86 INJURIOUS INSECTS OF I909 AND IQIO. 
the middle of the leaves, the seedlings being scarcely one inch tall 
at this time. A drawing of one of the young worms was also made. 
They were about 214 mm. long at this time. In hatching they left 
large holes in the sides of the egg-shells. These eggs continued to 
hatch until the 29th of May, and there were in all about 100 cater- 
pillars which hatched from them, and the leaves of several young 
giant bur-elder seedlings, which were in the breeding-cage at the 
time, were completely riddled by the mining of these caterpillars. 
The caterpillars in their earlier stages have a looping movement, 
much like that of Geometrid larvae. All the larvae, which had not 
Fig. 39. Partial view of plots used in experiments, showing barriers, etc. 
at this time established themselves as miners in the leaves of seed- 
lings, were taken and placed on selected seedlings of giant bur-elder ; 
these seedlings being all in good condition on May 28th. The larvae 
were placed on these seedlings at about 5:30 P. M. on May 28th, 
and were examined about 8 A. M. May 2oth, and were found to 
have already established considerable galleries in the leaves of the 
seedlings. There were eighty-four larvae in all placed upon seed- 
lings in this way. 
Some of the leaves were photographed, showing the leaf-mining 
work, with mines well formed, and some of the larvae in them. 
