494 
Journal of Agricultural Research 
Vol. VII, No. « 
of the egg. Exclusive of this appendage, the egg is about 0.55 mm. in 
length by about a fourth as thick in the middle. It is yellowish white 
and without sculpture. Within two days after oviposition the embryo 
can be seen to have drawn away from the poles, 
and in some the cephalic constriction can be seen. 
Incubation period. —In 1914 the eggs began 
to hatch on the sixth day after deposition, and by 
the eighth day all had hatched. In 1915 hatching 
commenced on the seventh day and continued until 
the tenth day. 
LARVA 
Number and description op instars. —The 
Pig. 2.—s yntomaspis dmpa - newly hatched larva (fig. 3) is about 0.4 mm. in 
nifild^^origSln^ ma8: * en gtli by about a fourth as thick at the thickest 
point, which is at the junction of the thoracic 
and abdominal segments. From this point it tapers in both directions, 
but is much smaller at the caudal end. The body, including the head, 
consists of 14 segments; the 3 thoracic segments are about equal in 
length, and the abdominal segments gradually decrease in length toward 
the caudal end. The head is nearly hem¬ 
ispherical and rather heavily chitinized. 
The mouth opening is nearly circular and 
surrounded by a raised rim. Owing to the 
minute- size and delicacy of the mouth 
parts, except the strong mandibles, it is 
difficult to determine definitely their ex¬ 
act relation to each other, but they appear 
to be about as in the illustration (fig. 4). The mandibles are long, strongly 
curved, and dark colored. They cross in the middle of the mouth opening. 
The head is from 9.108 to 0.123 mm. in breadth and the mandibles 
0.021 mm. in length. At full growth the larva of the first instar is 
slightly less than 1 mm. in length. 
The larva of the second instar is very 
similar in general appearance to that of 
the first instar, having the same tapering 
form though being somewhat stouter. It 
can, however, be easily distinguished by 
the weaker chitinization of . the oral region 
and the change in the form of the man¬ 
dibles, which at this molt assume a form 
more similar to those of the full-grown 
larva. The brown color of the mandibles is confined to their tips, 
and they are very stout at the base and much less strongly curved 
(fig. 5, a). The head in this instar is from 0.184 to 0.215 broad, 
Pig. 3. —Syntomaspis dfuparunt: Newly 
hatched larva. Highly magnified. 
(Original.) 
Fig. 4. —Syntomaspis druparum: 
Mouth parts of larva of first instar. 
a.Labrum; 6,mandible; c, maxilla; 
d, maxillary palpus; e, labium; /, 
labial palpus. Highly magnified. 
(Original.) 
