Robber bees (Lestrimelitta limao) and their host chemical and visual cues in nest defense byTrigona (Tetragonisca) angustula (Apidae: Meliponinae)

Abstract

The nest of the stingless bee,Trigona (Tetragonisca) angustula, is guarded by bees positioned in the nest entrance and others hovering in front of it. Hovering guard bees track returning foragers sideways along the last 10 cm in front of the nest, but intercept and incapacitate nest intruders by clinging with mandibles to wings and legs. When attacked by the cleptobiotic stingless beeLestrimelitta limao, the colony strengthens its aerial defense with hundreds of additional hoverers. To test our hypothesis that this reaction is due to interspecific chemical communication based on kairomone effects, we presented synthetic cephalic volatiles of both species at the nest entrance and counted the number of bees leaving the nest and taking up hovering positions. We conclude that guard bees recognizeL. limao by the major terpenoids of their volatile cephalic secretions, geranial, neral (=citral) and 6-methyl-5-hepten-2-one; other components may fine-tune this recognition. The effect of chemical stimuli is not significantly enhanced by combination with a dummy ofL. limao. Guard bees, we hypothesize, respond to this kairomone by secreting a species specific alarm pheromone; a major component of this pheromone, benzaldehyde, recruits additional bees to defend the nest.

Nota sobre abelhas Lestrimelitta rufipes (Freise) (Hymenoptera, Meliponina), atraídas por armadilhas com iscas odoríferas, na região Sul Fluminense do Estado do Rio de Janeiro

“…Por não possuírem corbículas, as lestrimelitas saqueiam ninhos de outras espécies de abelhas, vivendo à custa do mel, do pólen e da cera, armazenados nessas colmeias. Por esse motivo, elas são consideradas abelhas pilhadoras ou cleptobióticas (Roubik 1989, Wittmann et al 1990). Ao saquear outras colmeias, as operárias liberam substâncias voláteis produzidas por suas glândulas mandibulares.…”

Abelhas-sem-ferrão amazônicas defendem meliponários contra saques de outras abelhas

“…Quando apenas Tetragonisca angustula era tida como uma espécie resistente, a resistência foi explicada com base na simpatria das espécies (T. angustula e L. limao) e, portanto, na longa história evolutiva compartilhada dessas duas espécies (Wittmann et al 1990). No entanto, o presente trabalho e o realizado com M. rufiventris Lepeletier, 1836(Pompeu e Silveira 2005, mostram que a resistência ocorre em diferentes gêneros de Meliponini.…”

The Natural History of Nest Defence in a Stingless Bee, Tetragonisca angustula (Latreille) (Hymenoptera: Apidae), with Two Distinct Types of Entrance Guards

“…Hovering guards attack allospeci ic intruders, particularly those with a volatile odour, such as workers of L. limao which smell strongly of citrus, or which are of a different colour than T. angustula workers (Wittmann et al 1990, Bowden et al 1994. The hovering guards force intruders to the ground by grasping legs and wings with their mandibles (Wittmann 1985, Bowden et al 1994.…”

“…The other type, so far known only in this species, are hovering guards. Most hovering guards ("main group"; see Kärcher & Ratnieks 2009) hover within 20 cm of the entrance (see ig 1 in Wittmann 1985) facing the light path in front of the entrance (Wittmann 1985, Wittmann et al 1990, Kelber & Zeil 1997. A few guards hover 20-50cm from the entrance, to the right or left ("side groups") (Kärcher & Ratnieks 2009).…”