44 
BULLETIN 427, U. S. DEPARTMENT OF AGRICULTURE. 
MICROGASTER sp. 1 
This, the most active parasite attacking the tuber moth, pre- 
fers half -grown leaf -mining larvae. This parasite seems the best 
fitted naturally to be a dangerous enemy of the tuber moth, but dur- 
ing three years' observation has not reached expectations. 
The adults (fig. 39) are readily reared at anytime from late summer to 
spring, but never in large numbers. The adult has the shortest length 
of life of any observed. Even when fed, 
only one individual lived as long as 11 days. 
It seems to be fairly well distributed through 
the San Gabriel Valley. 
The record of a typical life cycle follows : 
1915. 
August 18. — Tuber- moth larvae parasitized by Micro- 
gaster sp. 
September 3. — 1 adult issued. (Male.) 
September 4. — 2 adults issued. (Male and female.) 
September 6. — 1 adult issued. (Male.) 
Life cycle 16 days at an average temperature of 73° F. 
DIBRACHYS CLISIOCAMPAE FITCH. 2 
The last well-ascertained parasite of the 
tuber moth was Dibracliys clisiocampae 
Fitch. During 1913 one fe- 
male was reared from tuber- 
moth material, but could not be bred through, and as 
no more issued, it was given up. 
In the winter of 1914 specimens were captured on 
potato foliage, and it was later noticed breeding on 
stored potatoes in the insectary. The parasite ovi- 
posits in the mature larvae in cocoons, and in pupae 
and issues from both stages, but usually from the 
mature larvae. This parasite works both in the field 
and in storage. It seems to prefer piles of potatoes, 
working all through them, and also has been noted to 
oviposit in dark bins. The egg is shown in figure 40. 
The adult (fig. 41) is persistent, and if driven away 
from a cocoon will return again and again until it ovi- 
posits. Fourteen mature larvae (fig. 42) have been 
reared from one host. These pupate (see fig. 43) with- 
out spinning cocoons, and within the cocoon of their host. The 
parasite does not seem to be very well distributed, having been 
found only in Whittier and Pasadena, Cal. It seems at first glance 
to be the most effective parasite of the tuber moth, but probably this 
is not the case. It is not as effective a i others under field conditions, 
Fig. 37. — Lateral view of mature 
larva of Apanteles sp. (Chttn. 
No. 2230" 7 ), with view of fan at 
left below. Much enlarged. 
(Original.) 
Fig. 38.— Apanteles 
sp. (Chttn. No. 
2230"7): Lateral 
view of pupa. 
Much enlarged. 
(Original.) 
Chittenden No. 2230 08 . 
2 Chittenden No. 2230°9. 
