This family contains around 150 species of nematodes that parasitise different groups of insects. For example, species of the genus Thripinema infect thrips. Other members of the Allantonematidae have hosts from the insect orders Coleoptera, Diptera or Hemiptera. Unlike the members of other families of entomopathogenic nematodes (e.g. see the Steinernematidae or Heterorhabditidae) the host is not killed, only weakened and/or sterilised. In some hosts, infection rates of 30% or more have been reported (e.g. Yaman et al., 2009).
Fertilised females of Allantonematidae enter the host insect through soft parts like the intersegmental membranes, usually with the help of a stylet. They grow inside the haemocoel of the host, become round and swollen and lay eggs or juveniles. These develop through several immature stages before leaving the host, usually through the intestine. Outside their hosts, they mature and mate but do not feed.
The following genera and species are currently entered in the system: