The Ecology and Bioenergetics of the Acridid Grasshopper, Bootettix Punctatus on Creosotebush, Larrea Tridentata, in the Northern Mojave Desert

An 5—yr investigations was conducted of the population structure and bioenergetics of the host specific acridid, Bootettix punctatus, on creosotebush, Larrea tridentata, in the northern Mojave Desert of southern Nevada. Maximum densities ranged from 330—1360 insects/ha in mid—summer on a shrub density of 1000 plants/ha. Energy used for respiratory maintenance accounted for 55—68% of the energy assimilated by the populations. Assimilation was 20—23% of the 207—1681 J/m2 energy ingested per season. The estimated proportion of the host plants annual leaf biomass consumed during the first 3 yr of this study ranged from 0.8—1.9%. Nutrient availability in Larrea as a function of available soil moisture is suggested as a possible factor influencing the survivorship of early instar nymphs and of the population as a whole. Normal effects on the host plant due to phytophagy are probably negligible but, under certain climatic conditions, phytophagy by Bootettix in the late summer may stimulate primary production or improve the drought resistance of the shrub by defoliation.