Pink bollworm (Lepidoptera : Gelechijdae) and tobacco budworm, cabbage looper and beet armyworm (Lepidoptera : Noctuidae) larval mortalities fed on Bacillus thuringiensis (BG (R)) cotton pollens and pink bollworm adult mortality fed on sucrose soluti

• Author(s): Henneberry, Thomas; Jech, L.; Maurer, J.;
• Abstract: We fed pink bollworm (PBW), Pectinophora gossypiella (Saunders), tobacco budworm (TBW) Heliothis virescens (L), cabbage looper (CL), Trichophisia ni (Hubner), and beet armyworm (BAW), Spodoptera exigua (Hubner), pollens from cottons containing the Bollgard (R) (BG (R)) gene from Bacillus thuringiensis Kurstaki (Berliner) that produce the Cry1Ac toxin. PBW and TBW larvae were highly susceptible to the toxin in BG (R) pollen; whereas, results with BAW and CL were more variable, probably because both species are inherently less susceptible to the BG (R) toxin and because plant pollens may not be acceptable sources of food for either species. Enzyme Linked Immunosorbent Assays (ELISA) were positive for all BG (R) pollen cotton samples tested. We also collected cotton nectars from extrafloral and floral nectaries of BG (R) and non-BG (R) cottons. The occurrence of positive ELISAs for nectar was variable and unexplained. We fed moths 10% sucrose solutions alone or containing varying amounts of Cry1Ac formulated as MVP (R) II bioinsecticide (Mycogen Corporation, San Diego, CA). Feeding on the sucrose Cry1Ac solutions had no effect on male or female mortality or percentages of egg hatch. Moths fed less on sucrose solutions containing the Cry1Ac formulation compared to sucrose solutions alone. The inert ingredients in the MVP (R) II may be a factor influencing the results. ELISA positive and negative Cry1Ac moths were found, and our evidence suggests that PBW moths in some cases excrete the toxin after it is imbibed.
• Publication Date: Mar 2006
• Journal: Southwestern Entomologist