9242 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
are minute and 38-jointed. They make extensive mines in culms of 
bamboo. 
The adults emerge in the open during the early spring months, but 
inside heated buildings they appear in . February and March. They 
attack well-seasoned bamboo, reducing it to a fine powder which is 
packed solidly behind them, as they bore thr ough the wood. Infested 
material has been taken in this country at Fort Worth, Tex., Los 
Angeles, Calif., Portland, Oreg., Savannah, Ga., and Grand Rapids, 
Mich. It is a serious pest of bamboo i in Japan and India, and now 
is probably becoming established in this country where quantities of 
stock are kept in stor age continually. Fumigation or heat treatment 
(see page 41) may be used to control these insects. 
Coenopoeus palmeri (Lec.), the cactus borer, is a stout, robust. 
blackish beetle from 20 to 25 mm. in length, having the elytra broadly 
sploteched with brownish-gray pubescence. The larvae are large, 
cylindrical, legless borers having the head longer than wide, and very 
flat, and the pr ronotum and ampullae beset with many minute chitinous 
points. The larval mines are extended through the centers of the 
stems of several species of branching cacti in the Southwestern States. 
The adults emerge and fly during the midsummer, laying their eggs 
in small holes onawed in the sides of lar ger branches. “As soon as the 
larva hatches, it bores dir ectly into the center of the stem and ex- 
cavates a large gallery, following the pith. From the point where the 
ege was laid, sap and boring dust 1s exuded—the best indication of the 
presence of the grub. The “pupal cell is plugged off at the top of the 
mine, and the ¢ adult gnaws through the wood and bark to escape. In 
parts of Arizona this borer is very common in shrubby branching 
cacti, such as achoya. It causes large defects in the stems, often pro- 
duces a swelling, and is especially injurious to ornamental gardens. 
It may be controlled by the method outlined on page 25. 
Megacyllene antennatus (White), the mesquite borer, is a large, 
robust beetle from 18 to 23 mm. in length, brownish black, marked w ith 
white or gray pubescence. The thorax i is hght with a dark spot in the 
center. The larva resembles J/. caryae in all essential characteristics. 
It feeds in mesquite and acacia in Texas and the Southwestern States, 
boring beneath the bark and deep into the wood and exuding large 
quantities of granular frass. Craighead and Hofer (7/7) gave meas- 
ures for protecting cordwood and posts. 
The adults fly early i in the fall and again early in the spring, placing 
the eggs in crevices of bark of wood that has been cut not more than a 
few months. [Tor a short time the larvae feed beneath the bark but 
soon enter the wood and excavate extensive mines. Great quantities 
of frass are exuded through a hole in the bark, which is gradually 
enlarged and through which the adult finally emerges. The pupal 
cell is made late in the summer behind a wad of fibrous frass. 
This insect chiefly injures mesquite cordwood, and in a region where 
other fuel woods are scarce, it becomes a serious pest. Stores of cord- 
wood are often so badly damaged by this larva that the fuel value is 
reduced 50 percent or more. Fence posts are also greatly ven 
or destroyed. Proper seasonal cutting will prevent attack by these 
insects. ‘Trees cut from November 15 to January 15 will rarely be 
attacked, and wood for fuel should be cut during this period. 
The painted hickory borer (J/eyacyllene caryae Gahan) resembles 
