198 Life History of Wireiuorms 



General Description of the larva in Final Instar. 



Length 22-26 mm.; breadth 1-75-2-0 mm. 



Apart from the head and 9th abdominal segment nearly cylindrical; 

 yellow, usually rather pale. 



Head quadrangular, shghtly broader than long, flattened above and 

 beneath; somewhat darker in colour than the remaining segments. 

 Wider behind than in front, bearing a long seta near each of the four 

 angles, besides several shorter ones situated chiefly anteriorly; punctures 

 sparse and irregular. 



Upper surface with an elongate-oval plate (the cephahc plate), which 

 is expanded anteriorly over the base of each mandible. Anterior margin 

 of the plate, over the entrance to the mouth, with a strongly chitinised 

 brown process, which divides into three sharply pronged denticles, the 

 middle one being the longest. Anterior angles of the head sUghtly 

 rounded. 



Antennae situated close to the base of the mandibles, short, consisting 

 of two segments and two processes borne separately at the apex of the 

 2nd segment. Ventral process shorter, conical and nearly colourless; 

 dorsal process darker and more strongly chitinised, linear and about 

 equal in length to the preceding segment. Probably the latter should 

 be regarded as the 3rd segment. 



Eye spot dark brown or black, situated laterally, a httle below the 

 base of the antenna. 



Mandibles rather small, stout, yellowish brown, with sharply pointed, 

 pitchy black apices ; each bearing two denticles on the inner margin and 

 a brush-hke process, the penicillus, at the base. 



Ventral surface of the head with a pair of somewhat oblique furrows, 

 brown, nearly straight and reaching from the base of the mandibles to 

 points beyond the base of the hypostome, also with two ridges of darker 

 brown chitin, somewhat bowed, situated in the cavity between the epi- 

 cranial plates (genae) and the maxillae and nearly reaching the posterior 

 apices of the cardines. 



Maxillae (Fig. 1) each with a very short cardo, articulating with the 

 tentorium at its second branch. Stipites somewhat rounded on their 

 outer margins and straight within. Palps yellowish-brown, composed 

 of four segments and borne on white membranous palpigers at the apices 

 of the maxillae. Galeae composed of two segments, with a small thimble- 

 shaped process at the apex. Laciniae small, triangular, sharply pointed 

 and densely margined with wavy hairs on their inner margins. Terminal 



