Rhyncophora 
(Snout Beetles) 
Snout beetles differ from other Coleoptera in having the head 
of the adult more or less prolonged to form a beak or snout, the 
gular sutures united in a median line, and the joints of the palpi 
usually rigid. The larvae are whitish, C-shaped, more or less 
cylindrical, and legless. A great many species occur in eastern 
North America, nearly all of which feed on trees and other types 
of vegetation. The larvae usually are burrowing in habit, infest- 
ing fruits, nuts, twigs, roots, and terminals. Trees of all ages are 
attacked, and damage is often severe. Forest nurseries and plan- 
tations are especially susceptible to serious injury (84). 
FAMILY BRENTIDAE 
BRENTID BEETLES 
Only one tree-infesting species of this family occurs in eastern 
United States. The remainder are confined almost entirely to the 
tropics. 
The oak timberworm, Arrhenodes minutus Drury, breeds in 
hardwoods, chiefly oak, beech, and poplar in the Eastern States. 
Adults are dark reddish-brown to black and up to 35 mm. long. 
The snout of the female is straight, narrow, and much longer 
than the head. In the male, it is broader and flatter and armed 
with powerful mandibles (fig. 74). The larvae are elongate, cylin- 
drical, and soft-skinned. 
In Missouri, adults are active from early May to late August 
and the female deposits her eggs in deep holes chewed into the 
wood, often at fresh wounds. Living trees and trees dead up to 3 
years are subject to attack. The larvae bore through the wood, 
constructing pinhole galleries across the grain in all directions. 
The life cycle usually requires 3 years (117). 
F-519917 
FIGURE 74.—Adults of the 
oak timberworm, Arrhe- 
nodes minutus. Male on 
left; female on right. 
208 
