ARS | Publication request: Ultrastructural Responses in the Midgut of Hessian Fly Larvae Feeding on Resistant Wheat

Submitted to: NCB-ESA North Central Branch Entomological Society of America
Publication Type: Abstract Only
Publication Acceptance Date: February 15, 2009
Publication Date: N/A

Technical Abstract: The Hessian fly is present in all the wheat producing regions of the United States and is the most important insect pest in the southeastern soft-winter-wheat region. Genotypes of the pest that can overcome formerly resistant wheat continue to appear and pose a threat to wheat production. There is a need to better understand the mechanisms by which resistant plants are able to prevail over larval attack. The midgut is one of the major interfaces between the larval Hessian fly and its host plant. The object of the present study was to determine if ultrastructural changes occur in the midguts of larvae feeding on resistant wheat compared to larvae feeding on susceptible wheat and larvae experiencing starvation while removed from the plant. Results revealed that within three hours of initiating feeding on resistant wheat midgut microvilli were disrupted and after six hours microvilli were absent. The disruption of microvilli in larvae feeding on resistant wheat was similar to the disruption occurring in midgut microvilli of Drosophila larvae fed a diet containing 1% wheat germ agglutinin. These results indicate the midgut is a major target of toxic plant compounds and that lectins are probably major components of resistance.