Influences of temperature on homalodisca vitripennis (hemiptera: Cicadellidae) survival under various feeding conditions

Abstract

Survival of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae), was studied under various constant temperatures and feeding conditions. When provided a host plant (Citrus limon L. Burm. f.) to feed on during a 21-d trial, 100% mortality occurred at 0.1, 3.2, and 40.1°C, whereas an average of 7476% of adults survived in the 13.224.5°C range. When individually confined with moist cotton, adult longevity was greatest (16.3 d) at 13.3°C, but it was <3 d at -2.4 and 36.2°C. In a companion study comparing the presence versus absence of a host plant, the presence of a host plant was not a significant factor influencing survival at temperatures ≤7.8°C but was at temperatures ≥18.9°C. The relationship between temperature and survival was described by a nonlinear function that estimated the optimum temperature in each feeding regimen: no host plant or moist cotton (5.5°C), moist cotton (9.9°C), and accessible host plant (25.1°C). The model quantitatively predicted that H. vitripennis would survive longer periods at a wider temperature regimen when provided with a host plant than when provided with water alone (moist cotton) or when provided with neither plant host nor water. Our results suggest that continuous exposure to either low (<5°C) or high (>30°C) temperatures are detrimental for adult survival. Specifically, low temperatures caused early mortality because of inhibition of feeding activity and presumably this threshold lies between 7.8 and 13.2°C. Furthermore, this study clearly shows that temperature may influence the survival of H. vitripennis adults regardless of feeding regimens, and its implications for population dynamics are discussed. © 2009 Entomological Society of America.