Effect of Desert Termites on Herbage and Litter in a Shortgrass Ecosystem in West Texas

Abstract

The desert termite, Gnathamitermes tubiformans, is an important insect on rangelands in the southwestern United States. Population densities of this insect averaged 2139/m2 in the upper 30 cm of soil in a shortgrass community in West Texas over a 3-year period and reached a peak of 9127/m2 The live biomass of termites averaged 5.2 g/m2 and reached a peak of 22.21 g/m2. In a laboratory study, desert termite workers consumed 2.4% of their live body weight/day of dry buffalograss leaves. In field studies, control of desert termites with insecticide resulted in a 22% increase in standing crop of grass and a 50% increase in litter accumulation by the end of the second growing season after control was initiated. Termite-free plots had almost three times more litter than termite-infested plots after four growing seasons. Desert termites accounted for 55% of the disappearance of litter from the soil surface. Ranchers can expect higher population densities of desert termites and hence greater consumption of forage and litter during wet years.