■ Tachinids of Bertha Armyworm

It is apparent from studies on the parasitoids of bertha armyworm that Athrycia cinerea is by far the most significant tachinid attacking this pest. Next in importance is Panzeria ampelus, but like the rest of the known tachinid parasitoids of bertha armyworm, its parasitism is very low and virtually restricted to outbreak periods when bertha armyworm populations are abnormally high. These less commonly recorded tachinids are presumably facultative parasitoids of bertha armyworm, as a rule preferring other hosts. If the parasitism rates of these tachinids on bertha armyworm could be manipulated, particularly at the beginning or during outbreaks, then these species could potentially offer an additional measure of biological control against this pest.

A useful avenue for further investigation of the tachinids of bertha armyworm is characterization of their larval and pupal stages. The mouth hooks of a third instar tachinid are left behind in the puparium when the adult emerges, and these plus the structure of the puparium can be used for identification purposes. Often the identification is less precise than that based on adult structures (reliable only to genus in many cases), but in situations where pupae die or cannot conveniently be reared, identification of an immature stage might be useful.