88 INJURIOUS INSECTS OF 1909 AND IQIO. 
hole of the lower caterpillar was nine inches above the ground, 
and the upper one was thirteen and one-half inches above, and the 
galleries went upward from the entrance-holes. On August 17th 
none of the larvae which had been reared from the eggs were found 
present in any of the plants. Some of the borer holes were entirely 
vacant, and a few had pupae in them. This shows that a Papaipema 
nitela larva naturally attacks but two plants in the course of its life. 
Papaipema nitela. 
The last larva of this species seen during the season died in cap- 
tivity on September 7th, twenty days later than the last larva pupated 
in the season of 1908. ‘The first pupa was found on August 11th 
(three days later than last year). The first moth of this species 
emerged in captivity on August 24th (one week earlier than last 
year). The last moth emerged on October Ist. 
The average length of the pupal stage this year was about the 
same as it worked out to be last season. This season it varied from 
twenty to twenty-six days, the average being twenty-three days. 
This species was reared during the season from the following food- 
plants: Nicotiana, Lamb’s Quarter, Tomato, Giant Ragweed, Cockle 
Burr, Giant Bur-Elder, Peony, Burdock (the Giant Bur-Elder was 
this year, the same as last, the most badly attacked food-plant). 
Typical Papaipema nitela larvae were found in the stalks of 
giant ragweed as follows: One with an entrance-hole ten inches 
from the ground, burrow seven inches long, ascending. This was 
found on August 1st. Two larvae of this species were found in giant 
ragweed with their entrance-holes twenty-one inches above the 
ground, and with burrows five inches long, ascending, and three were 
found on the same date with the entrance-holes six feet above the 
ground, and burrows three and one half inches long, and also ascend- 
ing. On August Ist there were found twelve Papaipema nitela, 
larvae in a single giant ragweed stalk three feet high. Some were 
in the stalk proper, and some were in the branches. We found many 
burrows formed apparently by both Papaipema nitela and Papaipema 
cataphracta larvae in wild hemp and other plants on September 3d. 
This goes to show that a large percentage of the larvae of these 
species go into the ground to pupate. The burrows which were 
formed earliest were at this date nearly closed up by the growth of 
the plant on the interior of the stem. 
