Journal of Economic Entomology (2004) 97, 1531-1539

Roger I. Vargas, Jay Long, Neil W. Miller, Kathleen Delate, Charles G. Jackson, Grant K. Uchida, Renato C. Bautista and Ernie J. Harris (2004)
Releases of Psyttalia fletcheri (Hymenoptera: Braconidae) and sterile flies to suppress melon fly (Diptera: Tephritidae) in Hawaii
Journal of Economic Entomology 97 (5), 1531-1539
Abstract: Ivy gourd, Coccinia grandis (L.) Voigt, patches throughout Kailua-Kona, Hawaii Island, HI, were identified as persistent sources of melon fly, Bactrocera cucurbitae (Coquillett). These patches had a low incidence of Psyttalia fletcheri (Silvestri), its major braconid parasitoid natural enemy in Hawaii, and were used to evaluate augmentative releases of P. fletcheri against melon fly. In field cage studies of releases, numbers of melon flies emerging from ivy gourd fruit placed inside treatment cages were reduced up to 21-fold, and numbers of parasitoids were increased 11-fold. In open field releases of P. fletcheri into ivy gourd patches, parasitization rates were increased 4.7 times in release plots compared with those in control plots. However, there was no significant reduction in emergence of melon flies from fruit. In subsequent cage tests with sterile melon flies and P. fletcheri, combinations of sterile flies and P. fletcheri produced the greatest reduction (9-fold) in melon fly emergence from zucchini, Cucurbita pepo L. Reductions obtained with sterile flies alone or in combination with parasitoids were significantly greater than those in the control, whereas those for parasitoids alone were not. Although these results suggest that the effects of sterile flies were greater than those for parasitoids, from a multitactic melon fly management strategy, sterile flies would complement the effects of P. fletcheri. Cost and sustainability of these nonchemical approaches will be examined further in an ongoing areawide pest management program for melon fly in Hawaii.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article
Database assignments for author(s): Roger I. Vargas, Ernest J. Harris

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
Research topic(s) for beneficials or antagonists:
inundative/inoculative release
environment/habitat manipulation

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Zeugodacus cucurbitae	Squash/pumpkin (Cucurbita)	U.S.A. (Hawaii)
	Coccinia grandis (weed)		U.S.A. (Hawaii)
Psyttalia fletcheri (parasitoid)	Zeugodacus cucurbitae	Squash/pumpkin (Cucurbita)	U.S.A. (Hawaii)