4 10 Journal of A gricultural Research v 0 i. xxi. No. 6 
When hatched the larva is very slender and gradually tapers toward the 
posterior extremity. At this time the head (PI. 75, D) is considerably 
larger than the individual body segments. Just before the first molt is 
cast (PI. 75, E) the head is much narrower than any of the first 8 body 
segments. The head is convex anteriorly and bears 7 pairs of rather 
long setae and a pair of fleshy cylindrical tubercles which apparently are 
antennae. The mandibles of this stage (PI. 76, A) appear to be very 
highly chitinized, very slender and pointed. The body consists of the 
usual 13 segments bearing 5 pairs of spiracles, a pair on each of the last 
2 thoracic and first 3 abdominal segments. There are 2 lateral rows and 
2 subdorsal rows of long setae, 1 seta to each row to each body segment, 
and 2 subventral rows of long setae on the thoracic segments only; in 
addition, around each segment there are 2 or more irregular rows of 
minute setae. 
Second instar (PI. 75, F).—Color as in previous instar. Average 
length of three larvae 1.1645 mni - and average greatest width 0.3473 
mm. In this instar the larva is pointed at each extremity although 
very much more pointed posteriorly. The head is convex anteriorly 
and bears 5 pairs of setae; antennae as in previous instar. The mandibles 
(PI. 76, B) have changed shape entirely; they are very broad at the base 
and much less heavily chitinized than in the previous instar. There are 
9 pairs of spiracles present, 1 pair to each of the last 2 thoracic and first 
7 abdominal segments. The short, minute setae present in the first 
instar are not present in this or any of the succeeding instars, and the 
long setae are shorter but are arranged on the body as in the previous 
instar. 
Third instar (PI. 75, G).—Color same as in previous instar; average 
length of three larvae 1.3533 mm - and average greatest width 0.4083 
mm. Shape is much the same as in the previous instar. Head bears 8 
pairs of setae, which are longer than in the previous instar; antennae same; 
mandibles (PI. 76, C) much longer and more slender and about as heavily 
chitinized as in the previous instar. The setae of the body are much 
more numerous and are longer than in the previous instar. The first 
segment bears a partial double row of setae around it; the other segments 
bear an irregular single row of setae of unequal length around them. 
Fourth instar (PI. 75, H).—Color and shape as in previous in¬ 
star; average length of three larvae 2.1233 mm. and average greatest 
width 0.5833 mm. Head as in previous instar except that setae have 
become much longer and more numerous; antennae same; mandibles (PI. 
76, D) same general shape as in previous instar, but larger. The setae 
of the body are more numerous and are longer than in the previous instar, 
There are three incomplete, irregular rows of setae around the first thoracic 
segment; two rather complete, irregular rows around the second; an 
irregular single row around the last thoracic and all the abdominal seg- 
