Ampulex dementor is a species of cockroach wasp native to Thailand, described in 2014 by Michael Ohl of the Museum für Naturkunde in Berlin, Germany. The species name was selected by visitors to the museum, in efforts to connect members of the public to issues of taxonomy and the description of biodiversity.
A. dementor is colored in red and black. Its mandibles and most of its clypeus, prothorax, mesothorax, and posterolateral areas are all light red, while its abdomen and much of its head is black. Its wings are slightly yellow. It has long, slender legs, and a tubular petiole, as long as the tergum. Of about 170 species in the family Ampulicidae, Ampulex dementor is the largest. The length of females length varies between 9.6 and 10.9 mm; the length of males is unknown.
The wasp has an unusual behavior towards cockroaches. As it stings its prey, it releases a toxin into the victim's neural nodes. This toxin blocks the cockroach's octopamine receptors, leaving the cockroach alive, but unable to direct its movements. Its muscle functions still active, the cockroach then "runs into" the wasp's nest, allowing for its easier capture by the wasp.
At the time of the wasp's description, visitors to the Museum für Naturkunde (in which the species was described) were asked through pamphlet distribution to choose between four names, of which the third was chosen:
- Ampulex bicolor (the Latin word means "two colors", from bis = twice) due to its very distinctive colours, black and red
- Ampulex mon, an allusion to its origin, Thailand, and one of the earliest "ethnic groups" to live there
- Ampulex dementor, referring to its behavioral resemblance with the Dementors, fictional creatures from the Harry Potter Books franchise, who suck their prey's soul, leaving it an empty body with neither thoughts nor emotions, in a way like the wasp
- Ampulex plagiator, because the species is an ant mimic, a species which "copies" the ant in many ways such as its way of moving and general appearance, making it a plagiarist of said ant
- The emerald cockroach wasp, a bright green metallic wasp with very similar behavior.
- Ohl, Michael; Lohrmann, Volker; Breitkreuz, Laura; Kirschey, Lukas; Krause, Stefanie (2014). "The Soul-Sucking Wasp by Popular Acclaim – Museum Visitor Participation in Biodiversity Discovery and Taxonomy". PLoS ONE. 9 (4): e95068. doi:10.1371/journal.pone.0095068. PMC 3995701. PMID 24755672.
- Izadi, Elahe. "Say hello to the dementor wasp. It turns cockroaches into zombies". Washington Post. Retrieved 28 May 2015.