Arthropod predation on aphids in a lucerne crop

Abstract

Predation on lucerne aphids (Acyrthosiphon spp.) by arthropod predators was investigated in late summer near Christchurch using a serological technique. Over 70% of the 4 most abundant predators found (Nobis kinbergii, Coccinella undecimpunctata, Micromus tasmaniae, and Phalangium opilio) gave positive precipitin reactions to antiserum. Feeding rates in the laboratory at 17-227deg;C ranged from 2.9 to 5.3 aphids/day. All predators were more abundant on lucerne at night than in the day and the nocturnally active P. opilio was shown to be a major aphid predator. This would not have been realised had only diurnal field sampling been undertaken.