THE CHERRY LEAF-BEETLE. 7 
the other thoracic segments, and all abdominal segments except the ninth and tenth. 
The head is provided with a few scattered long bristles. The ninth abdominal seg- 
ment is rounded behind and concave above, very heavily chitinized, and with a row 
of long bristles around the edge. Below it is rather conical, with 
the very small tenth segment forming the apex of the cone. The 
latter bears the anus, which is modified to form an auxiliary organ 
of locomotion. On each side, between the prothoracic and meso- 
thoracic segments, can be seen a small tubercle surrounding the 
mesothoracic spiracle, and each of the first eight abdominal seg- 
ments is provided with a pair of spiracles. On each side of the 
middle the prothorax is irregularly impressed. This concavity 
persists through all stages. 
At full growth (fig. 4) each instar is very much distended, the 
yellowish skin becomes visible, and the dark color is confined to yg. 3.—The cherry 
plates and patches, the head, and the legs. Theabdomenisparalle!l __leaf-beetle: Newly 
sided and wider than the thorax. The head and ninthabdominal hatched larva. 
segment, at least above, do not share in this distension, but retain tune see 
the size originally assumed after the molt. The dorsal surface of 
the prothorax is covered by a single large, dark-colored plate, flanked on either side 
by the dark colored, chitinized tips of the lateral prominences. Just below the latter 
are two small plates partially surrounding the base of the coxa. Ventrally the dark 
color is confined to a nearly square median patch with a 
very small oval patch behind it. In the mesothoracic and 
metathoracic segments the dorsal plate is broken up into 
two double transverse rows of three plates each, the middle 
one in each row being much the largest, and transversely 
elongate. The lateral edges of the dorsum are very heavily 
chitinized and dark colored. Below the latter are two 
smaller plates, the anterior one of which on the mesothorax 
bears the spiracle, the other being the tip of the lateral 
— =. —— y~ prominence. Each of the coxe is partially surrounded 
a 
A} SS 
= above by two small plates as in the prothorax. Ventrally 
there are three plates, a large transverse anterlor one and 
a pair of small, nearly oval ones posteriorly. The dorsal 
plate of each of the first eight abdominal segments is simi- 
lar to that of the mesothorax and of the metathorax, being 
broken up into two double rows of plates, but on the lateral 
edge of the dorsum are two very small plates, the posterior 
one of which bears the spiracle. Beyond these is the 
chitinized apex of the lateral prominence. Below the color 
is distributed in a transverse row of fivespots. The ninth 
segment has ventrally a crescent-shaped. plate in front of 
and partially surrounding the very small tenth segment, 
which bearstheanus. The tenth segment is heavily chiti- 
nized laterally and posteriorly. (Fig. 5.) 
The newly hatched larva is shown in figure 3. The com- 
\ parative size of the three larval stages is indicated by fig- 
Fic. 4.—The cherry leaf-beetle: wre 6, which shows the heads and ninth abdominal seg- 
= ee ori iol en- ments drawn to the same scale. 
: 1 First instar.—The first larval instar (fig. 3) varies with 
age from 2 to 3 mm. in length with the head 0.38 mm. and the ninth segment 0.36 mm. 
broad. (Fig. 6, a.) 
