LIFE HISTORY AND HABITS: THE LARVA. 55 
Table XIX. — Course in fruit taken by newly-hatched plum-curculio larvx — Contd. 
Dates of 
observa- 
tion. 
Kind of fruit. 
Location of 
puncture. 
Fruits 
exam- 
ined. 
Course taken by larvae in fruit. 
May IG 
20 
2G 
Red June plum 
Early Belle peach 
Wild plum 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
1 
In to base of pit. 
Center side 
BasalJ 
Apical § 
Basal § 
Apical % 
do 
In to pit. 
Under skin about T V inch, and around to 
27 
center of side, then into pit. 
Into pit. 
28 
do 
Straight in and into pit. 
30 
do 
Straight into pit. 
30.. 
do 
In straight to apex of pit, and then around 
do 
Apical % 
to center of other side of fruit. 
Into apical J of pit, then along pit to center 
3 
... do 
of side. 
Into pit; around to center side and into pit. 
6 
...do 
Center side 
do 
Into about center of fruit, then to basal J, 
9 
do 
and down toward pit. 
Straight into pit, then along pit to apical J; 
then down side of pit. 
Prof. Oandall has recorded observations on the course taken by 
larvae hatching in apples, as follows: 
The course taken by the larvae on emerging from the egg has been traced in a number 
of apples, and is found to be variable. In one apple examined the bore proceeded 
straight from an egg cavity near the basin to a point just beneath the skin on the 
border of the cavity. Another bore was traced in a spiral 2\ times around the fruit. 
Other bores were found to be tortuous, but in no apple examined did the early bore 
extend to the core. 
LARVAL INSTARS. 
The number of molts made by the curculio larva in the course of 
its growth has not heretofore been determined, probably on account 
of the difficulty of following the growth of the insect in the fruit. 
Mr. Hammar, during 1910, in Michigan,. determined the number of 
molts and length of the respective instars for 10 individuals, as 
shown in the following table: 
Table XX. — Larval instars of the plum curculio. 
Dates of molting. 
Individual No. 
Hatched. 
First 
molt. 
Second 
molt. 
Third 
molt. 
Left 
fruit. 
Adult. 
l 
June 2S 
June 30 
.. do 
June 30 
July 2 
July 2 
July 4 
.. do 
July 5 
Julv 8 
July 7 
July 10 
Julv 9 
July 8 
July 9 
July 11 
July 12 
July 8 
...do 
...do 
Julv 15 
Julv 14 
Julv 11 
Julv 12 
Julv 16 
Julv 18 
Julv 17 
Aug. 4 
Aug. 10 
Lug 14 
2 
3 
4 
July 1 
do 
July 3 
July 7 
July 6 
...do 
Julv 7 
July 8 
July 9 
5 
Aug. 16 
Aug. 12 
Aug. 15 
Aug. 89 
\U" li 
6 
July 2 
do 
July 4 
do 
7 
8 
July 4 
July 5 
...do 
July 6 
July 7 
...do 
9 
10 
Aug. 16 
