The use of germinating-seed baits to detect soil insect pests before crop sowing

Abstract

Germinating crop seed baits buried at shallow depth in moist fallow fields attracted soil-dwelling insects that adversely affect crop establishment. Presoaked grain sorghum seed attracted all potential pests found in soil samples in Central Queensland trials within 4-7 days from placement. Subterranean insects such as Tenebrionidae, Elateridae and Scarabaeidae larvae, black field earwig [Nala lividipes (Dufour)] and seed-harvesting ants (Pheidole sp.) were found near the seed and the seedling roots, while seedling shoots attracted surface-active feeders [wingless cockroaches (Calolampra elegans Roth and Princis), adult Tenebrionidae and Gryllidae]. The germinating seed bait method was superior to existing methods (insecticide-treated surface baits and soil sampling), both in the variety of species detected and in reduction in labour required. Germinating sorghum, wheat, sunflower and soybean seeds were equally attractive to wingless cockroaches, in 2 trials. Numbers of C. elegans/bait.day on germinating seed baits were correlated with numbers on insecticide-treated baits (r2 = 0.60, P(0.01).