Tue Rissep PInE-BoRER 379 
makes it difficult for this insect to work, but develops fungi which attack 
all stages of the insect, especially the larvae (Plate VIII, 8). This is 
especially true in the case of trees with thin bark, for such trees are less 
resistant to moisture and the insects may become wet. Under such con- 
ditions the larvae, the pupae, and even the adults often die from fungus 
_ attacks. Those that survive until winter are often killed by frosts, which 
under such conditions are destructive to them. 
The newly hatched larvae, while searching for an easy access to the inner 
bark, often expose themselves to predatory enemies which help in reducing 
their numbers. Birds, chiefly the woodpeckers, are probably the most 
important of these predatory enemies (Plate VIII, 7). It is not uncommon 
to find infested trees where these birds have removed from one-half to 
two-thirds of the larvae and adults during a single winter. Ants are 
usually common on the trees where the adult beetles are ovipositing. 
Though the insect tries to place her eggs in a secluded crevice, the newly 
emerged larvae often expose themselves. Ants have been observed carry- 
ing off both eggs and young larvae, chiefly the latter, as food. 
Numerous centipedes, and larvae of staphylinids and carabids, are 
frequently found under the bark with the larvae of this insect, and may 
feed on them. 
Though the insect constructs about itself a defensive wall, it seems 
probable that this wall is often ineffective against these enemies, especially 
in trees on which the bark has become loosened. Large carpenter ants 
have been found in the pupal cells of the ribbed pine-borer, but whether 
or not they are definitely harmful is not known. 
A larval parasite, Atanycolus simplex Cresson,? which was reared from 
certain larvae, seemed fairly effective in reducing the numbers of this 
insect, especially farther south in Pennsylvania. In no case, however, 
were more than about five per cent of the jarvae found infested. In New 
York this parasite is exceptionally rare, infesting only about one per cent 
of the larvae. When this parasite is mature it emerges from the larva 
and constructs a pupal cell underneath the bark (Plate VIII, 9). This 
occurs during the early fall. The adult emerges the following June. The 
remnants of the old Rhagium larva can often be seen attached to the pupal 
case of this parasite. 
2Tdentified by S, A. Rohwer, of the Bureau of Entomology, Washington, D. C, 
