Xyleborus affinis Eichhoff occurs in the Eastern United States east of a line from 
Missouri to Texas and south of Michigan and Massachusetts. It breeds in dying 
trees and in green logs and lumber of various hardwood trees such as oak, hickory, 
sweetgum, river birch, hackberry, silktree, persimmon, baldcypress, and black 
locust. Adults are yellowish to reddish brown and are from 2.0 to 2.7 mm long. The 
elytral declivity of the female is dull, opaque, and broadly sloping, and the 
interspaces are armed with a few minute granules. Galleries are similar to those of 
X. ferrugineus except surface galleries are more commonly found and usually more 
extensive. Adjacent tunnels are often interconnected, and there are no cradles (76, 
1356): 
Other eastern members of the genus and their hosts are as follows: X. xy- 
lographus (Say)—oaks; X. pubescens Zimmermann—pines; X. intrusus 
Blandford—pines; X. obliquus (LeConte)—birch, hickory, and chestnut; X. 
rubricollis Eichhoff—oak, hickory, walnut, dogwood; X. /econtei (Hopkins)— 
hickory and palm in Florida; X. tachygraphus Zimmermann, X. obesus LeConte 
(the stout ambrosia beetle), and X. sayi (Hopkins)—a wide variety of deciduous 
trees; X. volvulus (F.)—probably various deciduous trees and shrubs in southern 
Florida; X. devexulus Wood—hickory; X. validus Eichhoff—beech and black oak; 
and X. planicollis Zimmermann, X. viduus Eichhoff, and X. opimus Wood—for 
which the hosts are unknown. 
Xyleborinus saxeseni (Ratzeburg) occurs commonly throughout southern Canada 
and the United States and breeds in a wide variety of trees. Some of its more 
important eastern hosts are pecan, hickory, honeylocust, walnut, sweetgum, 
yellow-poplar, oak, American beech, maple, birch, dogwood, persimmon, holly, 
hemlock, baldcypress, and shortleaf and loblolly pines. The adult is dark brown 
and from 1.6 to 2.4 mm long. It is distinguished from Xyleborus spp. by its conical 
scutellum. The elytral declivity of the female is steep, convex, shallowly bisulcate, 
and armed with two rows of five to seven acute tubercles on each side of the suture. 
The male is smaller with all characters poorly formed. The gallery of this species 
consists of a single tunnel bored | to 7 cm directly into the wood. The innermost 
section of the tunnel is widened vertically upward and downward into a cavelike 
chamber in which eggs are laid and in which the larvae live and feed. The larvae 
feed on ambrosial fungi and wood, enlarging the tabular tunnel of the female. The 
life cycle 1s completed in 2 months. This species can cause severe economic 
damage (/356). 
The genus Xy/osandrus is represented in the United States by five species, of 
which at least four are introduced. They usually breed in twigs, branches, and small 
stems of trees and other plants (/356). The female excavates a tunnel into the pith of 
small stems or into the wood for | to 3 cm. Here a small cavity is made where the 
eggs are laid. The larvae feed on ambrosial fungi growing on the walls of the tunnel 
and also apparently on the host tissue as they enlarge the gallery. 
Xylosandrus zimmermanni (Hopkins) has been recorded in southern Florida, 
Mexico, and northern South America. Its hosts are listed as red maple and ardisia 
species. X. germanus (Blandford) breeds in the branches, logs, and stumps of a 
wide variety of hosts including maple, oak, hickory, beech, dogwood, elm, ash, 
other hardwoods, and pine. It occurs from Connecticut and New Jersey west to 
Illinois and Kentucky. Heavy infestations have been found in elms killed by the 
Dutch elm disease. It is capable of transmitting Dutch elm disease fungus to healthy 
trees (167). It has also been found associated with Fusarium cankers on yellow- 
poplar and black walnut (22). 
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