1960] 
MacLeod — Boriomyia 
33 
head withdrawn within the prothorax as far anteriorly as the bases 
of the antennae. 
The body pattern visible to the eye is the result of the interplay 
between three somewhat variable features. The integument is lightly 
pigmented by a mottled pattern of a diffuse, purple color which over- 
lies a much darker reddish-purple color due to the gut contents and 
hemolymph. Between these regions, the rapidly developing fat body 
creates an intricate series of patches which are nearly pure white in 
regions where the cuticle is faintly pigmented and which show as 
darker purple areas where the cuticle is more darkly pigmented. The 
exact pattern which the larva presents depends largely on the extent 
of the development of the fat body which gradually fills most of the 
available space of the hemocoel. One constant feature of this pattern 
is the presence of two white transverse bands across the body on the 
posterior subsegments of the prothorax and mesothorax due to the 
near lack of cuticular pigment in these regions. Ventrally the pal- 
pigers consistently include a small portion of the fat body within 
them which shows through the clear cuticle as a snow-white patch. 
In a dorsal view of a fully mature third instar larva (fig. 4) the fat 
body will be seen to have ramified throughout the body leaving only 
paired lateral “windows”, from the posterior margin of the prothorax 
through the sixth abdominal segment, and the aorta in the dorsal mid- 
line through which the darker color of the hemolymph shows through. 
A typically hemerobiid cocoon is spun by the third instar larva. 
This consists of a loose network of silk strands within which is 
located a more-compact inner cocoon which is, nevertheless, open 
enough to permit easy observation of the final stages of development. 
Pupation, metamorphosis and the eclosion of the adult all occur with- 
out any apparent cessation of development. The pupa is typical of 
that of many hemerobiids studied by the writer and, so far as can 
be ascertained, possesses no prominent features peculiar to Boriomyia. 
Post first instar development may be summarized as follows: 
Measurements 
Length 
mature second instar larva — 
mature third instar larva — 
Maximum width of head capsule 
second instar larva — 
third instar larva — 
Developmental times 
second instar larva — 
3.32 zb 0.43 mm. (N = 5) 
4-53 ± 1-05 mm. (N = 5) 
0.3426 zb 0.0063 mm. (N = 4) 
0.4073 zb 0.0087 mm. (N = 3) 
3.5 zb 0.7 days (N = 20) 
