Howardula is a genus of nematode that infests the larvae of mushroom-feeding flies, beetles, and other insects.

[1] Howardula husseyi can infest the mushroom phorid Megaselia halterata.

Over the course of the fly host's metamorphosis, the female nematode matures into an adult stage called the motherworm.

After the adult fly emerges from its pupa, the motherworm begins releasing juvenile nematodes directly into the hemocoel, renewing the cycle.

[1] Other insect-infecting nematodes such as Steinernema and Heterorhabiditis are used as biological control agents, as they efficiently kill their insect prey.