184 Journal New York Entomological Society. t^'o'- ^^• 



the first instar only they are much longer and each one consists of 

 many more joints. The penultimate segment now possesses only the 

 dorsal spines and the basal joint of each of the lateral spines. The 

 mesothoracic dorsal spines are now over 2 mm. in length and g-iointed. 

 The other spines are about the same length and also g-jointed. At 

 the side of the proximal joint of each spine is a short, stout, lateral 

 spine. This spine is longer than the thickness of the large spine while 

 in P. edcntnhis Lee. it is shorter (Figs. 28, 29). This serves as a 

 good separating character from the second stadium to the end of the 

 larval life. Spiracles are wanting. The second stadium occupies on 

 the average, about nine days. 



Third Instar. The Mature Larva. — The second molt occurs eight 

 to ten days after the first. The larva is now in its last stage. This 

 stage lasts from seven to ten days, dependent largely upon the food 

 supply. Length, excluding the caudal setre, 6 mm., caudal setre 4 mm. 

 Antennae are now 4-jointed with a terminal spine. The last segment 

 consists of two closely united pieces, placed side by side (Fig. 26). 

 Ocelli six, placed on a prominent lateral elevation. The larva con- 

 sists of twelve segments. Each segment except the first and the 

 penultimate with the spines arranged as in the preceding instar. The 

 prcthoracic segment now has six jointed spines, two lateral and four 

 dorsal (Fig. 34). The extra two spines develop during the second 

 stadium and appear at the time of the molt. These two extra spines 

 are smaller and fewer jointed (ii-jointed). The mesothoracic spines 

 are i8-jointed and 4 mm. long. It is rather difficult to be certain 

 regarding the number of segments in these long, delicate spines as 

 they break off very easily. The other spines range about the same 

 length with varying number of segments. The penultimate segment 

 has two dorsal spines and only the reduced basal segment of the 

 lateral spines. Spiracles are wanting. 



The mouth parts and legs are practically identical with those of 

 P. edcntnlns. These are described in detail further on. 



Pupation. — When mature the larvae leave the water in search of a 

 place in damp soil to pupate. They begin entering the soil about a 

 week to ten days after the second molt. Here they hollow out a 

 small cavity within which they transform (Fig. 37). The prepupal 

 period lasts about a week to ten days. 



Pupa. — Length 3.5 mm. entirely white (Fig. 38) and remains so 



