Apis mellifera scutellata

The East African lowland honey bee (Apis mellifera scutellata) is a subspecies of the western honey bee. It is native to central, southern and eastern Africa, though at the southern extreme it is replaced by the Cape honey bee (Apis mellifera capensis). This subspecies has been determined to constitute one part of the ancestry of the Africanized bees (also known as 'killer bees') spreading through America. The introduction of the Cape honey bee into northern South Africa poses a threat to East African lowland honey bees. If a female worker from a Cape honey bee colony enters an East African lowland honey bee nest, she is not attacked, partly due to her resemblance to the East African lowland honey bee queen. As she is capable of parthenogenetic reproduction, she may begin laying eggs which hatch as 'clones' of herself, which will also lay eggs, causing the parasitic A. m. capensis workers to increase in number. The death of the host colony results from the dwindling numbers of A. m. scutellata workers that perform foraging duties (A. m. capensis workers are greatly under-represented in the foraging force), the death of the queen, and, before queen death, competition for egg laying between A. m. capensis workers and the queen. When the colony dies, the capensis females will seek out a new host colony. A single East African lowland bee sting is no more venomous than a single European bee sting, though East African lowland honey bees respond more quickly when disturbed than do European honey bees. They send out three to four times as many workers in response to a threat. They will also pursue an intruder for a greater distance from the hive. Although people have died as a result of 100-300 stings, it has been estimated that the average lethal dose for an adult is 500-1,100 bee stings. In terms of industrial honey production, the African bee produces far less honey than its European counterpart, whilst producing more swarms and absconding (abandoning its nest). For this reason, African honey bees are less desirable than European honey bees, except where the proclivity of African bees give beekeepers no other option due to the Africans' tendency to invade and take over European nests. The appearance of the East African lowland honey bee is very similar to the European bee. However, the East African lowland honey bee is slightly smaller. The average body length of a worker is 19 mm. Its upper body is covered in fuzz, and its abdomen is striped with black. The native habitat of Apis mellifera scutellata includes the southern and eastern regions of Africa. The species was first imported across the Atlantic Ocean to Brazil before it spread to Central America, South America, and southern areas of the United States. The Africanized honey bee thrives in tropical areas and is not well adapted for cold areas that receive heavy rainfall. Honey bees are challenged to balance energy consumption and replenishment in their pursuit of nectar. High thoracic temperatures required for foraging flight pose a thermoregulatory imbalance that honey bees attempt to alleviate by targeting particular viscosities and temperatures of nectar resources. In lower environmental temperatures where energy loss is more pronounced, it has been shown through Apis mellifera scutellata that honey bees seek warmer, less-concentrated and less-viscous nectar, an energetically favorable behavior. Nectar that is highly concentrated in sugar is more viscous and therefore reduces the speed of consumption and the size of honey bee crop loads. In cooler ambient temperatures, harvesting small, concentrated quantities of nectar does not allow honey bees to maintain the metabolism necessary for foraging flight. Harvesting warmer, less-viscous nectar is advantageous because of the energy gained by heat. Honey bees are able to stabilize their body temperature and make up for the energy lost by flying. In A. mellifera scutellata, it was found that crop loads were largely contained in the abdomen, though it remains unclear whether this balances out the aforementioned energy loss from the thorax during flight. It appears that the cost of harvesting less-viscous nectar is that it is also less concentrated in sugar and would be an energetic loss for the honey bees. However, this is not the case; the speed of harvesting nectar with less viscosity increases the quantity harvested at a given time. The relative advantage is so great that it is still more energetically favorable for a honey bee to collect warm nectar, even at low sugar concentrations (10%.) Honey bees are energetically rewarded by harvesting nectar that is warmer than ambient temperatures because they make up for energy loss during foraging and obtain more nectar more easily.