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Joumal of Agricultural Research 
Vol. XXVIII, No. 4 
segment dorsally with only three setae on the poorly defined scutellum. Ninth 
abdominal segment somewhat flattened dorsally and terminated with two pairs 
of long, stiff setae. 
Spiracles of first eight abdominal segments bifore, the fingerlike air tubes 
pointing caudad. 
COMPARISON OF LARVAE OF CONOTRACHELUS ANAGLYPTICUS AND 
C. NENUPHAR 4 
The larvae of Conotrachelns anaglypticus and C. nenuphar (Pis. 2 and 3) are, 
like all species of this genus, very similar in form and appearance. The full- 
grown larva of C. anaglypticus is, however, somewhat shorter and noticeably less 
robust than that of C. nenuphar. The following measurements indicate the 
relative difference in size between the average full-grown larvae of the two 
species: 
C. anaglypticus: Length 7 to 9 mm.; width 1.5 to 2 mm.; dorso-ventral thick¬ 
ness 1.2 to 1.5 mm. 
C. nenuphar: Length 8 to 10 mm.; width 2 to 2.5 mm.; dorso-ventral thick¬ 
ness 2 mm. 
The larval head of C. anaglypticus is much flatter dorso-ventrally than that of 
C. nenuphar and the sides of the head are not so rounded as in C. nenuphar. 
The most noticeable difference between the two species is in the frons. In C. 
nenuphar the dark median line or carina extends from the posterior angle to 
about the middle of the frons, whereas in C. anaglypticus the carina is much longer 
and extends fully two-thirds of the distance from the posterior angle to the 
anterior margin of the frons. Near the anterior margin of the frons there are on 
each side a group of two setae and a sensory spot. In C. nenuphar the setae and 
sensory spot of each group are arranged in the form of a triangle, but in C. 
anaglypticus the setae and sensory spot are arranged in a straight line. 
HABITS AND LENGTH OF LARVAL LIFE 
The white legless larva (PI. 1, C, E, and F) of the cambium curculio is rather 
active and has a habit of throwing itself when disturbed, by straightening with a 
snap from a curved position. Jenne says, “ Full-grown larvae have a habit of 
leaping when irritated. They do this by curling their body up so as to hook the 
anal segment under the head. The body is then snapped out straight, causing 
the larva to jump from 3 to 4 inches along a smooth'surface, or to a height of 
about 1 inch.” The writer noticed that when a piece of bark under which the 
larvae were feeding was removed the insects would one by one throw themselves 
out of sight in the way described. 
Jenne reared 88 larvae in fallen peaches, plums, and apples, most of the number 
being reared from peaches. The duration of larval life in the fruit of these 88 
larvae is shown in Table II. 
Table II.— Length of larval life of the cambium curculio in peaches at Gainesville , 
Ga. f in 1910 
Period 
in 
fruit 
Number 
of 
larvae 
Period 
in 
fruit 
Number 
of 
larvae 
Period 
in 
fruit 
Number 
of 
larvae 
Days 
Days 
Days 
» 11 
1 
19 
7 
25 
4 
* 13 
1 
20 
10 
26 
2 
14 
10 
21 
8 
28 
1 
15 
5 
22 
3 
29 
2 
16 
• 5 
23 
4 
30 
4 
17 
6 
24 
3 
33 
1 
18 
11 
* By R. T. Cotton. 
