Foraging signals in the Neotropical termite Nasutitermes corniger: The role of castes and intercolonial perception

Abstract

Social insects are known to have a complex and elaborate communication system. In termites, communication through chemical signals is paramount, as the soldiers and workers of the majority of species are blind and have cryptic habits. Despite this, knowledge about the role of foraging signals in termites is still scarce, especially in phylogenetically derived species. Here, we aimed to analyze the role of foraging signals in Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae), including the effect of various glands and/or caste origins of foraging signals, the response of groups with various caste compositions, and the intercolonial perception of these signals. Specifically, we tested the following hypotheses: (i) rectal fluid and sternal gland extracts have diverse roles in perception, orientation, and acceptance by groups of N. corniger with distinct caste compositions; (ii) the behavior of N. corniger exposed to intercolonial foraging signals is not altered compared with intracolonial signals; and (iii) intercolonial foraging signals attract N. corniger. To do so, trailing behavior and attraction behavior bioassays were carried out in the laboratory. The sternal gland extract triggered the greatest trailing behavior among the foraging signals. Furthermore, the rectal fluid extract seems to elicit trail-following behavior in N. corniger, whereas the sternal gland extract acts as a recruitment signal. Finally, the behavior and attractiveness of the intercolonial foraging signals were not different from that of the intracolonial signals. The results found in the present study increase the understanding of foraging chemical communication in Termitoidae and reveal the role of intercolonial signals in the attractiveness of groups of N. corniger.