Family Tachinidae - Parasitic Flies

current taxonomy in (1)

Tachinidae Robineau-Desvoidy 1830

Second largest dipteran family (after Tipulidae), with ~1350 spp. in >300 genera of 4 subfamilies in our area(1) and ~8600 spp. in almost 1500 genera total; estmated diversty may be twice as big(2)(3)

* –taxa not yet in the guide; classification adapted from (1)(4)

Family Tachinidae

SUBFAMILY DEXIINAE

SUBFAMILY EXORISTINAE

SUBFAMILY PHASIINAE

SUBFAMILY TACHININAE

Many look similar to muscids and flesh flies. Subscutellum is a useful character:

worldwide and throughout NA

larval hosts: insects from 11 orders and a few other arthropods (myriapods, spiders, scorpions)(2)(7); adults may take nectar

Current knowledge summarized in (2). Most hibernate in the pupal stage.

Larvae are parasitoids of other arthropods. Some tachinids are very host-specific, others use a wide variety of hosts. Some tachinids deposit eggs directly on the host. Upon hatching the larva usually burrows into its host. Full-grown larva leaves the host and pupates. • Tachinids lay eggs in a variety of ways: place a few on host; scatter many in an area frequented by hosts; lay on leaves by host larvae. The eggs have a tough shell and can remain viable for weeks until ingested by host. Some deposit newly hatched larvae on leaves, logs, or soil where larvae search for host. Such larvae have 2 false legs, long cerci, and thick cuticle to prevent desiccation. Once inside the host they turn into legless maggots. Tachinids that parasitize beetles have elaborate abdominal segments that help snatch the host in flight and pierce the cuticle.

Eggs larvae puparium • eggs on hosts

At least 16 species have been introduced as biological controls (Grenier 1988)

(8)