The effect of the number of simultaneously ovipositing females on progeny sex ratio of three Homalodisca coagulata egg parasitoids, Gonatocerus ashmeadi, G. triguttatus, and G. fasciatus was investigated in the laboratory. When one female Gonatocerus parasitoid was present, progeny production was strongly female biased producing similar to 1 male:8 females, 1:14 and 1:9 for G. ashmeadi, G. triguttatus and G. fasciatus, respectively. Increasing the number of simultaneous ovipositing females from I to 3, significantly increased percentage of male offspring by up to 61% for all three Gonatocerus species. Overall percentage male offspring ranged from 31-34%, and did not significantly differ among species. Overall mean percentage parasitism by G. ashmeadi was up to 16% higher compared with G. triguttatus and G. fasciatus, whereas, average clutch size and mean progeny production was more than twofold higher for G. fasciatus when compared with G. ashmeadi and G. triguttatus. Additional laboratory trials with only G. ashmeadi demonstrated that when H. coagulata egg masses consisted of 2-13 eggs, 67-100% of females allocated one male offspring per egg mass. When one egg mass was presented to five female G. ashmeadi searching concurrently, male offspring was up to 22% higher compared with male offspring from host eggs exposed to one female G. ashmeadi. Experiments indicated that allocation of male eggs was not influenced by constant female-to-female contact for 19 h prior to host exposure, and female G. ashmeadi did not alter allocation of male eggs when sibling and non-sibling conspecifics were contesting host egg masses. The economic significance for mass rearing is substantial. For G. ashmeadi at 2003 production costs and under optimal conditions, estimated cost per female was $1.42, under suboptimal conditions, cost per female increased to $4.51; a 218% increase in production cost per female parasitoid. (c) 2006 Elsevier Inc. All rights reserved.

The effect of five different food resources (Coccus hesperidum honeydew, honey-water, Lobularia maritima, Fagopyrum esculentum and water only) on the longevity, fecundity, and progeny fitness of female Gonatocerus ashmeadi, an egg parasitoid of the glassy-winged sharpshooter (Homalodisca vitripennis) was investigated in the laboratory. Female G. ashmeadi survived 208-405% longer (up to 11.7 days longer) when fed C hesperidum honeydew, honey-water, L. maritima and F. esculentum compared with water only. Similarly, all food treatments resulted in up to 378% more progeny (up to 80 more total progeny) than those females provisioned with water only. Mean percentage female progeny ranged from 70 to 81% and did not significantly differ between food treatments. The highest daily fecundity (2229 progeny) occurred on the first day of oviposition for each food treatment and generally declined as female G. ashmeadi aged. Females deposited 61-100% of offspring within the first 5 days, after which, daily fecundity usually declined to 0-6 offspring per day. For all experimental diets except L. maritima, the number of male progeny oviposited remained relatively constant over time (similar to 2 males per oviposition bout) but the proportion of males oviposited increased as female G. ashmeadi aged, as oviposition rates declined and fewer female eggs were subsequently laid. There was a strong positive correlation between hind tibia length (HTL) and total progeny produced by G. ashmeadi fed honey-water. There was no correlation between HTL and longevity of female G. ashmeadi fed honey-water. Mean HTL of G. ashmeadi progeny did not significantly differ between food treatments. Estimated progeny fecundity based on HTL, indicated that offspring produced by females provided with water only was 12-15 eggs or 9-12% lower than females that had access to food resources. This difference was not statistically significant. Female progeny that were oviposited by females 9-13 days of age with access to food resources were significantly larger and contained on average 14-17 more eggs than those female progeny resulting from eggs deposited by females 1-8 days of age. (c) 2006 Elsevier Inc. All rights reserved.

The effect of dietary supplements on the longevity of mate and female Gonatocerus ashineadi, G. triguttatus and G.fasciatus (Hymenoptera: Mymaridae), was determined in the laboratory. Treatments included: water only, 3:1 honey-water solution, floral and extra-floral nectars from five different plants (excised stems from Fagopyrum esculentum, Lobularia maritima, Phacelia tanacetifolia, Anethum graveolens and Vicia faba), honeydew from Coccus hesperidum and Homalodisca vitripennis (formally H. coagulata), a commercially available food supplement (Eliminade) and citrus foliage. Additionally, the sugar composition of each food resource was determined using HPLC and whole flower extracts. Honey-water and F esculentum nectar significantly increased longevity of male and female G. ashmeadi, G. triguttatus, and G. fasciatus up to 1860%, 1323% and 1459%, respectively, when compared with water. For both sexes and all three parasitoid species, survival on citrus foliage, H. vitripennis excrement, and P. tanacetifolia flowers was equivalent to that on water only. The longevity of G. ashmeadi and G. triguttatits was up to 539% higher on Eliminade compared with water only, however there was no significant effect of Eliminade on survival of G. fasciatus. Coccus hesperidum honeydew increased survival times up to 665% for all mymarid species compared with citrus foliage alone. HPLC analysis indicated that food resources most beneficial to Gonatocerus parasitoids possessed a high proportion of glucose (up to 44%) and fructose (up to 53%), suggesting that sucrose may not be as important for parasitoid survival. Citrus and P. tanacetifolia flowers contained favorable proportions of glucose and fructose, but the inability of Gonatocerus spp. to benefit from this may be related to flower morphology which could prevent access to nectar. (c) 2006 Elsevier Inc. All rights reserved.

The glassy-winged sharpshooter (GWSS) is an introduced pest that spreads the bacterium Xylella fastidiosa, which causes a variety of diseases such as Pierce’s disease in grapevines and leaf scorch in oleanders. GWSS has been established in Southern California since about 1990 and has also successfully invaded French Polynesia, Hawaii and Easter Island. Researchers from UC, the U.S. Department of Agriculture and the California Department of Food and Agriculture have introduced parasitic wasps for the biological control of GWSS. Four parasitoids from the southeastern United States have been released and appear to be establishing in Southern California. Parasitoids from Argentina are also being evaluated in quarantine but have not yet been released.