Skip to main content
ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Chemistry Research » Research » Publications at this Location » Publication #74153
Title: HOST RECOGNITION BY THE SPECIALIST ENDOPARASITOID MICROPLITIS CROCEIPES (HYMENOPTERA:BRACONIDAE)

Author
item ROESE, URSULA - UF, ENTOMOLOGY DEPT.
item ALBORN, HANS - COLLABORATOR
item MAKRANCZY, GYORGY - HUNGARIAN ACADEMY OF SCI.
item Lewis, Wallace
item Tumlinson Iii, James

Submitted to: Journal of Insect Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/14/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Parasitic wasps that attack and sting moth caterpillars are effective, but often unreliable, agents for biological control of insect pests of agricultural crops. In order to develop ways to increase the reliability of these biological pest control organisms, scientists at the USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL, and Insect Biology/Management Systems Research, Tifton, GA, have studied the chemical and behavioral factors that enable these wasps to find the caterpillar pests. They have discovered that the wasps use odors from caterpillar waste products as cues for caterpillar location. Furthermore, these odors are related to the diet on which the caterpillars feed. Cotton bollworms, fall armyworms and beet armyworms fed on cotton were found with greater efficiency by the wasps than those fed on artificial diet. These results clearly demonstrate that plants attacked by caterpillars play an active and important role in recruiting natural enemies of their attackers. This information will be useful in developing more resistant crop varieties and biological control methods to combat insect pests in effective and environmentally safe ways.

Technical Abstract: The specialist parasitoid Microplitis croceipes (Cresson) can only parasitize larvae of the Helicoverpa and Heliothis genera. To be successful in their search for hosts, the ability to distinguish hosts from non-hosts feeding on the same plant is crucial. We conducted flight tunnel experiments with volatiles released from frass produced by host (Helicoverpa zea Boddie) and non-host larvae (Spodoptera exigua Hubner and Spodoptera frugiperda J. E. Smith), and short range walking experiments with host and non-host larvae to determine the parasitoid's ability to distinguish between host and non-host larvae, and how this ability is affected by the diet of the larvae. M. croceipes appeared to be able to distinguish between volatiles released from frass of different lepidopteran species fed on cotton prior to landing on the odor source. However, a contact experience with frass of cotton-fed host larvae appeared to be critical for this ability. Wasps that had antennated frass of host larvae fed pinto bean diet were equally attracted to frass of host and non-host larvae fed on pinto bean diet. In short range walking experiments, wasps located cotton-fed host larvae faster than diet-fed larvae, regardless of their experience. Wasps that had antennated frass of cotton-fed host larvae were less attracted to cotton-fed non-host larvae when compared to host larvae, and preferred to sting the host larvae. Plant-related volatiles in host frass and larvae appear to play a major role in the successful location of host larvae.