The six-spined ips, Ips calligraphus calligraphus, the largest of the southern Ips species is native to the Americas. Ips beetles usually attack weakened, dying, or recently felled trees and fresh logging debris.
Life Cycle
Ips c. calligraphus adults are about 0.2 in. (5 mm) long and have 6 spines on each side near the posterior. Their eggs are oblong, pearly white, and about 0.04 in. (1 mm) long by 0.02 in. (0.5 mm) wide. Egg galleries, usually three to five, radiate from a central mating chamber and run up and down, grooving both the bark and the wood. The life cycle may be completed in 25 days, with six or more generations per year. The grub-like larvae are small, whitish, and legless, with orange-brown heads up to 0.04 in. (1 mm) wide. The pupae are waxy white and similar to adults in size. The eastern six-spined engraver commonly infests thick-barked pines and usually attacks portions of trunks that are 4 in. (10 cm) or more in diameter. This is often one of the first bark beetles to attack drought-stricken trees.
Distribution
Ips c. calligraphus is primarily an eastern subspecies that occurs naturally from southern Canada to the Gulf of Mexico. A small population has apparently been introduced into California.
Control Efforts
Beetle-caused damage can be reduced through one or more prevention or suppression techniques. Other control methods are burning, chipping, debarking, or burying infested portions of trees. Burning should be restricted to periods of low fire danger, and Federal and State laws should be observed. Land managers may consult their nearest county, State, or Federal forestry personnel for recommendations on management practices to be followed in a particular stand or area.