A mixed colony of Scaptotrigona depilis and Nannotrigona testaceicornis (Hymenoptera, Apidae, Meliponina)

Abstract

AbstrACt. We describe a case of a spontaneously established mixed colony of two species of stingless bees. The host colony of Scaptotrigona depilis, an aggressive bee that forms large colonies, was invaded by workers of Nannotrigona testaceicornis, a smaller bee that forms small colonies. The host colony and the invading species colony were maintained in next boxes about 1.5 m apart. The N. testaceicornis colony had been recently divided. Observations were made daily for 10 min, and every two weeks the colony was opened for observations within the nest. Initially the host colony bees repulsed the invading species, but as their numbers built up, they were no longer able to defend the entrance. An estimated 60-90 N. testaceicornis workers lived integrated into the colony of S. depilis for 58 days. During this period, they reconstructed and maintained the entrance tube, changing it to an entrance typical of N. testaceicornis. They also collected food and building material for the host colony. Nannotrigona testaceicornis tolerated transit of S. depilis through the entrance, but did not allow the host species to remain within the tube, though the attacks never resulted in bee mortality. Aggression was limited to biting the wings; when the bees fell to the ground they immediately separated and flew back. There have been very few reports of spontaneously occurring mixed stingless bee colonies. It is difficult to determine what caused the association that we found; probably workers of N. testaceicornis got lost when we split their colony, and then they invaded the colony of S. depilis.

Recognition and Defensive Behavior of Nannotrigona testaceicornis Workers (Lepeletier, 1836) (Hymenoptera, Apidae) in Intra and Inter-colonial Bioassays

“…A study demonstrated the occurrence of aggressive defensive behaviors during the attempt of intraspecifics to invade a colony, which led to the death of some workers (Castro et al, 2009). Another record refers to the occurrence of aggressive behavior between interspecifics, such as bites on wings, during the invasion of a S. depilis colony by N. testaceicornis workers (Menezes et al, 2009).…”

“…Castro et al (2009) described the invasion of an established colony by a swarm of the same species, in which there was an impediment to passage through the tube and fights involving the death of some individuals. Menezes et al (2009) reported the invasion of a colony of Scaptotrigona depilis by N. testaceicornis, with the coexistence of both in the same colony. During the process, the authors observed the construction of a specific tube of the intruder species, in addition to aggressive interaction, such as a bite.…”

Inter-colony fights in Tetragonula stingless bees result in temporary mixed-species worker cohorts

“…Although mixed species colonies of stingless bees have been reported, they are rare (Grüter 2020). In one case, Nannotrigona testaceicornis invaded a recently split colony of the larger and more aggressive Scaptotrigona depilis from a nest box maintained 1.5 m away, and the two species co-existed for 58 days (Menezes et al 2009). Also, a naturally occurring mixed colony of Melipona flavipennis and M. fasciata was discovered in a tree cavity (Roubik 1981).…”

Mixed colonies of two species of congeneric stingless bees (Hymenoptera: Apinae, Meliponini) display environmentally‐acquired and endogenously‐produced recognition signals

“…Melipona marginata and Scaptotrigona postica ; Plebeia mosquito and Nannotrigona testaceicornis ). Further investigations emphasize the importance of species with more phylogenetic proximity to the success of mixed colonies (Oliveira & Imperatriz‐Fonseca, 1973; Roubik, 1981; Pianaro et al , 2007; Menezes et al , 2009).…”