INSECT ENEMIES OF EASTERN FORESTS 335 
the Southern States and as far north as Massachusetts and New York. 
Any of the pines in its range may be attacked. 
[ps avulsus is the smallest of the eastern species of ps, rang- 
ing from 2.1 to 2.8 mm. in length. It is brown to black, and has four 
small teeth at each side of its rear end. It breeds from Pennsylvania 
to Florida and westward. Various species of pine are affected, the 
parts attacked being branches from 1 to 6 inches in diameter. This 
species is less aggressive than the other southern forms. 
Ips pind ranges in length from 3.5 to 4.2 mm. and in color from 
brown to black. It has four teeth at each side of the rear end, these 
being considerably coarser than in /. avulsus. It is found in the 
FIGURE 66.—Galleries of [ps pini on white pine. 
Northern States from Maine to Minnesota. The favorite host is white 
pine (fig. 66), but other pines in its range, and occasionally spruces, 
are also attacked. It is less aggressive than J. calligraphus but when 
present in great numbers will attack living trees, especially if these 
are decadent. J. chagnoni, like I. grandicollis, has five pairs of 
teeth on its rear end, but it is larger (4 to 4.8 mm. long) and stouter. 
It attacks white pine, red pine, and white spruce, and is known from 
eastern Canada and the northern part of New York, New England, 
and Minnesota. /. dongidens is slightly more than 3 mm. long 
and is reddish brown. It differs from all other eastern species by 
having the body nearly squarely truncate behind, and by having only 
three teeth on each side, of which the third is the longest. It is fairly 
common in central New York in the lower trunks of white pine and 
has been reported as infesting hemlock in Nova Scotia. 
The genus Orthotomicus Ferrari contains only one eastern species, 
O. caelatus Eichh. In general form the genus resembles /ps in that the 
rear end is truncate, with the sides armed with teeth, but the shelflike 
792440°—49___99 
