17 
transverse parallel grooves. At the curved lateral regions of the shield 
are found slight depressions, and again one at the posterior end of the 
median line. The shield is further traversed by irregular lines or 
wrinkles, and in addition contains short white interrupted lines and 
spots much the same as those found in the stripes of the body. Dor- 
sally the second and third segments each have a transverse row of four 
piliferous tubercles. The fourth to tenth segments, inclusive, have each 
four piliferous tubercles, slightly larger than those of the second and 
third, and are arranged in the form of a trapezoid, the anterior pair be- 
ing nearest together. On the eleventh segment the four tubercles are 
arranged in the form of a square ) on the twelfth the trapezoid is re- 
versed, the posterior pair of tubercles being nearest together. 
Laterally, the first segmeut is provided with a spiracle about which 
are two piliferous tubercles. Below there are two smaller tubercles 
which are usually contiguous and appear much like one tubercle from 
which two bristles project. The second and third segments each have 
two large piliferous tubercles, two slightly smaller ones and two still 
smaller. The fourth to eleventh segments inclusive each bear three 
tubercles arranged in triangular form about the spiracles with a fourth 
smaller one below them. The twelfth segment usually has two placed 
contiguously, or nearly so. Centrally the tubercles are all small. The 
fourth segment bears six small tubercles arranged so as to form the arc 
of a circle. The fifth segment has two transverse rows of tubercles, 
four in each, the ones in the anterior row being wider apart than those 
in the posterior. The tenth, eleventh, and twelfth segments each bear 
a transverse row of four tubercles. All the tubercles throughout have 
projecting from them a short, stout hair, or bristle. 
The growth of the larvae is somewhat slower during their earlier 
stages than when half grown and approaching maturity. 
AVhen neariug maturity the molts occur at shorter intervals. The 
intervals between molts become longer later in the season or with cold 
and unfavorable weather. Thus in August the first molt occurred on 
the fifth day after hatching, the second on the tenth, the third on the 
fourteenth, and the fourth on pupation, seven days later. September 
25 some eggs began hatching; the first molts occurred on the-seventh 
and eighth days thereafter, the second on the fifteenth and sixteenth 
days 5 at this time the particular worms under observation made their 
escape and the interval of subsequent molts could not be recorded. 
The length of the larval state is longer later in the season. Thus at 
SliL'eveport, Louisiana, Dr. A. R. Booth reports that during August a 
worm matured and was preparing to pupate after having fed 15 days 5 
another after 18 days. At Holly Springs, Mississippi, for the same 
month worms matured within 18 to 20 days after hatching. For Sep- 
tember worms hatched about the first of the month, matured in from 
21 to 26 days, while larva3 hatched September 25 escaped after 18 days 
days and had only just molted the second time. 
23024— No." 21—2 
