On understanding and manipulating the hatching patterns of Diabrotica v. virgifera (Coleoptera: Chrysomelidae) eggs to improve the design of experiments

Diabrotica v. virgifera (Coleoptera: Chrysomelidae) is a well-studied pest of maize in North America and Europe. Many studies on its biology, behaviour or management rely individuals reared from either field-collected insect or on laboratory colonies. Naturally, D. v. virgifera eggs require an obligate diapause which can cause technical challenges such as a deceleration of research activities. To allow better planning of experimentation, we have investigated the survival and temporal hatching patterns of the pest`s eggs depending on diapause length as well as on post-diapause incubation temperature. Several series of laboratory assays revealed that eggs from diapausing populations hatch at highest rates and with most synchronized hatching start and peaks when overwintered at natural diapause length of eight to ten months or shorter down to five months (20 to 24 °C incubation temperatures). Comparably good hatching rates were found in eggs diapaused for only two months, but hatching patterns appeared more spread and variable. Diapause shorter than two months or longer than ten months reduced hatching successes, as did low incubation temperatures. Data matrices on egg overwintering survival, on the beginning, peak, duration and termination of egg hatching, as well as on hatching rates are provided for different diapause lengths and incubation temperatures of diapausing and, as a comparison, non-diapausing D. v. virigifera to support scientists choosing a colony which fits best their experimental setup and study conditions, as well as to properly plan such studies.