@article{torres-barragan_suazo_buhler_cardoza_2011, title={Studies on the entomopathogenicity and bacterial associates of the nematode Oscheius carolinensis}, volume={59}, ISSN={["1090-2112"]}, DOI={10.1016/j.biocontrol.2011.05.020}, abstractNote={The entomopathogenic potential of Oscheius carolinensis (Nematoda: Rhabditidae), a recently described nematode species, was tested on various developmental stages of five insect species. The nematode penetrated, killed, and reproduced in all of the insect species tested; however, some insect developmental stages proved more susceptible to infection than others. O. carolinensis was consistently associated with four bacterial species, one of which, Serratia marcescens, appears to be carried on the cuticle of the nematodes and through its association provides the worms with entomopathogenic potential. In manual inoculation assays, S. marcescens killed fourth-instar Helicoverpa zea larvae within 24 h at concentrations as low as 330 μg/mL (3.96 × 103 CFU). Another species, Enterococcus mundtii, inflicted levels of mortality of 33.3% only after mechanical wounding (pin-pricking) of H. zea and at much higher concentrations. A third species, Achromobacter xylosoxidans, did not cause mortality even at the highest dose tested (500 mg/mL or 6 × 106 CFU), with or without wounding. The fourth species, Providencia rettgeri, predominant in ground-up surface sterilized nematodes, caused low levels of mortality (25%) when manually applied to pin-picked larvae larvae. Nematodes did not performed well on insect hosts after surface sterilization; nonetheless, it is possible that P. rettgeri in combination with S. marcescens is responsible for the facultative insect colonization ability of O. carolinensis. Based on results from this study it would appear that O. carolinensis association with its bacteria allows the nematode a dual life: style as an entomopathogen when associated with S. macescens, and to an extent with P. rettgeri, and as a free-living entity when associated with all others. Further studies of are needed to fully characterize the association between O. carolinensis and S. marcescens, to determine the exact role of the bacterial associates in the nematode’s ecology and to assess this nematode’s applicability for agricultural insect pest management.}, number={2}, journal={BIOLOGICAL CONTROL}, author={Torres-Barragan, Andrea and Suazo, Alonso and Buhler, Wayne G. and Cardoza, Yasmin J.}, year={2011}, month={Nov}, pages={123–129} }
 @article{ye_torres-barragan_cardoza_2010, title={Oscheius carolinensis n. sp (Nematoda: Rhabditidae), a potential entomopathogenic nematode from vermicompost}, volume={12}, ISSN={["1388-5545"]}, DOI={10.1163/156854109x458464}, abstractNote={Summary – Oscheius carolinensis n. sp. (Rhabditidae) was recovered through the Galleria bait method from vermicompost produced in Raleigh, NC, USA. Morphological studies with light microscopy and scanning electron microscopy, as well as molecular analyses of the near-full-length small subunit rDNA gene (SSU), D2/D3 expansion segments of the large subunit rDNA gene (LSU) and internal transcribed spacer (ITS), revealed this as a new species, described herein as Oscheius carolinensis n. sp. The new species is characterised by a combination of characters including its unique DNA sequences, amphimictic reproduction, six separate lips with bristle-like sensilla, lateral field with four lines, leptoderan and open male bursa, arrangement of bursal papillae 1 + 1 + 1/3 + 3 + ph, evenly spaced first, second and third papillae, and separate spicules that are distally shaped like a crochet needle. Oscheius carolinensis n. sp. belongs to the Insectivorus-group and is closest to O. colombianus, O. chongmingensis n. comb., O. insectivorus and O. lucianii. A Bacillus-like bacterium appears to be associated with this nematode, based on our microscopic and SEM observations. Exposed Galleria larvae were killed within 5 days and numerous nematodes were recovered from the cadavers within 48 h. Preliminary tests revealed that this nematode is capable of infecting at least two other insect species (Pieris rapae and Tenebrio molitor) under laboratory conditions and therefore has potential as a biological control agent. The status of Heterorhabditidoides chongmingensis is discussed, the genus is proposed as a junior synonym of Oscheius ,a ndO. chongmingensis n. comb. is proposed.}, journal={NEMATOLOGY}, author={Ye, Weimin and Torres-Barragan, Andrea and Cardoza, Yasmin J.}, year={2010}, pages={121–135} }