OF WASHINGTON, VOLUME xi, 1909. 59 



The larvae of this group usually make their pupal cells deep 

 in the sapwood. While making these cells they assume the 

 looped position similar to those of the opposite group. To 

 determine whether these larvae would pupate in this position, 

 two full-grown larvae of Fornax badins were taken from their 

 pupal cells and placed in similar shaped ones made with a knife 

 in Liriodcndron (the host from which they were taken), one 

 in a straight position and the other in a hooked one, and the 

 latter was observed to change its position to a straight one 

 before pupating. This species has been reared to the adult 

 stage during the first week in June. All present observations 

 indicate that there is but one generation a year, the immature 

 stages lasting from ten to twelve months. 



The mouthparts of the larvae of this group are quite micro- 

 scopic, and when viewed through an ordinary hand lens the 

 head appears perfectly solid, and the mandibles, surrounded 

 as they are by twelve other saw-like teeth, seem to be immov- 

 able fixtures. The larvae of this group apparently employ a 

 different method in excavating their galleries from those of the 

 opposite one. Instead of depending entirely upon their mandi- 

 bles, which are comparatively small and feeble, these larvae 

 utilize the chitinized teeth with which the head is armed, the 

 head being connected with the thorax in a manner somewhat 

 corresponding to the ball and socket joint of vertebrate animals. 

 This enables the larva to move its head freely and in any 

 direction, and also gives it additional strength. Assisted by 

 the powerful muscles of the body and the hardened, chitinized 

 body-wall, it is capable of sawing even into solid wood. No 

 parasites have thus far been bred from species of these genera. 



The borers, in decayed wood are harder bodied and more 

 chitinous than those of the opposite group. They also possess 

 much smaller mouthparts, the mandibles being much shorter, 

 but having the same outward curve. On the ventral side of 

 the last segment is a shallow, spoon-shaped depression, chitin- 

 ous and roughened around its border and finely punctured in 

 the center. The body is of a uniform shining straw-color, 

 with dark brown markings on the thorax and head and dark 

 brown mandibles and caudal end. All the larvae of both groups 

 possess nine pairs of spiracles. 



In the borers of solid wood, with the exception of Nematodes, 

 the body is softer, less chitinous, and lighter in color. In 

 Melasis'and Tharops the full-grown larvae are usually trans- 

 lucent or wax-color, with head and mandibles dark brown. In 

 the larvae of these genera there are a pair of slightly raised 

 chitinous T-shaped markings on both the dorsal and ventral 



