It’s the Gadfly Season!

It’s been a miserable time for elephants and very busy time for our vet, Dr Aon, who has been treating large numbers of gadfly infestations in the region. These blood-sucking insects are particularly prevalent during the rainy season in Thailand, where there are called by various names – Duang, or Tor Lae or Maleang wan pa. According to experienced mahouts and owners, the flies lay eggs under the skin of the elephants. When the eggs hatch they produce larvae which, once mature, push to the surface of the skin and eventually emerge through it, often causing nasty sores where they break through. The emerging larvae will normally fall to the ground where they pupate to become adult gadflies.

For the elephants, this isn’t a particularly pleasant experience. The larvae create soybean-sized lumps under the elephants’ skin, particularly around their sides, hips and bellies, which then irritate the skin causing the elephants to rub against objects such as tree bark to alleviate their discomfort. This in turn often creates small wounds on their skin, but in the process allows the larvae to escape. On closer inspection inside the lumps, the larvae can be seen, usually white in colour with a black mouth and black tail.

During her observations of these gadflies Dr Aon has concluded that there is more than one type of insect feeding on the blood of elephants, and they are not easily identifiable. She has been in contact with two leading entomologists to confirm the identity of these flies, and is also studying their life-cycle by raising larvae to adults in the laboratory. Perhaps Dr Aon has discovered a new species of blood-sucking insect. Watch this space…

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