Fighting ability and the toxicity of raiding pheromone in an obligate kleptoparasite, the stingless bee Lestrimelitta niitkib

Abstract The evolution of obligate kleptoparasitism, the theft food, has led to remarkable innovations, including physical weapons and chemical signals that can evolve into weapons. Stingless bees in genus Lestrimelitta are excellent examples this phenomenon because they kleptoparasites no longer collect floral resources instead steal brood from other bees. Their ability raid successfully is thus essential their fitness even when fight species physically bigger, have larger defense forces, or both. We conducted morphometric analyses, quantified niitkib mandibular gland pheromone (MGP) components, carried out individual fighting trials between L. stingless bee Scaptotrigona mexicana , a common victim species, shed light on detailed reasons for success at robbing. Measurements showed mandibles thicker exoskeleton cuticles overall greater width, particularly medial proximal sections, than S . which quite similar body size. In all fights, bit victims released MGP, as it does during raids. exhibited significantly increased uncoordinated behaviors partial complete paralysis. analyzed major components consisted large quantities geranial (mean 253 μg) neral (48 per bee. Microinjections 1 equivalent (BE) natural synthetic MGP ≥ 0.1 BE deleterious paralysis compared control injections. suggest used raiding an unexpected outcome, semiochemical evolving additional function toxin, contribute rob its victims. Significance statement Kleptoparasites, organisms food resources, employ multiple tools survive. kleptoparasitism requires balance honesty coercion interspecific communication. Lestrimellita consists group kleptoparasitic colonies therefore depend upon winning these However, why succeed remains not fully understood. studied differences morphology victims, pheromones release raids, ran identify successful. beginning concert with pheromone’s toxicity, been combined improve ’s rob.