. noctilio biological control. In recent years, the historically successful biological control programme has been disrupted in Australia by the bark beetle, Ips grandicollis. This study investigated whether the mechanism of this disruption involves a fungus, Ophiostoma ips, which I. grandicollis introduces into trees. In artificial and wood media, A. areolatum was unable to grow in areas occupied by O. ips. The latter fungus was faster growing, especially at 25 °C rather than 20 °C. Larval galleries of S. noctilio in field-collected samples were strongly associated with wood infested by A. areolatum and absent from areas affected by O. ips. The nematode failed to survive and reproduce on O. ips as it can on A. areolatum. Competitive interactions between O. ips and A. areolatum within the trap trees are demonstrated to be key factors in the negative effect of I. grandicollis on S. noctilio biological control programmes. PMID:24308452
Test of nonhost angiosperm volatiles and verbenone to protect trap trees for Sirex noctilio (Hymenoptera: Siricidae) from attacks by bark beetles (Coleoptera: Scolytidae) in the northeastern United States.
Dodds, Kevin J; Miller, Daniel R
Sirex noctilio F. (Hymenoptera: Siricidae) is an invasive woodwasp, currently established in northeastern North America. In other regions of the world, stressed trap trees are used to monitor populations of S. noctilio and to provide inoculation points for the biological control nematode Deladenus siricidicola Bedding. However, the operational use of trap trees for S. noctilio in North America may be compromised by the large community of native organisms that inhabit stressed and dying pine trees. Common bark beetles such as Ips pini (Say) and Ips grandicollis (Eichhoff) (Coleoptera: Scolytidae) could potentially compete with S. noctilio and associates for resources on trap trees, possibly reducing the efficacy of trap trees as habitats for the woodwasp. In an attempt to develop a technology to mitigate this potential issue, three common semiochemical interruptants--conophthorin, green leaf volatile mix, and verbenone--were tested for effectiveness in reducing arrivals of I. pini and I. grandicollis on trap trees treated with herbicides in northeastern United States. In addition, the effects of these compounds were determined independently with pheromone-baited multiple-funnel traps. None of the interruptants reduced numbers of I. pini or I. grandicollis either arriving on trap trees or caught in pheromone-baited traps. However, verbenone increased catches of I. grandicollis in traps baited with its pheromone, ipsenol. The mix of green leaf volatiles reduced catches of a native ambrosia beetle, Gnathotrichus materiarius (Fitch), whereas verbenone reduced trap catches of an exotic ambrosia beetle, Xylosandrus germanus (Blandford). Catches of X. germanus in traps adjacent to trap trees were enhanced with conophthorin. PMID:21309230
Yaghoubi, Ali; Pourjam, Ebrahim; Pedram, Majid; Siddiqi, Mohammad Rafiq; Atighi, Mohammad Reza
Abursanema iranicum n. gen., n. sp. is described and illustrated based on morphological, morphometric and molecular characters. The new genus is characterized by its smooth outer and annulated inner cuticle, having two incisures in lateral field, lacking stylet knobs, having pyriform terminal bulb with stem-like extension projecting into the intestine and lacking of bursa in male. The new genus belongs to the family Paurodontidae. It most closely resembles the genera Paurodontoides and Paurodontus, but has affinities based on male characters with Gymnotylenchus of the family Neotylenchidae too. From Paurodontoides, it differs by the absence of stylet knobs and having six sectors in the head framework. Compared to Paurodontus, the new genus differs by the absence of stylet knobs, structure of the pharynx and absence of a bursa in male. It differs from Gymnotylenchus mainly by lacking of stylet knobs, presence of a basal pharyngeal bulb with an extension into the intestine and in the structure of the spicules. Molecular phylogenetic studies of the new genus using 706 bp partial sequences of the 28S rDNA D2/D3 segment revealed it forming a clade with two species of Sphaerularia in both Bayesian Inference (BI) and maximum likelihood (ML) analyses with 1.00 Bayesian posterior probability (BPP) and 0.96 bootstrap support values (BS). Using 942 bp partial sequences of 18S ribosomal RNA gene, the new genus formed a clade with a species of Deladenus with 0.86 BPP and 0.62 BS in BI and ML methods, respectively. With both BI and ML methods, this clade forms a larger highly supported clade with two species of Sphaerularia. PMID:24990048