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Utilization of starch matrices for development of corn rootworm-specific semiochemical/insecticide delivery systems: Potential for adult suppression
Abstract
Starch matrix technologies were utilized to create controlled release semiochemical/insecticide formulations that selectively attract and kill corn rootworm (CRW) adults over time in field corn. Semiochemicals and insecticides were incorporated into starch borate (SBM) and pregelatinized starch (PGM) matrices. Chemical analyses of SBM granules indicated that variable pH environments created during formulation may have degraded some volatile attractants and carbaryl. The PGM is inert and could be used to encapsulate all compounds tested. Semiochemicals successfully encapsulated in the SBM were released at rates attractive to CRW beetles for varying lengths of time in field corn. Western CRW adults were concentrated in field plots following application of SBM granules formulated with semiochemicals and carbaryl, but mortality was low despite observed beetle feeding. Laboratory bioassays indicated that carbaryl, methomyl, or carbofuran formulated in the PGM, and carbofuran formulated in the SBM, will effectively kill CRW beetles ($>$90% mortality/24 h). When placed in traps in the field, PGM granules formulated with semiochemicals and carbaryl attracted and killed CRW beetles. Mortality of western and southern CRW beetles following application of starch encapsulated semiochemical/insecticide granules was comparable to mortality following a broadcast application of Sevin XLR Plus while utilizing 90% less insecticide. Season-long studies indicated that CRW attraction to starch encapsulated semiochemicals decreased during corn flowering. Starch encapsulated semiochemical/insecticide formulations are more effective when placed at or above corn ear height than at ground level. Starch granules broadcast-applied in the field had variable impact on adult stages of the non-target species Coleomegilla maculata lengi, and Harpalus pennsylvanicus. Impact of starch formulations on both species was decreased by coating granules with cucurbitacin. Results suggest that the SBM and PGM can be used to create species specific semiochemical/insecticide delivery systems that are palatable to CRW adults. These delivery systems may have potential in future corn rootworm management programs.
Subject Area
Entomology|Agronomy
Recommended Citation
Weissling, Thomas John, "Utilization of starch matrices for development of corn rootworm-specific semiochemical/insecticide delivery systems: Potential for adult suppression" (1990). ETD collection for University of Nebraska-Lincoln. AAI9108253.
https://digitalcommons.unl.edu/dissertations/AAI9108253