50 NEW ZEALAND NEUBOPTERA. 



STENOSMYLUS INCISUS. 



OsmijlusU) incisus, McLachlan, Journ. of Entomology, 

 vol 2, p. 112, pi. 6, fig. 1 (1863). Stenosmylus incisus, 

 McLachlan, Ent. Mo. Mag., vol. 6, p. 195. 



(Plate VIII., fig. 2, 3 larva magnified, 4 pupa magnified.) 



This very beautiful insect appears to be fairly common 

 in the forests of the North Island. In the South Island 

 it has occurred in the Nelson and Otago districts. 



The expansion of the wings is 2£ inches. The fore-wings are very 

 narrow near the base, with the apex much rounded and the termen rather 

 deeply excised. In colour the body is brownish-black ; the wings are 

 tinged with very pale brown, and are clouded with darker brown. There 

 are three irregular blotches on the dorsum, and a somewhat lunate mark 

 near the apex, besides a very large number of more or less distinct smaller 

 markings. The hind-wings are more or less elliptical in shape; their 

 markings closely resemble those of the fore-wings, but are less distinct. 

 These markings vary very much in strength in different individuals. One 

 rather uncommon variety has nearly all the smaller markings absent, and 

 the larger ones are merged almost insensibly into the ground colour of the 

 wing, which is considerably darker than usual. On the other hand, many 

 specimens have the wings almost transparent, and in these the darker 

 markings are proportionally fainter. 



The larva of this insect lives under stones close to the 

 edges of streams, in densely wooded valleys. Although 

 it does not frequent situations which are submerged for 

 long periods, it is only to be found in very wet places. 



The length of this larva when full grown is nearly § inch. Its general 

 colour is black and very shining. The head is round and very horny ; the 

 mandibles and maxillae are closely pressed together, extremely long, and 

 form in conjunction two lance-like organs, which project forwards and 

 upwards. They are considerably more than one-third of the length of the 

 body of the insect. The labial palpi are very long, and consist of six 

 joints. The first is rather long and slender, the second stouter, short, and 

 round, the third very long and slender, and the remaining three much 

 shorter, of equal length and very slender. The legs are short and not very 

 stout. The prothorax is rather narrow, and is longer than the other two 

 segments of the thorax. Each division is furnished with two large 

 metallic dorsal plates. The abdomen gradually tapers towards its ex- 

 tremity, which is furnished with a strong proleg. There are several shining 

 metallic tubercles on each segment of the abdomen. Each tubercle emits 

 three or four long, stout bristles. 



This larva is unquestionably carnivorous, but I have 

 not yet ascertained the precise nature of its food. 

 Numerous small insects and crustaceans are found in 

 the situations frequented by the larva, and it is probable 

 that it preys upon these small creatures. When full 

 grown the larva of this insect constructs a thin, white, 

 silken cocoon, which is usually attached to a small stone 



