Submitted to: Florida Entomologist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 10/1/2002
Publication Date: 6/1/2003
Citation: Eitam, A., Holler, T., Sivinski, J.M., Aluja, M. 2003. Use of Host Fruit Chemical Cues for Laboratory Rearing of Doryctobracon areolatusa (Hymenoptera: Braconidae), A Parasitoid of Anastrepha spp. (Diptera: Tephritidae). Florida Entomologist. 86:211-216. Interpretive Summary: Tephritid fruit flies infest scores of fruits and vegetables, and are responsible for the erection of trade barriers that hinder the development of agricultural exports. The traditional means of control is the use of insecticide-bait sprays, but other techniques, such as the mass-rearing and release of parasitoids, are under development. However, some otherwise attractive species of parasitoids have proven difficult to mass-rear. Scientists at the USDA Center for Medical, Agricultural, and Veternary Entomology have developed a method of rearing the wide-spread parasitoid, Doryctobracon areolatus, in the laboratory. It was discovered that chemicals located on the surfaces of fruits stimulated egg-laying into Caribbean fruit fly larvae held in a cloth device that mimics an infested fruit. Further studies to identify the relevant chemicals may result in an economic means to produce large numbers of an important natural enemy.
Technical Abstract: Doryctobracon areolatus (Szepligeti) (Hymenoptera: Braconidae) is a common parasitoid of Anastrepha spp. (Diptera: Tephritidae). An efficient method of laboratory rearing is described: it incorporates chemicals from pear fruits into oviposition units. Production for the first and second generations was 12.1 and 9.3 progeny per female, respectively. Mean daily progeny production by second-generation females was between 1-2 progeny pe female for almost all ages from 9 to 22 days. A bioassay was designed to determine the source of chemical cues used for host location. Parasitoids were given a choice between two oviposition units: a positive control containing all possible cues, and a treatment unit. Response variables included the number of females active on the oviposition unit, and the number of progeny emerging from it. This experiment demonstrated that chemical cues derived from the host fruit, probably the peel, are involved in host location.