Behavioural management techniques for broccoli and blueberry pests

Three agricultural pests, cabbage maggot fly Delia radicum (L.), cabbage aphid Brevicoryne brassicae (L.) and the blueberry maggot fly Rhagoletis mendax (Curran) were investigated for potential control through behavioral modification. Synthetic and organic mulches were evaluated in broccoli fields for control of D. radicum and B. brassicae as well as their impact on other insects. Soil Guard in its standard yellow color and enhanced with yellow paint were both significantly more attractive to B. brassicae than unmulched control plots. However, when Soil Guard was painted blue, a level of control comparable to that of diazinon was obtained for D. radicum. Weed fabric significantly reduced weed populations, but flea beetle levels in those plots were six times higher than controls. A sensitive trap-lure system was evaluated for monitoring blueberry maggot fly populations. Yellow, green, red, and blue spheres (9 cm diameter) were equal to or better than Pherocon AM yellow boards in attracting blueberry maggot flies. Traps baited with ammonia were significantly more attractive than unbaited traps. More female than male flies were captured on ammonia baited traps which is consistent with findings that Rhagoletis spp. female flies seek a protein source for egg maturation. Varietal trials and blueberry volatiles were evaluated for various blueberry cultivars. Eighteen highbush blueberry, Vaccinium corymbosum L., cultivars were evaluated for larval infestation by R. mendax. Significantly fewer maggots were found in berries of early-ripening cultivars, than in later maturing cultivars. The oviposition period of R. mendax is synchronized with the ripening dates of mid-season cultivars in Rhode Island. In 1997, we evaluated the attraction of blueberry maggot flies to blueberry volatiles at various load-rates. The effect of sphere sizes on the capture of bluebefly maggot flies was also investigated. R. mendax flies were attracted to a volatile blend at load-rates of 0.1 and 0.3 mg. Load-rates $\u3c$0.03 mg and $\u3e$1.0 mg were not significantly different from controls. More females than males were attracted to volatile blends and volatiles emanating from ripe blueberries. Among the 3 sphere sizes tested, the baited 9-cm sphere was the most efficient sphere and should be used for monitoring R. mendax