Biological Control Potential of Three Species of Nymphal Odonates against Polypedilum nubifer (Skuse), a Nuisance Midge (Diptera: Chironomidae)

Abstract

The predation rates of nymphs from three odonatan species attacking larvae of the nuisance midge Polypedilum nubifer were determined in the laboratory. The dragonfly Hemicordulia tau was the most voracious, consuming up to 55 midge larvae/day at a prey density of 10,000/m2 after 48 h starvation. Under similar conditions, the dragonfly Orthetrum caledonicum consumed up to 29 midge larvae/day, and the damselfly Xanthagrion erythroneurum took up to 43 midge larvae/day. However, on the third successive trial these figures fell considerably to 12, 10 and 2 midge larvae/day, respectively. Overall, the laboratory trials show sufficient promise to justify field studies of these predators to assess their potential for containing midge larvae numbers in natural wetlands, in conjunction with procedures to control nutrient enrichment.