|Andrews, John Jr.|
Submitted to: Biocontrol
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2005
Publication Date: 9/5/2006
Citation: Sime, K.R., Daane, K.M., Andrews, J.W., Hoelmer, K.A., Pickett, C.H., Nadel, H., Johnson, M.W., Messing, R.H., 2006. The biology of Bracon celer, as a parasitoid of the olive fly. BioControl. 51:553-567. Interpretive Summary: Olive fly is a key pest of olives in the Mediterranean countries and recently invaded California, where it poses a serious threat to the olive industry. The cost of insecticides and prevalence of infested trees in suburban and rural landscaping which act as reservoirs for reinvasion argue for the development of sustainable means of control. Also, successful biological controls that are established for scale pests in California olives may be disrupted by insecticides applied for olive fly. A classical biological control program for olive fly was initiated in 2002. Importation efforts included foreign exploration for parasitoids of olive fly in Africa. Bracon celer is a common parasitoid attacking the olive fly in the fly’s native range in south and east Africa. This parasitoid species has attracted interest as a potential biological control agent but previous attempts to rear it in the laboratory for study and field release were not successful. A small number of B. celer were imported to California to establish a culture for studies to improve rearing techniques and determine its potential as a biological control agent for the olive fly in California and elsewhere. We report here on its biological characteristics and a rearing methodology. Its release in California is pending evaluation for non-target risks and a comparison of its efficacy with the performance of other imported parasitoid species.
Technical Abstract: Life-history trials were conducted in the laboratory for Bracon celer Szépligeti (Hymenoptera: Braconidae), reared on the olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae). Female B. celer oviposit preferentially on late third-instar olive fly larvae. The parasitoid larva develops as an idiobiont, solitary ectoparasitoid. Mean development time (egg to adult) was 23 (± 2 SE) days at 25'C. The mean longevity of adult wasps provided honey and water was 38.5 (± 15.0 SE) days, 19.5 (± 6.4 SE) days when provided hosts, honey, and water, and only 4.5 (± 0.9 SE) days when no food or water was provided. Adults were able to oviposit within one day of emergence. In an experimental trial, females produced an average of 9.7 (±7.2 SE) progeny during their lifetimes. Production levels in the insectary colony suggested much higher levels of fecundity, however, and the discrepancy may be a consequence of constraints on oviposition behavior imposed by the experimental design. The results are discussed with respect to insectary production methods and the potential use of B. celer as a biological control agent for olive fly in California.