Dragonflies as potential biological control on farms: prey assessment using a DNA approach

View the project final report

Commodities

• Agronomic: corn, soybeans, alfalfa

Practices

• Pest Management: biological control, integrated pest management
• Production Systems: agroecosystems
• Sustainable Communities: sustainability measures

Dragonflies and damselflies are opportunistic predators as adults. However, the potential for adult dragonflies as biological control agents in agroecosystems has been understudied, in part because their diet is not fully understood. New molecular techniques using Next Generation Sequencing (NGS) of fecal pellets can help researchers better understand dragonfly diet. The goal of this study is (1) to compare richness and abundance of assemblages of adult species of dragonflies and damselflies among farms and crops and (2) to compare prey composition using next generation sequencing of Erythemis simplicicollis (eastern pondhawk) feces between upland farm habitat and near water habitat. Visual encounter surveys will be conducted at four University of Maryland farms in central and western Maryland twice a month during the summer of 2021, and fecal samples will be collected from the target species once a month. Fecal samples will be prepared for DNA analysis by GENEWIZ, and sequences provided by GENEWIZ will be compared to the genetics sequence database GenBank. Results of this study will be published in local agricultural newsletters and pamphlets and an agricultural peer-reviewed journal, as well as presented at several professional meetings.  By determining what pest species dragonflies feed on in field crops, we hope to highlight the importance of adult dragonflies as generalist natural enemies in agriculture in order to persuade farmers to encourage dragonfly populations, and the associated predation, on their farms. 

The overall goal of this study is to better understand Odonata community composition, prey selection and their potential for pest suppression in agroecosystems. This goal can be divided into two research objectives:

1. To compare richness and abundance of assemblages of adult species of dragonflies and damselflies among farms and crops.
2. To compare prey composition using next generation sequencing of Erythemis simplicicollis (eastern pondhawk) feces between upland farm habitat and near water habitat.