Territory Selection in a Desert Grasshopper: The Maximization of Conversion Efficiency on a Chemically Defended Shrub

SUMMARY (1) Ligurotettix coquilletti is an oligophagous grasshopper found mostly on creosotebush, Larrea tridentata, in the deserts of south-western North America. Adult males defend individual host-plants as mating territories. Preferred shrubs, used as territories each year, are distinguished by low concentrations of the phenolic compound nordihydroguaiaretic acid (NDGA). (2) Long-term growth experiments conducted in situ showed that adult males suffered high mortality on 'avoided' shrubs due to starvation and consequent desiccation. (3) Mortality of females did not differ between preferred and 'avoided' shrubs, but between 7 and 14 days post-eclosion females grew at significantly slower rates on avoided shrubs.