allel with the grain of the wood. The total pattern tends to form 
a rough H or / shape. Eggs are deposited in small niches at irreg- 
ular intervals along the sides of the gallery, and the larvae tunnel 
in the phloem until full grown. Pupation occurs in cells hollowed 
out in the inner bark. Young adults feed for a short time beneath 
the bark and then emerge, several often using the same exit hole. 
In northern areas, the winter is spent either in the adult stage 
under the bark of trees killed the previous year, or under bark 
scales around the base of the tree. In the south, it may be spent 
in the bark in all life stages. 
Ips calligraphus (Germ.) occurs throughout eastern America 
and breeds in practically all species of pines within its range. The 
trunks, stumps, and large limbs of recently felled trees appear to 
be favored for breeding purposes, but the trunks of apparently 
healthy pines are also attacked at times. Attacks on living trees 
usually occur on the lower portions of trunks with diameters of 
6 inches or more. In the south, this is one of the first species of 
Ips to attack drought-ridden trees. It is also the first species to 
attack thick-barked loblolly pines. 
The adult is dark reddish-brown to black and from 3.5 to 6.5 
mm. long. The declivity is deeply excavated and coarsely punc- 
tured. Each side is armed with six teeth, and the apical margin 
is strongly produced. The egg galleries, usually three to five, 
radiate from a central nuptial chamber and run longitudinally, 
grooving both the bark and wood (fig. 95). The larval mines are 
broad, tortuous, often long, and transverse. In the south, the life 
cycle may be completed in 25 days, and there may be six or more 
generations per year. 
Ips grandicollis (Kichh.), the southern pine engraver, occurs in 
eastern Canada and in eastern United States from Massachusetts 
to Minnesota, Nebraska and Texas and south to Florida and Mis- 
sissippi. Its hosts are shortleaf, loblolly, Scotch, Virginia, long- 
leaf, pitch, jack, eastern white, and Caribbean pines. Recently 
felled trees and slash are preferred, but the trunks and limbs of 
apparently healthy trees are also subject to attack. Heaviest in- 
festations in large living trees are found on limbs and the upper 
portions of trunks. Spot- or group-killing of pines is characteristic 
of the species. During periods of extreme drought, these groups 
increase in size and abundance. Populations normally develop in 
areas of recent logging operations. 
The adult is dark reddish-brown to black and from 2.8 to 4.7 
mm. long. The declivity is deeply excavated, coarsely punctured, 
armed with five teeth at each side, and the apical margin is 
strongly produced. The egg galleries, three to five, radiate from 
a central nuptial chamber and run longitudinally, grooving both 
the bark and wood (fig. 96). The larval mines are more or less 
transverse. In the south, the life cycle requires from 20 to 25 days 
and there are six or more generations per year. 
Ips avulsus Hichh., the smallest of the eastern species of /ps, 
breeds in all species of pines from Pennsylvania to Florida and 
Texas. Thin-barked slash, such as the limbs and tops of pines, is 
preferred, but groups of young, vigorous trees and the tops of 
large living trees are also attacked frequently and killed. Attacks 
on large trees are usually associated with attacks on the lower 
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