Xylocopa pubescens

Xylocopa pubescens is a species of large carpenter bee. Females form nests by excavation with their mandibles, often in dead or soft wood. X. pubescens is commonly found in areas extending from India to Northeast and West Africa. It must reside in these warm climates because it requires a minimum ambient temperature of 18 degrees Celsius in order to forage. A common area of study in X. pubescens is its dominance hierarchy and guarding behavior. Colonies start and end with female takeover, either by daughters of the dominant female or by foreign intruders. There is only one reproductively active female in a colony at a time who suppresses the reproduction of other females in the nest. Males hold individual territories which females enter to mate. When an intruder enters another male's territory, the male responds aggressively. X. pubescens is polylectic, so it forages on many species of plants. It forages on some plants for nectar when preparing bee bread during ontogenesis and forages on others for pollen to feed offspring. Pheromones from Dufour's gland are vital to mark flowers previously visited and also to mark nests so that the foraging bees know where to return. X. pubescens is known to be an effective pollinator, often more effective than honeybees, but it is not commonly used in today's agricultural settings. Xylocopa pubescens is in the order Hymenoptera, which includes bees, wasps, ants, and sawflies, and in the family Apidae, which is a large bee family. Xylocopa pubescens belongs to the Xylocopa ('wood chopper') genus in the subfamily Xylocopinae, a genus composed of over 400 species of large carpenter bees. It is a member of the subgenus Koptortosoma, which is the largest Xylocopa subgenus and is widely distributed with over 200 species. X. pubescens is polyphyletic and comes from a sister lineage of Mesotrichia. In scientific Greek, Xylocopa pubescens literally means 'wood chopper covered with erect hairs'. X. pubescens is a species of large carpenter bee. Females are large and shiny, with black coloration and yellow markings on their heads. Males are smaller than females, distinguished by a narrow head and yellow pubescence (erect hairs) that covers their entire bodies. X. pubescens has been found throughout the Eastern Mediterranean Basin, North Africa and the Middle East. It ranges from Cape Verde to South Asia. It recently expanded its distribution to Spain and Greece in Europe.The species tends to inhabit these relatively warm areas as it requires a minimum temperature of 18 °C in order to forage. Nests can be found in dead and soft wood, as well as the wood of some man-made buildings. X. pubescens makes its nest in dead tree trunks, sticks, canes, branches, or soft wood such as eucalyptus. These nests are sinuous, branched nest typified by short tunnels. Entrance holes are 1.1–1.3 cm diameter; a widened entryway leads into a chamber that is 1.8–1.2 cm. Tunnels 1.4–1.8 cm in diameter start at the chamber, follow grain, and are 5–7 cm long, consisting of few cells each. Females enlarge nests by digging new tunnels when progeny are in the late larval or pupal stages. Progeny often make their own tunnels in the same tunnel complex as the mother, branching off from the common chamber with the mother’s exit hole as the only access to outside. Females can extend tunnels or excavate new nests each nesting cycle. They occasionally widen current tunnels 0.5–1.0 mm each cycle. The excavating of the nests is done with mandibles. Colonies can be founded throughout the breeding season, which takes place from the beginning of March to the beginning of November, depending on ecological conditions. Each colony is founded by a solitary female. The brood is produced continuously as long as space and resources are available. Young males and females emerge from the beginning of May until the end of the breeding season in November. Overlapping generations can be found in nests starting at the beginning of May. All spring nests contain only one bee (either a young female or an old female who has overwintered) until the progeny of the bee enters the pupal stage. After that, between 1–8 adult females may be present one time as new adults remain in the nest for up to 2 weeks. Colony and nesting cycles coincide.