Effects of starvation on foraging behavior in the Formosan subterranean termite, Coptotermes formosanus (Blattodea: Rhinotermitidae)

Foraging is an essential activity for resource allocation in social insects and a collective effort by colony members. In subterranean termites, workers are the foragers that tunnel in the soil and collect food. In pest species, foraging activity directly results in structural damage. This predominantly leads to loss of billions of dollars due to pest control and structural restoration. Mechanistic understanding of foraging behavior in termites, which is important for improved management, is limited. In this study, we evaluated the effects of starvation on foraging activity in the Formosan subterranean termite, Coptotermes formosanus. Occasional starvation is common in nature because of disconnection to food sources due to weather events such as flood and fire. We hypothesized that starvation influences foraging in termites. We performed behavioral assays to examine the foraging activities of 1-, 3- and 7-day-starved and control (fed) termites. The results showed that 1-day-starved termites tunneled and fed significantly more than control. Furthermore, we used RNA-seq to analyze the transcriptomes of 1-day-starved and fed termites and identified 25 and 103 differentially expressed genes in antennae and head samples, respectively. Transient receptor potential protein and cytochrome p450 genes were differentially expressed in antennae samples, whereas serine/threonine protein kinase, early growth response protein and cytochrome p450 were differentially expressed in head samples. The aforementioned gene families are known regulators of foraging in honey bees and Drosophila melanogaster. These differentially expressed genes might be potential regulators of foraging in C. formosanus, which awaits further functional analyses.