Spring warming increases the abundance of an invasive specialist insect: links to phenology and life history

Under global warming, shifts in phenological synchrony between insects and host plants (i.e., changes in the relative timing of the interaction) may reduce resource availability to specialist insects. Some specialists, however, can flexibly track the shifts in host-plant phenology, allowing them to obtain sufficient resources and therefore to benefit from rising temperatures. Here, we investigated the effects of experimental warming on the life history of an invasive, specialist lace bug (Corythucha ciliata) and on the leaf expansion of its host plant (Platanus × acerifolia) in two spring seasons under field conditions in Shanghai, China. We found that a 2 °C increase in mean air temperature advanced the timing of the expansion of host leaves and of the activities of overwintering adult insects in both years but did not disrupt their synchrony. Warming also directly increased the reproduction of overwintering adults and enhanced the development and survival of their offspring. These results indicate that C. ciliata can well track the earlier emergence of available resources in response to springtime warming. Such plasticity, combined with the direct effects of rising temperatures, may increase the insect’s population size and outbreak potential in eastern China under climate warming.