Diapause termination by low temperature storage and optimal rearing of post-diapause Chinese <i>Halyomorpha halys</i> populations

Abstract Introduction: The brown marmorated stinkbug , Halyomorpha halys (Hemiptera: Pentatomidae), is native to East Asia, but also a widely invasive crop pest worldwide. It is essential to obtain sufficient samples of H. halys for developing effective management strategies. Terminating diapause for overwinter populations of H. halys and optimizing food sources for their progeny are crucial strategies for maintaining and expanding the indoor experiment colony. However, there are rarely reports on the rearing and keeping lab population of H. halys in its native Beijing. Methods: In this study, we collected overwintering adults of H. halys in northern China, terminated their diapause via low temperature storage and reared their progeny. Results: We found that a 3-week low temperature storage at 9°C was sufficient to induce oviposition in some females, albeit at a low egg production (0.17 ± 0.06 egg masses/female) and after a prolonged pre-oviposition period (25.2 ± 0.9 d). As the low temperature storage duration was extended, per-female egg production progressively increased, while the pre-oviposition period concurrently decreased. Egg production peaked at 1.23 ± 0.08 egg masses/female, and the pre-oviposition period reached a minimum of 14.6 ± 0.7 d after 28 weeks of storage. The survival rate of adult females, however, decreased with prolonged storage time, reaching a minimum of 24 ± 3.3% after 33 weeks of storage. The relationship between low-temperature storage time (𝑥) and population egg production (PF) is described by PF = a (−0.0006x 2 + 0.0273x + 0.0130) (a: Number of insects introduced), and the maximum PF value was achieved by storing adults for 22.75 weeks. In laboratory rearing tests evaluating six diets for their effects on H. halys survival and egg production, both the highest nymphal survival rate (91.4 ± 3.3%) and the highest egg production (100.44 ± 8.05 eggs/female) occurred when stinkbugs were fed green beans, plus soybean seeds, and water. Conclusion: Optimal conditions for rearing H. halys collected in northern China were to maintain adults of the overwintering generation at 9 °C for 22.75 weeks, and then rear their progeny on green bean pods, supplemented with soybean seeds and water.