and the legs are slender. Larvae are also elongate and slender; | 
the head is globular; the ninth abdominal segment is conspicu- | 
ously armed; and the tenth segment is ventral. 
The chestnut timberworm, Melittomma sericeum (Harr.), once a 
destructive pest of chestnut, is now found chiefly in white oak. | 
Adults are brown, clothed with fine, silky hair, and about to 11 
to 15 mm. long. Eggs are laid in cracks on the surface of the 
wood. The larvae bore deep into the wood, enlarging their tunnels 
as needed. Pupation occurs in cells constructed near the surface. 
The sapwood timberworm, Hylecoetus lugubris (Say), tunnels 
under the bark and across the sapwood of various hardwoods such 
as poplar, birch, tulip-poplar, basswood, buckeye, and black wal- 
nut. Eggs are laid from April to July in the crevices of bark on 
dying trees or on green logs left lying in the woods. Damage is 
caused by pin hole defects. Each larva has a slender, barbed spine 
on the ninth abdominal segment. 
FAMILY MORDELLIDAE 
TUMBLING FLOWER BEETLES 
Members of this family are commonly called tumbling flower 
beetles because they are usually found on flowers and because of 
their speed in running, Jumping, or tumbling. They are usually 
dark-colored, wedge-shaped, long legged, and from 3 to 14 mm. 
long. The larvae of certain species are predaceous on other insects. 
Powder-post Beetles 
A number of species of Coleoptera belonging principally to the 
families Lyctidae, Anobiidae, Ptinidae, and Bostrichidae are com- 
monly known as powder-post beetles. The term powder-post, in 
its broadest sense, is used to designate the type of damage in 
which the interior of wood is reduced to a flour-like powder, some 
of which is easily jarred from the wood in handling (40). It may 
occur in the sapwood or heartwood of either hardwood or soft- 
woods. Damage results from tunneling by the adults of certain 
species and by the larvae of all species. Surface holes made by 
emerging beetles also mar the surface of the wood. These holes 
range in diameter from less than 1 mm. to several millimeters, 
depending on the species involved. 
A few species of cerambycids, buprestids, and curculionids also 
have the powder-posting habit. They are discussed in the sections 
devoted to these families. Members of families Lyctidae, Ano- 
biidae, Ptinidae, and Bostrichidae, which are discussed below, 
comprise the majority of destructive species. 
Key to Genera of More Important Powder-Post Larvae 
The four families and their more important genera, into which 
powder-post beetle larvae are usually divided, are character- 
ized and separated in the following key. The genera and species 
are not described, because they have not been thoroughly worked 
up and are difficult to characterize on the basis of present 
knowledge. 
126 
