![]() In Puerto Rico it was noted that compared to European species, the Africanised bees groomed for longer periods - often more effectively - biting and damaging Varroa mites. Killer bees, on the other hand, seem to be more resistant against the factors causing CCD. ![]() Studies have shown that pesticide residues can cause navigational failure, with the bees getting lost and unable to find their way home.Īnother suggested theory of CCD is infestations of Varroa mites, which weaken bees by feeding on their bodies. CCD causes the majority of worker bees to permanently leave their home - leaving the queen, the young and a few nurse bees. Their decline is attributed to factors including pests, pesticides, disease, climate change and habitat destruction.Ĭolony collapse disorder (CCD) is a symptom of this decline. The rate of loss now appears to be reducing, however. Western honeybee numbers have been in decline, especially in the United States where beekeepers reported losses of up to 44% from 2015 to 2016. The bees seem to occasionally mistake neighbours for foes, resulting in attacks on humans, livestock and other animals. They don't attack for the sake of it, only stinging in defence when they believe their colony is at risk.īut they are also acutely sensitive to vibrations. The insects are alleged to have continued their assault when their targets came up for air. Human victims have reported taking refuge underwater to avoid the stings - but the bees are willing to wait. As Africanised bees attack in numbers far exceeding that figure, their nickname comes as no surprise. It is estimated that around 1,000 stings could kill an adult human. With each sting, a pheromone is released, signalling for more bees from the colony to join in the onslaught. There are even reports of swarms of 300,000 to 800,000. When an ordinary European honeybee colony is threatened, around 10% of the bees will venture out to protect the colony's home.īy comparison, killer bees often all but empty their nest. The major difference lies in their nest defence. They are in fact smaller than other honeybees, have shorter wings and carry less venom. Strength in numbersĭespite their name, a single killer bee is no deadlier than any other honeybee subspecies. But if winters become milder, they may be able to continue their expansion northwards. These bees were bred to cope with warm climates, so their invasion is limited by cooler temperatures further north. They were recorded as having reached Texas in 1990 and California in 1994. ![]() The subspecies began spreading northwards from Brazil, through South and Central America and into the United States. They will settle into both natural nest sites and man-made structures. Hardy and adaptable, these bees aren't fussy when choosing a new home. They established new colonies in the area and also invaded local hives. In 1957 around 20 colonies of the new Africanised bees escaped captivity in Brazil. Coordinated defensive manoeuvres enable African bees to better fend off these attacks. However, the new hybrid bees also took on a less desirable trait from their African relations: their aggression.Īfrican honeybees are much more hostile than European varieties, as their natural environment has far more predators looking to destroy hives for honey. The ambitious scientist aimed to isolate traits of each species and breed them into a new subspecies, combining the European bees' greater honey yields with the African honeybees' adaptation to warmer climates. scutellata) in an effort to improve honey production in Brazil. He chose a selection of European honeybees and the African honeybee ( A. In 1956, Brazilian geneticist Dr Warwick E Kerr began to interbreed subspecies of the western honeybee. Known only in North, Central and South America, Africanised honeybees ( Apis mellifera scutellata Lepeletier) are a human-bred subspecies, first bred by scientists in Brazil to be a new honey-producing champion for warmer climates.įamily-oriented and nest-proud, these bees will aggressively defend their hive, and they have a tendency to go all out when responding to a threat. ![]() Their demeanour has earned them the terrifying nickname of 'killer bees', but relatively few deaths are caused in proportion to the number of colonies. ![]()
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