Data from: Evolution of critical day length for diapause induction enables range expansion of Diorhabda carinulata, a biological control agent against tamarisk (Tamarix spp.)

In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on post release evolution of beneficial life history traits. In this study we measure evolution of critical day length for diapause induction, (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America seven years after introduction and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control.

在经典杂草生物防治实践中，研究人员通常从目标杂草原生分布区的一处或少数几处采样点采集少量节肢动物种群，将其引入该杂草已发生入侵的区域——此类入侵区域往往覆盖广阔的地理范围——以抑制杂草种群扩张。在新的入侵区域中，生态错配现象极易出现，而该生防因子的防控成功与否，可能取决于其释放后有益生活史性状的演化。本研究针对一种从中国引入北美、用于防治外来灌木柽柳属（Tamarix spp.）植物的甲虫（Diorhabda carinulata），测定了其滞育诱导临界光周期——即种群中50%个体进入滞育时的光周期——的演化情况。研究于该甲虫引入北美七年后，从四处野外采样点采集其种群，结果显示其滞育诱导临界光周期已出现下降，并沿纬度梯度形成了渐变群；在其中一处采样点，临界光周期的缩短与该甲虫生殖活动延长16天显著相关，使得甲虫的生活史与柽柳的物候匹配度进一步提升。本研究结果表明，该甲虫在柽柳属植物防治中的防控效能得到增强，适用范围也日益扩大。