Submitted to: Florida Entomologist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/21/2009
Publication Date: 1/12/2009
Citation: Palenchar, J., Holler, T., Moses-Rowley, A., Mcgovern, R., Sivinski, J.M. 2009. Evaluating the use of irradiated caribean fruit fly (Diptera:Tephritidae) larvae for laboratory rearing of Doryctobracon areolatus (Hymenoptera: Braconidae). Florida Entomologist. 92(4)535-537. Interpretive Summary: Fruit fly pests attack hundreds of fruits and vegetables and cause trade restrictions wherever they occur. One means of suppressing their numbers is the mass-rearing and release of large numbers of parasitoids and this process can be made more efficacious by irradiating the hosts thereby removing the danger of releasing fertile flies at the same time. Scientists at the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida, in collaboration with colleagues from APHIS-PPQ irradiated fruit fly larvae to see if an important New World natural enemy could be reared on treated hosts. Radiation had no effect on the production of the parasitoid and so can be adopted by biological control programs.
Technical Abstract: Mass-rearing and augmentative release of hymenopterous parasitoids has been a component of area-wide management programs for several tephritid fruit flies, including pestiferous species of the genus Anastrepha (Cancino and Montoya, in press). Laboratory rearing of Doryctobracon areolatus (Szepligeti), a wide-spread braconid larval-prepupal parasitoid of Anastrepha fruit flies, was first done in the United States in Florida in the late 1960’s as part of an effort to biologically control the recently introduced Caribbean fruit fly, Anastrepha suspensa (Loew) (Baranowski et al. 1993; Cancino et al., in press). Although releases of D. areolatus for management of the A. suspensa in Florida have ended, laboratory rearing of D. areolatus has resumed in order to make parasitoids available to Caribbean locations interested in the establishment of fruit fly natural enemies (Holler, personal communication). The process of rearing, transporting, and releasing parasitoids can be simplified if parasitoids are reared in fruit fly larvae that have been irradiated (Sivinski and Smittle 1990). Irradiated hosts will not develop into adult flies, but are capable of supporting the development of a number of fruit fly specific braconid parasitoids, including Doryctobracon crawfordi (Viereck) (Aluja et al., in press; Cancino et al., in press). In addition to producing pure parasitoid cohorts for immediate release, parasitoids can be moved as pupae without transferring the pest. The following report describes the first attempt to irradiate A. suspensa larvae for the purpose of rearing D. areolatus. We describe its affects on the development of A. suspensa, rates of parasitism and parasitoid sex ratio.