Effect of temperature on fecundity, development, and emergence of the invasive ambrosia beetle Euwallacea kuroshio (Coleoptera: Scolytinae).
The Kuroshio shot hole borer (KSHB) Euwallacea kuroshio is an invasive ambrosia beetle pest in Southern California, where it causes Fusarium dieback in a number of different host tree species. Since its discovery in California in about 2014, the KSHB has established or been identified across a wide geographic range along the California coast, spanning north from the Mexican border to San Luis Obispo. KSHB were reared at temperatures ranging from 16 to 32°C to determine the effect of temperature on development and emergence rates, brood size, and colonization success. The highest total emergence and number of successful colonies occurred when KSHB was reared at 28°C. Mean days until first offspring emergence decreased as temperature increased up to 30°C, after which emergence ceased. The thermal constant was estimated to be 318 degree-days. Using this approximation in conjunction with weather data from the California Irrigation Management Information System, we predict the annual number of generations of KSHB in several locations across its invasive range in California. Results can be used to predict the timing and number of generations in other invaded areas, as well as estimate the range of this pest.