New Yorx AGRICULTURAL EXPERIMENT STATION. 299 
Weed has stated; accounts in part, at least, for the large numbers 
of caterpillars that are seen crawling up the trunks of infested 
trees. Observations upon caterpillars in confinement showed that 
much less silk is spun after the last molt while crawling about’ 
than during the earlier stages. 
Sharing a nest with the apple-tree tent-caterpillar.—What ~is 
probably a very unusual occurrence is shown at Plate X XII, fig. 1. 
This nest was made by a colony of apple-tree tent-caterpillars. 
It will be observed that most of the caterpillars in sight are not 
the rightfu] owners of the nest, but are forest tent-caterpillars. 
The two species can be easily distinguished as the apple-tree tent- 
caterpillars have a conspicuous white line extending the whole 
length of the back, while the forest tent-caterpillars have the lne 
replaced by a row of white spots. This nest was on an apple 
tree near the Station grounds. At the time this picture was 
taken, about 10:30 «a. m., the caterpillars had collected on the 
sunny side of the nest. There were none on the opposite side. 
The writer watched this nest for several days and it was observed 
that the “ guests” 
went out regularly with the other species 
to feed and returned with them. Upon no occasion, however, were 
the forest tent-caterpillars seen to enter the nest. Upon the 
fourth day the nest was cut open and although it was well filled 
with apple-tree tent-caterpillars none of the forest tent-cater- 
pillars could be found. A few days after these observations were 
made Mr. G. G. Atwood reported finding a similar case in an 
apple orchard a few miles distant. Although it is not uncom- 
mon to find two or three stray forest tent-caterpillars upon one 
of the nests of their near relatives, such cases as the above appear 
to be quite unusual. 
Congregating habit—aA very noticeable habit is that of con- 
gregating in large numbers on the trunks and branches of the 
infested trees. There appear to be two principal occasions for 
this, first, when resting during the heat of the day and, second, 
when about to molt. As an indication of the former, the writer 
