The Locust Borer 5 



DESCRIPTION OF BORER 



Adult. The beetle is about four-fifths of an inch in length and is 

 blackish in color with yellow crossbars on the thorax and wing cov- 

 ers. The male is a little smaller than the female. The third crossbar 

 on the elytra, or wing covers, is W-shaped. The elytra taper gently 

 from the base to the rounded tips. Legs and antennae are reddish- 

 brown. '''; 



This insect is quite similar to the hickory borer (Cyllene pictus), 

 but is easily distinguished from it since this borer appears in the fall, 

 while the hickory borer appears in the spring. 



Egg. The egg (shown in Figure 2) is about one-twelfth of an 

 inch in length, somewhat tapering at one end and blunt at the other; 

 color, white; surface, smooth. 



Larva. The larva (also shown in Figure 2), is a white, footless 

 grub about one and one-fifth of an inch long when mature. Nine 

 spiracles are present along the sides of the body. The one nearest 

 the head is a little lower than the others. The head is small and 

 dark colored. 



Pupa. Is seen in Figure 2, and is similar in color to the larva. 

 The average length is nearly one inch. The appendages, except the 

 wings and elytra (wing covers), are well formed but folded against 

 the body. The wings are very feebly developed, while the wing 

 covers are small, oblong pads about one-third of an inch long. 



LIFE HISTORY 



Adult. The adult beetles appear about the middle of September. 

 By means of screen wrapped around the trunks of a number of trees, 

 and which were examined daily, it was possible to obtain accurate 

 data regarding the date of appearance of the adults. Their food con- 

 sists of pollen of flowers, chiefly that of the common goldenrod. The 

 insects soon mate. The females then run about over the trunk and 

 larger branches of the trees searching for places in which to deposit 

 eggs. Mating may take place a number of times during the oviposi- 

 tion period. In one particular instance a pair was seen to copulate 

 twice within three minutes. They remain in copula only a few sec- 

 onds. The beetles are active during the warmer part of the day. 

 Late in the afternoon they seek shelter in rubbish on the ground and 

 remain there during the night. 



Egg. The eggs are generally placed singly in V-shaped crevices 

 in the bark. (See Figure 2.) In some cases, however, a number of 

 eggs may be placed in a group in an old wound. It requires only a 

 few seconds for the deposition of an egg. The average number de- 

 posited by a single female has not been determined, but it is about 

 one hundred. Eggs hatch about six or seven days after deposition. 



Larva. The young larva bores through the bark and remains 

 active until cold weather. Then it ceases tunneling and lies in a dor- 

 mant state throughout the winter. 



During the fall the location of larvae can often be discovered by 

 the presence of small, moist spots on the bark, as well as small 

 masses of sawdust pushed out by the young borers through the open- 

 ings of their tunnel. In the spring the larvae become active and 

 burrow deeper into the tree, often penetrating the heartwood. From 

 here the tunnels run upward from four to six inches. The larvae 

 remain active throughout the summer, maturing about the middle of 

 August. 



