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Tolerance of eCry3.1Ab in reciprocal cross offspring of eCry3.1Ab-selected and control colonies of Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae)
- Geisert, Ryan W., Ellersieck, Mark R., Hibbard, Bruce
- Journal of economic entomology 2016 v.109 no.2 pp. 815-820
- Diabrotica virgifera virgifera, Zea mays, adults, artificial diets, corn, females, greenhouse experimentation, growth chambers, insecticide resistance, larvae, lethal concentration 50, males, progeny, rearing, reciprocal crosses, rootworms, seedlings, statistical analysis, toxicity
- Two reciprocal cross colonies were created by separating virgin western corn rootworm, Diabrotica virgifera virgifera LeConte, males and females from both a selected laboratory colony that was being reared on eCry3.1Ab-expressing corn (Zea mays L.) and a control colony reared on its near isoline. Females from the selected colony were paired with males of the control colony and vice versa to create both a selected female by control male colony (Sel') and control female by selected male colony (Con'). Both colonies along with their parental colonies (eCry3.1Ab-selected and control) were evaluated on eCry3.1Ab-expressing corn and it’s near isoline in greenhouse experiments, seedling assays in growth chambers, and diet toxicity assays with increasing doses eCry3.1Ab being applied to the surface of artificial diet for western corn rootworm larvae. Statistical analysis of larval recovery, adult recovery, and plant root damage in greenhouse experiments showed no significant colony × corn interaction but did show a significant main effect of corn type. Similar results were seen for larvae recovery from the seedling assays with only a significant main effect of corn type being found. Results from the diet toxicity assays showed the control colony to have a significantly lower LC50 value than the selected and cross colonies and a significantly lower EC50 than the selected and Con' colonies. Calculations of dominance values (h) of eCry3.1Ab resistance traits from seedling assays indicated that the two reciprocal cross colonies to have a dominance value (h) of approximately 1, suggesting dominance of the eCry3.1Ab resistance trait. Data from these experiments help to showcase how eCry3.1Ab resistance traits can be transferred between resistant and susceptible western corn rootworms.