Development and Life Table ofAcalymma vittatum(Coleoptera: Chrysomelidae), a Vector ofErwinia tracheiphilain Cucurbits

Abstract

Acalymma vittatum (F.) is a cucurbit herbivore specialist and the vector of Erwinia tracheiphila (E. F. Smith) Holland, the causal agent of bacterial wilt in cucurbits. We determined the temperature-dependent development, survivorship, longevity, sex ratio, and fecundity of this vector. Egg-to adult development was modeled as y = e^{(0.225 × T)}−e^{[0.225 × 36.017 − (36.017 − T)/4.425]}, which suggests a maximum development rate of 4.29%/d at 32°C. Linear extrapolations suggest a lower threshold of 13°C and 432 DD needed for A. vittatum development. Survivorship of immature stages, which ranged from 60% at 27°C to 4% at 33°C, was strongly influenced by temperature, and no beetles survived to the adult stage at 36°C. Sex ratios did not deviate from 1:1. Adults were long-lived, with continuous egg production, which ranged from 0 to 4 eggs/female/d, after an 8-d preovipositional period at 27°C. Life table statistics were generated using these data. Together, these phenology models and life table information can be used to further develop integrated pest management programs for both A. vittatum and E. tracheiphila in cucurbits.