What is "tachina"

Tachina \Tach"i*na\, n.; pl. Tachin[ae]. [NL., fr. Gr. tachino`s, for tachy`s swift.] (Zo["o]l.) Any one of numerous species of Diptera belonging to Tachina and allied genera. Their larv[ae] are external parasites of other insects.

n. (context zoology English) Any of the genus (taxlink Tachina genus) of large tachinid fly, mostly parasitoids on lepidopteran caterpillars.

Tachina is a genus of large flies in the family Tachinidae, most have larvae that are parasitoids of Lepidopteran caterpillars. There are approximately 600 species worldwide.