Biology of a nocturnal bee,Megalopta atra(Hymenoptera: Halictidae; Augochlorini), from the Panamanian highlands

Abstract

Bees of the genus Megalopta have gained attention as a result of their social nesting and nocturnal foraging. Seventeen nests of Meglaopta atra from the highlands of Chiriqui Province, Panama, were collected at the end of the dry season when brood rearing is expected to be at its peak. Most nests contained single females; within multifemale nests only one female possessed enlarged ovarioles, although some non-reproductive individuals were inseminated. In two of these nests reproductive individuals were clearly larger in body size than nestmates, but body size variation and macrocephaly were equivalent to those found in other Neotropical augochlorines. There was no evidence of a nonreproductive worker-like caste and multifemale nests did not appear to be more productive than solitary nests, which may represent pre-reproductive assemblages. Megalopta atra appears to be isolated by altitude from co-geners common in Panama, this is discussed in comparison with temperate halictine bees, in which environmental dines separate solitary from social populations.

Social competition but not subfertility leads to a division of labour in the facultatively social sweat bee Megalopta genalis (Hymenoptera: Halictidae)

“…Megalopta genalis females excavate tunnel nests in dry, rotting sticks (dead branches or lianas) that are usually suspended in vegetation or otherwise raised above the ground, and nests are singly founded (Smith et al 2003;Wcislo et al 2004;Tierney et al 2008a). On BCI, emerging M. genalis adult females can disperse to reproduce solitarily or they can remain in their natal nest and act as workers.…”

Nest structure and notes on the social behavior of Augochlora amphitrite (Schrottky) (Hymenoptera, Halictidae)

“…Although most species nest in the soil, some lineages have shifted to the use of decomposing wood as a nesting substrate. Such behavior has originated repeatedly within the tribe (Engel 2000), and is known in Augochlora, Megalopta, Xenochlora, and some species of Neocorynura (Brosi et al 2006, Wcislo and Gonzalez 2006, Tierney et al 2008a, b, Tierney et al 2012.…”

Photic niche invasions: phylogenetic history of the dim-light foraging augochlorine bees (Halictidae)

“…Megalopta atra is unique in its montane distribution, found only at mid-elevations (approx. 1000 -1500 m) in Costa Rica and Panama [24,27]. Mountain peaks as species isolation mechanisms have been empirically demonstrated [65], and should be more extreme in the tropics [66], owing to a decreased range in temperature tolerance relative to temperate species.…”

“…(a) Specimen collection and study taxa Bees were collected at light traps or from nests (see [23][24][25][26]) at localities given in the electronic supplementary material, table S1. The most abundant genus is Megalopta (approx.…”

“…The most abundant genus is Megalopta (approx. 30 species, including five parasites), which are distributed from Mexico to northern Argentina and southern Brazil, predominantly in lowlands, with one Central American montane species [24,[27][28][29][30][31]. Megaloptidia (three species) occur in the Amazon basin and Guiana Shield [28,32], and Megommation s. str.…”