Alates of the termite Reticulitermes flaviceps feed independently during their 5-month residency in the natal colony

Abstract

Reticulitermes flaviceps is an invasive subterranean termite in China. The alates of this species stay in their natal colony for about 5 months before dispersal flight. Due to lack of nutrition information of the alates from appearance to swarming, the feeding and trophallactic behaviour of this species were measured using neutral red and rubidium (Rb) tracers. Groups of alates, workers (over 5th-instar), nymphs (6–8th-instar), or soldiers were separately placed into a single petri dish with neutral red liquid stained filter paper for alimentary tract observation. With the exception of soldiers, red-dyed food was all observed in the alimentary tracts of workers, alates, and nymphs, suggesting that workers, alates, and nymphs all feed themselves in the colony. In the rubidium feeding study, over 5-instar workers, alates and soldiers were fed directly on filter papers treated with different concentrations of Rb for 3 days. Workers and alates received the most Rb at the end of the feeding test, suggesting that workers and alates are the feeding castes in R. flaviceps. Soldiers did not feed Rb-treated filter paper, indicating that they do not feed directly on wood. In the trophallactic study, both workers and alates acted as donors and recipients when paired with other workers and alates, and as donors for soldiers. Workers as donors can transfer food to both workers and soldiers with 1.02% and 0.5% transfer efficiencies, respectively, but rarely provide food for alates. Alates as donors can transfer food to other alates, with a transfer efficiency of 1.05%, but rarely provide food for workers and soldiers. These results suggest that during the 5–6 month stay in the natal colony, alates of R. flaviceps feed independently of other castes.