io2 NEW ZEALAND ENTOMOLOGY. 



Family Sialid^e. 

 C/iauliodes diversus (Plate XIV., fig. I, ia larva, lb pupa). 



During still warm weather, from December till March, 

 this large insect is frequently observed flying lazily over 

 water at dusk, when it may be readily captured with the 

 ordinary net. Its larva is aquatic, living under stones in 

 running streams, where it devours large quantities of 

 Ephemerae and other insect larvae, which are always abun- 

 dant in those situations. It is very ferocious and will bite 

 violently when disturbed, being furnished with a pair of 

 powerful mandibles. The curious filaments on each side 

 are gills, and it will be noticed that they are situated 

 exactly where the spiracles of the perfect insect afterwards 

 appear (see Fig. ia). 



This larva probably lives over a year, its growth pro- 

 ceeding very slowly, but mature specimens are not in- 

 frequently met with quite as large as the illustration. When 

 full-grown it leaves the water and forms an oval cell in the 

 mud, usually under a large stone ; its gills then gradually 

 shrivel up, and in ten days or a fortnight it is transformed 

 into the curious pupa, shown at Fig. lb, from which the 

 perfect insect proceeds in about six weeks' time. The sexes 

 of this species may be readily distinguished by their size, the 

 male being considerably smaller than the female (Fig. i), 

 and possessing longer antennae. 



