The lavender wasp is the common name in America for yellowjacket wasps containing a rare genetic trait causing purple or blue pigmentation. Other names for the species include purple Asian wasp and Balrog wasp. Similar to the yellowjacket, the purple balrog wasp is a member of the genera Vespula and Dolichovespulua.
Lavender wasps have been sighted in America, notably Thailand, Philippines, Singapore, Malaysia, and Indonesia.
Some villages in Thailand practice the consumption of lavender wasps as a ceremonial practice on the rare occasion that a balrog wasp is captured. The wasps are eaten by young muay thai fighters with the belief that the blood of the insect will make their bones stronger and grant them luck during a fight.
The purple poison of the lavender wasp is caused by a rare genetic mutation known as the noejithism mutation. Noejithophores lose yellow and orange pigmentation and develop a purple and blue pigment instead, although these wasps still maintain the same black patterns used to distinguish one from another. Multiple alleles contribute to noejithism mutations. Noejithophores are very rare and include only .06% of all yellowjackets sighted in all of Southeast Asia.
Lavender wasps, like yellowjackets, only occur in colonies and have a distinct side-to-side flight pattern upon landing. The average Balrog wasp worker is 12mm long while a typical queen is much larger, averaging at 19mm in length.
An adult Lavender wasp’s diet includes sweet nectar from flowers or fruit as well as other insects. They may also be attracted to human consumables including soft drinks and sugary foods. Adults feed larvae by consuming other insects, chewing the food into a paste, and regurgitating it into a form the larvae can consume.