Submitted to: Agricultural and Forest Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/4/2007
Publication Date: 2/1/2008
Citation: Williams III, L.H., Hendrix, D.L. 2008. Comparing different floral resources on the longevity of a parasitic wasp. Agricultural and Forest Entomology. 10:23-28. Interpretive Summary: Plant bugs are serious pests of many crops, including cotton and soybean, in the United States. Beneficial insects are useful in killing plant bugs, but may require food sources, such as nectar and pollen, to maximize their potential. Thus, a better understanding of the nutritional requirements of beneficial insects has important implications for plant bug control. We compared the effects of flowers of several important non-crop host plants of a pestiferous plant bug on the lifespan of a beneficial insect. Our results indicate that the lifespan of the beneficial insect was not significantly increased by provision with flowers. No difference in lifespan was observed between gender of the beneficial insect, although females usually lived slightly longer than males. Chemical analysis of nectar revealed that the major components were sucrose, glucose, and fructose. This is puzzling, because these sugars are known to increase the lifespan of many types of beneficial insects. Thus, more work is warranted to better understand the mechanisms involved. However for the current study, we conclude that the flowers of some non-crop plants that serve as important hosts for plant bugs offer little or no benefit an important beneficial insect.
Technical Abstract: Nectar and pollen are natural means of enhancing the longevity and reproductive success of beneficial insects. Pest suppression strategies that use vegetation management may eliminate floral resources, and thus an important food source for beneficial insects. Successful integration of biological control with other strategies, such as cultural control, depends on detailed knowledge of the insect’s nutritional physiology and ecology. We compared the effects of floral resources of several important non-crop host plants of a pest, Lygus lineolaris, on the longevity of its natural enemy, Anaphes iole. Median longevity of A. iole wasps provisioned with floral resources (Erigeron annuus, Oenothera speciosa, Lamium amplexicaule, and Capsella bursa-pastoris) ranged from 1.274-3.242 days, and did not differ from wasps in the distilled water only control (1.464-2.812 days). Median longevity of wasps provisioned with distilled water+sucrose was greater (5.301-12.46 days) than in other treatments. No difference in longevity was observed between gender, although females usually lived slightly longer than males. High-performance anion-exchange chromatography analyses of O. speciosa floral nectar revealed that the major carbohydrate components were sucrose, glucose, and fructose. Our results indicate that the floral resources of some non-crop plants that serve as important hosts for population increases of L. lineolaris offer little or no benefit to A. iole.