240 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
tennae and tips of the elytra are provided with spines. The larva 
can be recognized by its elongate, slender, cylindrical form, with the 
last segment heavily chitinized and bearing many minute spines. The 
head is wider than long, having the mandible rounded at the apex and 
bearing one ocellus on each side. The posterior area of the pronotum 
is white, shining, and finely rugulose, as are the ampullae. Legs are 
present. It feeds in mesquite in Texas and the Sous n States. 
The adult flies early in the summer and deposits the eggs in crevices 
of the bark at the forks of small living branches. The larva hollows 
out the stem, working downward through the green wood and at 
intervals opening small holes to the surface for the exudation of frass. 
From these holes a black, watery liquid drips, staining the foliage or 
soil beneath. Stems 2 inches in diameter and the main trunks of small 
trees are often found infested. The interior of the larvae mine is 
always black and stained. ‘Two years is required to complete the de- 
velopment. Branches and young trees are occasionally killed by this 
borer. Defects caused by it in the wood of larger trees are enlarged 
by the entrance of secondary insects, such as ants. About buildings 
the dripping of the black liquid from the laval mines is the most ob- 
jectionable feature. Control measures for this borer may be found 
on page 24, 
The two insects Callidium antennatum Newm., the black-horned 
pine borer, and @. janthinum Lec., the black-horned juniper borer, 
are so similar in all characteristics that they can be treated together. 
They are flattened, blackish-blue beetles, from 9 to 14 mm. in length, 
having the thorax rounded and with an impression on each side of 
the middle (fig. 52, #). The larva is rather depressed, with a tough 
skin of shining texture. The head is wider than long, the mandible 
rounded at the apex, with one ocellus and four small tubercles on the 
under anterior margin of the head. Feeding beneath the bark and in 
the sapwood of dry coniferous wood, they make extensive mines and 
exude large quantities of granular frass. They feed in pines, spruces, 
hemlocks, junipers, and cedars throughout the United States. 
The adults appear early in the spring, laying their eggs beneath 
scales of bark on wood that has seasoned over winter. The larvae 
feed beneath the bark, deeply scarring the wood, and making long’ 
prepupal chambers in the sapwood. Large quantities of oranular 
frass are exuded from small holes in the bark, which are enlarged as 
the larvae grow and which mark the opening of the pupal cells. The 
pupal cell is plugged deep in the wood with a wad of fibrous frass. 
Normally the life “cycle is completed in 1 year. Considerable injury 
is caused by these insects to rustic work and houses built of coniferous 
wood. The wood is badly riddled and weakened and the bark is so 
loosened that it falls away. Lumber sawed and stored with the wane 
is frequently injured. For control measures see page 38. 
Chlorophorus annularis (I*.), the bamboo borer, is an elongate, 
subeylindrical, blackish beetle, about 10 mm. in length, with X- sha aped 
markings of yellow on the wing covers. The thorax has pale greenish 
markings. The outer part of ‘the 11- jointed antenna is black and the 
inner is red. The first two pairs of legs are red and the third pair 
black. The mature larvae are about 20 mm. long, and are slender 
and tapering. The head is wider than long, the m: andible rounded at 
the apex, and there is one ocellus on each side of the head. The legs 
