On understanding and manipulating the hatching patterns of Diabrotica virgifera virgifera eggs to improve the design of experiments

Abstract

AbstractDiabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae) is a well‐studied pest of maize (Zea mays L., Poaceae) in North America and Europe. Many studies on its biology, behaviour, or management rely on individuals reared from either field‐collected insects or laboratory colonies. Naturally, D. v. virgifera eggs require an obligate 8–10‐month 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 post‐diapause incubation temperature. Laboratory assays revealed that the highest hatching rates and most synchronized hatching times in a wild diapausing population occurred when eggs were overwintered at the natural diapause length (8–10 months) or shorter (5–7 months) and then incubated at 20–24 °C. Eggs diapaused for only 2 months showed comparably good hatching rates, but hatching patterns appeared more variable. Diapause of <2 or >10 months reduced hatching success, as did low (16 °C) incubation temperatures. For comparison, a well‐studied non‐diapausing laboratory colony was assessed as well. Data matrices on egg overwintering survival, the start, peak, duration, and end of egg hatching, as well as hatching rates are provided for various diapause lengths and three incubation temperatures for both populations. This information will support scientists in choosing a D. v. virgifera colony that fits best their experimental set‐up and study conditions, as well as in optimally planning such studies.