Methods for Sampling Soil Surface Arthropods in Bush Beans: Which One Is the Best?

Mulching using organic matter has been shown to reduce the incidence of some insect pests. However, to evaluate effects of mulches on insects, reliable methods are needed for sampling insects that are active or living on the soil surface. An experiment was conducted in fall 2007 at the University of Florida Plant Science Research and Education Unit in Citra, FL. The objective was to compare different methods for sampling soil surface arthropods. The experiment was conducted on 25 small field plots. Three sampling methods (Berlese funnel, pitfall traps, and board traps) were used to sample the insects and other arthropods in each plot. Soil surface arthropods collected using these sampling methods were identified to family level under a dissecting microscope. The total number of taxa collected in Berlese funnel samples was always <3, and it was concluded that the Berlese funnel is not a practical sampling method for sandy soils in Florida. The greatest variety of different taxa were sampled using pitfall traps, which were superior to board traps for collection of greater numbers of many arthropods such as staphylinid beetles, chrysomelid beetles, springtails, grasshoppers, leafhoppers, flies, spiders, small parasitoid wasps, and small plant-feeding insects like aphids, thrips, and whiteflies. Board traps were better for sampling crickets, earwigs, and click beetles. Pitfall traps and board traps provided similar numbers of ants and carabid beetles. Overall, pitfall traps caught more taxa and greater numbers, and therefore were the most effective sampling method compared to board traps and Berlese-funnel methods.