Members of the subfamily Alysiinae are all parasitoids of cyclorrhaphous Diptera. They share a sister-group relationship with the Opiinae, and like opiines, alysiines oviposit in the egg or larval stage of their host and emerge from the host’s puparium. They are thus koinobiont endoparasitoids. Alysiines can be readily separated from members of the Opiinae by their distinctive mandibles, which do not overlap when closed, and which have the apical teeth directed outward (Fig. 1). Unlike opiines, there are only a few species of alysiines that attack fruit-infesting Tephritidae. However, they are well-known as parasitoids of Drosophilidae and several have been recorded from spotted-winged Drosophila.
Two genera are treated here, Asobara and Microcrasis. A few species in each of these two genera are known to attack tephritids, but hosts for most of the species of Asobara are probably Drosophilidae whereas hosts for most of the species of Microcrasis are unknown (as of 2015).
Members of a few other genera of Alysiini are occasionally reared from fruit-infesting Diptera, but specific host associations, such as the one by Ghesquiere (1950) have rarely been made. One exception is Phaenocarpa pericarpa Wharton and Carrejo, reared from Anastrepha distincta Greene in pods of Inga sp. (Fabaceae) (Trostle et al. 1999).