Development, Survival, and Hatching Periodicity of Lygus hesperus (Hemiptera: Miridae) Eggs under Constant and Variable Temperatures

Abstract  The microclimate within western cotton (Gossypium spp.) seems favorable for the western tarnished plant bug (Lygus hesperus Knight) (Hemiptera: Miridae), provided adequate soil moisture is available. Diminishing water supplies and increasing costs in the West will likely change irrigation practices and induce at least periodically unfavorable conditions for L. hesperus. Knowledge of L. hesperus thermal ecology has been limited to constant temperatures for which relevance to variable temperature environments is unknown. Eggs of L. hesperus were reared under low (mean = 15°C), medium (mean = 22°C), or high (mean = 29°C) constant (±<0.5°C) or diurnally fluctuating (±8°C) temperatures. Developmental time and survival were similar between constant and variable regimes at the medium temperature. In contrast, variable low temperatures hastened egg development and increased survival, whereas variable high temperatures delayed development and reduced survival compared with constant regimes. Within the st...