Contact stimulants from Heliothis virescens that influence the behavior of females of the tachinid, Eucelatoria bryani

Factors acting at contact or close range affected the behavior associated with host seeking of females, but not of males, of the tachinid, Eucelatoria bryani Sabrosky. Females were arrested by components of larvae of Heliothis virescens (F.) and by a dichloromethane extract of okra leaves. A hexane of H. virescens frass and a chloroform-methanol extract of H. virescens larvae were both active. In addition to chemicals, shape and size were involved because females were arrested by small inert objects the size of H. virescens larvae and frass.