Dohrniphora Flies Decapitate Injured Ants

Posted on January 6, 2015

D. longirostrata decapitates an Odontomachus ant

Scientists have discovered that Dohrniphora flies in the tropical forests of Brazil remove the heads of injured trap-jaw ants. The flies have been observed removing the heads from injured ants and taking the heads away. In the above photograph, a D. longirostrata is working to decapitate an Odontomachus ant.

Scientists already knew that some flies of the family Phoridea cause decapitation in ant hosts when they lay eggs in the ant hosts. Larvae then feed inside the ant's head eventually causing it to fall off. However, the behavior of the Dohrniphora flies is something completely different. When the flies come across an injured trap-jaw ant they move in for the kill. The researchers say the flies "industriously sever the gut, nerve cord, and other connections of the head to the rest of the body" using their sharp mouthparts. The researchers say this process takes a few minutes. The flies then use their front legs to grab onto the ant's head and pull on it until it pops off. The flies then drag the ant head along the forest floor until they find a secluded spot. Then they flies either feed on the contents inside the head or lay eggs near it.

Here is a video of a fly removing an ant's head. The ant on the left is that one that loses its head. Take a look:

The behavior was discovered by scientists from the Natural History Museum of Los Angeles County including lead author Dr. Brian V. Brown and Giar-Ann Kung. A research paper on the ant decapitation process can be found here.

Photo: Wendy Porras