UC San Diego

Multimodal communication plays an important role in pollination biology. Bees have evolved multimodal communication to recruit nestmates to rewarding food sources. Highly social bees can use visual and chemical information to recruit nestmates to rich food sources. However, no studies have determined if this information is redundant or has an additive effect such that multimodal information is more attractive than either modality presented by itself to free-flying bees. We tested the effect of two modalities, forager-deposited odor marks and the visual presence of foragers, on the orientation of stingless bee (Scaptotrigona mexicana) recruits. Our results show that odor marks alone were significantly more attractive than multimodal information, and that multimodal information was significantly more attractive than visual forager presence alone. Given the high olfactory sensitivity and limited visual acuity of insects, odor marks likely attracted recruits over a greater distance than the visual presence of nestmates. Thus, multimodal information in S. mexicana is redundant, not additive, in terms of orientation to food sources. © 2011 International Union for the Study of Social Insects (IUSSI).