A Simple and Effective Method for Capturing Viable Adult Blueberry Maggot Flies, Rhagoletis mendax (Diptera: Tephritidae)

Abstract

The blueberry maggot fly, Rhagoletis mendax Curran, (Diptera: Tephritidae) is a widely distributed pest of lowand highbush blueberries (Vaccinium angustifolium Aiton and Vaccinium corymbosum L., respectively) (Vacciniaceae) within the northeastern and midwestern United States, as well as Canada. Given its economic importance, the fly has been the target of considerable research with respect to the development of monitoring and control strategies within the context of integrated pest management (Prokopy and Coli, 1978; Liburd et al., 1998a, b, 2000). Several attempts have been made to develop and refine blueberry maggot fly monitoring programs in order to forecast the presence of infestations in commercial blueberry plantings (Liburd et al., 1998a, 2000). The current monitoring practices employed by commercial growers of lowand highbush blueberries involve the deployment of ammonium-baited Pherocon AM yellow sticky panels or green and red sticky spheres (Prokopy and Coli, 1978; Liburd et al., 1998a). Such practices allow growers to detect fly emergence for more accurate timing of sprays. The blueberry maggot is also a member of the R. pomonella (Walsh) sibling species complex and has been used as part of a long-running study system by evolutionary biologists for investigating the mechanisms of speciation in sympatry (Feder and Bush, 1989). The blueberry maggot fly completes larval development inside blueberry fruit and undergoes an obligate annual diapause, making laboratory-rearing difficult. To our knowledge, a continuously-reared laboratory colony of blueberry maggot does not exist. The blueberry maggot has been the subject of many laboratory studies investigating toxicity of potential insecticides (Ayyappath et al, 2000; Stelinski et al, 2001; Liburd et al, 2003). Other laboratory investigations have focused on the antennal sensitivity and oviposition preference of blueberry maggot flies with reference to host-plant related chemical cues (Frey and Bush, 1996). In these laboratory studies, the investigators have relied on the use of adult flies reared from larvae collected the previous year from infested fruit. We describe here a simple and effective method for capturing viable male and female blueberry maggot fly adults in both abandoned and commercial highbush blueberry Vaccinium spp. plantations. Such field-captured, live blueberry maggot flies could be used in the laboratory for toxicological studies, electrophysiological investigations, behavioral assays or in genetic analyses of specific populations. Potentially, this technique could also be adopted for other tephritid species of broad interest.