Regulation of Migratory Flight by Juvenile Hormone Mimic and Inhibitor in the Western Corn Rootworm (Coleoptera: Chrysomelidae)

Abstract

Adult mated and virgin females were dosed with a juvenile hormone (JH) agonist or antagonist to alter their intrinsic levels of juvenoid compounds. Of 468 females tested, 252 flew, and migratory flight behavior was observed in 145 (31%). No migratory flights were undertaken by untreated virgins. Females treated with juvenile hormone mimic (JHM) and inhibitor (AJH) flew both trivial and sustained flights that were significantly longer in duration and distance than those of controls, but age displacement of peak flight activity varied according to treatment and mating status. There seems to be a definitive window of migratory flight activity in the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, that can be temporally displaced by JHM and AJH treatment. Ovarian development was negatively correlated with migratory flight activity, which substantiates the inverse relationship between flight and reproduction. JH moderates the considerable flight capabilities of the WCR, permitting adaptation of this species to a dynamic, agricultural ecosystem.