Subterranean Termites (Insecta: Isoptera) Sampled in Sandy and Sandy-Clay Soils at Minas Gerais Cerrado, Brazil

摘要

Subterranean termites are important pests at the initial eucalyptus growth stage and, thus, might be targeted for control. However, sampling methods to determine these insects' infestation degree in cultivated areas are understudied. This paper aimedto study the spatial distribution and identification and samplingplans for subterranean termites at eucalyptus plantations, in cerrado areas of Joao Pinheiro Municipality, Minas Gerais State, Brazil. Eucalyptus plot areas were divided into continuous parcels of 50 x 50m and corrugated cardboard baits installed in the center of each, where termite individuals were counted. Syntermes spp. foraging holes were counted in circular parcels of 20m radius around each bait. Termite spatial distribution was determined with their individuals colleted by the baits and by the number of Syntermes foraging holes. Optimal random sampling number was calculated through bait data and Syntermes holes were labeled as absent or present. Six different subterranean termite species were colleted with the cardboard baits and they presented a spatial aggregated distribution at the eucalyptus plantation. Based on the results, the number of parcels for subterranean termite sampling with cardboard baits should be 1.36 to 0.18, andthe area for Syntermes foraging hole counts should be 5 to 0.27 parcels per hectare, depending on soil type and an estimation error from 10 to 25%.