280 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
throughout the group, being typically curved like a closed finger, 
fleshy, and soft-textured. The thoracie and abdominal segments bear 
conspicuous transverse folds or ridges. The first, or mesothoracic 
spiracle, is apparently pushed forward into the prothorax. Legs are 
wanting except in the Brentidae and Anthribidae, and in these they 
are two- or three- jointed. The head is usually globular, having a well- 
developed hypopharyngeal bracon, but no chitinized sclerite on the 
hypopharynx. The clypeus and labrum are distinct, and the ventral 
mouth parts are fused into a fleshy trapezoidal unit. The maxillary 
mala is undivided, and, except in the Anthribidae, the mandible is of 
a simple biting type, without a molar structure. There are several 
families of Rhynchophora of economic importance in the forests, in- 
cluding many of our most destructive beetles. 
Famiry BRENTIDAE 
The Timber Worms 
The timber worm family of long slender beetles is almost entirely 
tropical. The beak is straight, directly continuing the long axis of 
the body, often so thick at the base as to comprise an elongation of 
‘the head. The thorax and the abdomen are elongated. 
The oak timber worm (Arrhenodes minuta “(Drury )) is the only 
native species affecting forest trees in the eastern part of the United 
States. There is considerable variation in size in each sex, the males 
measuring from 7 to 18 mm. and the females from 6 to 14mm. The 
adults are shiny reddish brown with the elytra marked by narrow, 
elongate, yellowish spots, often united to form two or three nearly 
complete cross bars. The thorax is longer than broad, the elytra are 
not wider than the thorax, and are more than twice as long as wide. 
The head of the adult female is prolonged into a slender snout, whereas 
that of the male is broad and flat, and has powerful jaws, which are 
said to be used as Weapons in protecting the female. 
The larva is an elongate, cylindrical, soft-skinned form with the 
thoracic segments both above and below and the abdominal segments 
above pr ovided with minute chitinous asperities. The head is glo- 
bular and protruding. The tenth abdominal segment is large, some- 
what wider than the others. The legs are minute > and two- jointed. 
The eggs are deposited in May and June in cylindrical holes made 
by the slender snout of the female in recently felled or dying hard- 
woods, chiefly oak, beech, and poplar. The larvae bore into the sound 
wood, and extend their pinhole burrows in all directions. At times 
white oak stave bolts are seriously damaged (Blatchley and Leng, 49). 
The work is quite similar to, and is often confused with that of the 
chestnut timber worm. Occasionally in local sawmill operations a 
very high percentage of oak timber may be found so damaged by these 
pinholes that it is unfit for tight cooperage or other special purposes. 
Infestations of this kind usually 1 ‘esult from mechanical injuries on the 
living tree, such as fire scars, which expose the sapwood to ov iposition 
of the beetles. Control measures that may be employed against the 
oak timber worm are given on page 27. 
Brentus anchorago ie) is a tropical American species occasionally 
found in southern Florida under the bark of various trees. It is simi- 
lar in appearance to the oak timber worm. 
