- Pest Management: integrated pest management
Chauliognathus pensylvanicus (De Geer) and C. marginatus (Fabr.) are two of the most common species of cantharid beetles observed in agroecosystems in Virginia. Despite their regional abundance and early recognition and description in the 1700s, little is known about their life cycles and ecological role in agricultural systems. Immatures are generalist predators and have been recorded feeding upon soft-bodied insects such as lepidopteran larvae. Adults are attracted to and frequently visit flowering plants, where they eat nectar and/or pollen. Beyond those observations, little is known about these species. Because of their gravitation to flowering plants as adults and predatory behaviors as larvae, there is great potential to attract adults to an agricultural area with specifically planted flowers, provide choice habitat for egg laying in nearby crop plots, and encourage larvae to feed upon a wide variety of insect pests. To determine whether larval predation by Chauliognathus spp. could be valuable in an integrated pest management context, we sought to characterize the phenology of Chauliognathus species, examine their interactions with prey, and evaluate their responses to common agricultural IPM practices. We found that C. marginatus adults were active from early May to July and utilized multiple floral resources as food and harborages. In contrast to all previous literature, we found larvae foraging during daylight hours and in the upper canopy of sweetcorn and wildflower plants. Larvae readily consumed multiple food sources offered to them, including aphids, harlequin bug eggs, peanut butter, fruit, and meat. Finally, high mortality rates were observed when C. marginatus adults were exposed to both conventional and organic insecticides. In summary, the role of Chauliognathus spp. larvae and adults in agroecosystems is complex and warrants further study.
Objective 1: Characterize the phenology of Chauliognathus spp. in southwest VA agricultural systems.
Objective 2: Investigate the feeding behavior of Chauliognathus spp. larvae.
Objective 3: Evaluate responses of adult beetles to commonly used insecticides.