32 
Psyche 
[March - June 
faintly visible between anterior prothorax and eighth abdominal seg- 
ment, toward end of stadium becoming outlined by small isolated 
patches of developing fat body on either side of aorta. Fat body 
particularly well-developed in posterior subsegments of pro- and 
mesothorax. 
Duration of first larval stadium — 3.4 zb 0.7 days (N = 33) 
Length of unfed first instar larva 
(measured from clypeal margin 
of head capsule to posterior 
margin of dorsal sclerite of tenth 
abdominal segment) — 1.57 zb 0.12 mm. (N = 6) 
Maximum width of head capsule 
(measured across ocular 
areas) — 0.3018 zb 0.0009 mm. (N = 7) 
Subsequent development of B. fidelis — The head capsules of the 
second and third instar larvae (fig. 2) are quite similar to each other 
and differ from that of the first instar larva principally in being 
slightly wider in proportion to their lengths, which, combined with a 
lack of the curvature of the lateral margins of the head present in the 
first instar larva, gives the dorsal aspect of the head capsule a distinct- 
ly more quadrate appearance. In addition, the formerly fuscous regions 
of the clypeal area dorsally and the mental region of the labium ven- 
trally of the first instar larva are pale in the subsequent larval instars 
so that only the frontal and parietal areas are darkened in these stages. 
The labial palpi are somewhat less inflated in appearance in the sec- 
ond and third instar larvae although they remain stouter than is usual 
in this family and reach well beyond the tips of the extended jaws. 
The pretarsi of all legs of the second and third instar larvae lack 
the empodium present in the first instar larva, its place being taken 
by a delicate, fan-like arolium, arising from the dorsal surface of the 
pretarsus. Posteriorly, the tergal area of the nineth abdominal seg- 
ment is no longer covered by a distinct sclerite in the second and third 
instar larva. 
The body form of the second and particularly the third instar larva 
(fig. 4) becomes progressively swollen and grub-like with the develop- 
ment of a complex series of projecting lobes on the original segments 
of the body. The anterior subsegment of the prothorax remains short 
and collar-like and the head capsule becomes increasingly retracted 
within this portion of the body, so that although the head can be ex- 
tended, the usual condition in which to find a living larva is with the 
