326 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
bution, having been taken in South Carolina, Georgia, Florida, and 
Texas. The known hosts are oak and red bay. 
The genus Thysanoes Lec. is closely allied to Micrasis and Hylo- 
curus, but differs in the absence of the acuminate apex to the lye 
It is similar in habits to the two last-named genera in that the brood 
burrows are in the wood. This insect is only mildly 1 injurious, and no 
control is necessary. TVhysanoes fimbricornis occurs from Penn- 
sylvania southward to Florida and westward to Texas. The known 
hosts are oak, hickory, redbud, and acacia. 7. lobdelli is known 
only from Mississippi and Georgia, breeding in oak and maple. 
T. berschemiae breeds principally in rattan vine, but has been taken 
from elm. Its range is from Virginia to Florida and westward to 
Mississippi and Texas. 
Pseudothysanoes Blkm. is a genus closely allied to Thysanoes, and 
although the eastern species breed in the bark rather than the wood, 
they should be mentioned here. ‘Two of the eastern species occur in 
bark of basswood, whereas the third is found in several other hard- 
woods. These insects are not known to cause any real injury. 
P. rigidus breeds in basswood from Canada to Michigan, Ohio, and 
West Virginia. P. drakewi is found in basswood bark in central 
New York. P. lecontei has been taken from chestnut, oak, hackberry, 
walnut, and hornbeam from Maryland and West Virginia to North 
Carolina. 
Cryptocleptes Blkm. is a genus of very small, rather slender, brown 
beetles, found in forked, longitudinal burrows in the bark of dying and 
recently cut hickory twigs. “Insofar as is known, the single species is 
not responsible for any real j injury, and no control is necessary. Cryp- 
tocleptes dislocatus was described from Mississippi and is also known 
in Texas, North Carolina, South Carolina, and West Virginia. Hick- 
ory is the common host, but in Texas it was found in acacia. 
Another species that burrows in the wood is Lymantor decipiens. 
Structurally it is not at all closely related to Micrasis and its relatives, 
but more closely to Dryocoetes. It is reddish brown, less than 2 mm. 
long, rather slender, with the posterior pronotum and wing covers 
deeply and coarsely punctured. It is known throughout the Eastern 
States from Massachusetts to Iowa and south to Mississippi. Known 
hosts include hickory, pear, and maple. In maple the egg galleries 
and larval mines are both in the outer sapwood of twigs that have 
already begun to decay. 
Further information on these beetles may be found in the writings of 
Blackman (37, 38). 
The Dead-Twig Borers 
Various species of two closely related genera of small bark beetles 
are found in dying and dead twigs, dead ‘bark, seeds, and dead hulls, 
such as cotton bolls. Nearly all are of little economic importance, 
being mildly beneficial as promoters of decay, but a few become inju- 
rious when they attack seeds and other stored vegetable products. 
Numerous species of Zypothenemus Westw. are very common in the 
Southern States. They are very small brown or black beetles from 
less than 1 to nearly 1.5 mm. in length. The species are difficult to 
distinguish, and as they have little economic importance will not be 
