Miltogramma mestor (?) (Plate [VII], fig. 5).
A conspicuous species, found occasionally on forest-clad hills round Wellington. The life-history is at present unknown, but its larva is very possibly parasitic in some large Lepidoptera.
Family Muscidæ.
Nemorea nyctemerianus (Plate [VII]., fig. 6).
This little fly is seldom met with in the perfect state. Its larva is parasitic on the caterpillar of Nyctemera annulata[[13]], the eggs being deposited on the moth larva at an early age. The caterpillar grows and eats in the ordinary way, until it has assumed the chrysalis state, when the maggot eats its way out and changes into a dark-brown pupa. In this condition the parasite is protected by the web which was previously constructed by the unfortunate caterpillar for its own use. The perfect fly appears in about six weeks' time, its great agility and large white scales rendering it very conspicuous.
Family Muscidæ.
Eurigaster marginatus (Plate [VII]., fig. 7).
Another parasitic species, its larva inhabiting the caterpillars of various noctuæ which it destroys just before they change into the chrysalis state. The pupa of the parasite lies in a small oval cell constructed in the earth by its larva. A variable number of these maggots are found associated in one host, the smaller caterpillars only harbouring a single individual, while a large larva will frequently contain three or four. This species has been bred from the following Lepidoptera: Mamestra composita, M. ustistriga and M. mutans. It also occurs in the curious Œceticus omnivorus, being found in the cocoons of that moth in numbers varying from two to eleven, or even more, and it is especially interesting, as it is in turn destroyed by a small species of Pteromalus already noticed among the Hymenoptera (page [37]). The perfect insect occurs occasionally on flowers throughout the summer.
Family Muscidæ.
Calliphora quadrimaculata (Plate [VII]., fig. 9).