Department of Entomology, Rutgers University, Bridgeton, NJ, USA.
Department of Entomology and Plant Pathology, North Carolina State University, Mills River, NC, USA.
Environ Entomol. 2021 Dec 17;50(6):1400-1406. doi: 10.1093/ee/nvab089.
Understanding cues for diapause termination in insects can be valuable in predicting phenological events in their lifecycles. Once identified, such cues can be utilized as a biofix, the point at which the majority of individuals within a population begin to accumulate degree days. We investigated the impact of photoperiod on completion of reproductive diapause in the invasive eastern North American population of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), by exposing diapausing females to varying light regimes in otherwise identical environments. The critical photoperiod estimated to initiate reproductive development in at least 50% of the potential reproductive population was 13.0-13.5 h, with increasing photoperiods coinciding with increased probability of females reproducing, earlier time to first oviposition, and higher rates of fecundity. These data on the species' response to photoperiod are in agreement with previous modeling that predicted the twin constraints of photoperiod and temperature on H. halys reproduction prevents populations that undergo diapause from producing more than two generations annually anywhere within the continental U.S. However, the facultative nature of diapause in H. halys leaves open the possibility that sub-populations may not enter diapause in some conditions, potentially allowing for additional annual generations.
了解昆虫滞育终止的线索对于预测其生命周期中的物候事件非常有价值。一旦确定了这些线索，就可以将其用作生物标记，即种群中大多数个体开始积累度日数的时间点。我们通过在其他条件相同的环境中，让处于繁殖滞育期的雌性臭虫暴露在不同的光照条件下，研究了光周期对入侵北美东部的棕带臭虫（Halyomorpha halys）（半翅目：臭虫科）完成繁殖滞育的影响。估计至少有 50%的潜在繁殖种群的关键光周期为 13.0-13.5 小时，随着光周期的增加，雌性繁殖的可能性增加，首次产卵的时间更早，繁殖力更高。这些关于该物种对光周期反应的数据与之前的模型预测一致，即光周期和温度对 H. halys 繁殖的双重限制，阻止了在整个美国大陆的任何地方进行滞育的种群每年产生超过两代。然而，H. halys 滞育的兼性性质使得亚种群在某些条件下可能不会进入滞育，这可能允许有更多的年度世代。
