tachinids

Tachinids are a large and diverse family of flies in the order Diptera. They are primarily parasitoids, with larvae that develop inside arthropod hosts, ultimately killing them. Hosts span a broad range of insects, including Lepidoptera, Coleoptera, Hymenoptera, and Hemiptera, with caterpillars and other larval stages being especially common targets. Adults typically feed on nectar and pollen and are often found on flowers.

There are about 11,000 described tachinid species worldwide, organized into several subfamilies such as Exoristinae, Tachininae, Phasiinae, and Dexiinae. Tachinids exhibit varied life histories: most are endoparasitoids of host larvae, while some are ectoparasitoids. A number of species are larviparous and give birth to actively searching larvae rather than laying eggs. Development occurs inside the host, which usually dies as the tachinid larva matures; the final pupation stage typically occurs outside the host in soil, leaf litter, or on plant surfaces before adults emerge.

Tachinids are important natural enemies of pest insects and have been used in classical and augmentative biological control programs against outbreaks of pest moths, beetles, and other insects. Their effectiveness and ecological impacts vary among species and sites, and introductions are carefully evaluated.

They occur worldwide, from deserts to forests, and display a range of body shapes and bristly appearances characteristic of many tachinids. Identification often relies on subtle morphological features and, in some groups, examination of male genitalia, requiring specialist taxonomic keys.