Journal of Nematology (2005) 37, 394-395

D.I. Shapiro-Ilan, R.J. Stuart and C.W. McCoy (2005)
Improved strains of Steinernema carpocapsae for control of the pecan weevil, Curculio cariae
Journal of Nematology 37 (3), 394-395
44th Annual Meeting, Society of Nematologists, Fort Lauderdale, Florida, 9-13 July, 2005
Abstract: The entomopathogenic nematode Steinernema carpocapsae has shown promise for control of adult stage pecan weevil, Curculio caryae, a key pest of pecan. In previous studies, the Italian strain of S. carpocapsae was found to be among the most virulent to C. caryae, but possessed poor environmental tolerance. In contrast, the DD-136 strain exhibited high levels of environmental tolerance but low virulence. Our objective was to determine the feasibility of developing improved strains of S. carpocapsae by transferring the nematode's bacterial symbiont from the Italian strain to the DD-136 strain, and through hybridization between the two wild type nematodes. Three modified strains were created: one through bacterial transfer alone and two hybrids through controlled crosses. We hypothesized that the improvement approaches would result in strains possessing high levels of environmental tolerance similar to DD-136 and virulence similar to the Italian strain. The hypothesis was supported in two out of three modified strains. Heat and desiccation tolerance in the three modified strains was more than 2.5 fold greater than the Italian strain and not different from the DD-136 strain, except one hybrid had lower heat tolerance than DD-136. Mortality of adult weevils from the modified strains was greater than from DD-136 (and similar to the Italian strain) two or three days after treatment. Overall, the results indicate that bacterial transfer and hybridization could be a valuable tool in improving biocontrol efficacy of steinernematids.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): David I. Shapiro-Ilan, Robin J. Stuart

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Curculio caryae	Pecan/hickory (Carya)
Steinernema carpocapsae/Xenorhabdus nematophila (entomopathogen)	Curculio caryae