IMPORTANT PECAN INSECTS AND THEIR CONTROL. 



45 



FIG. 54. The hickory twig-girdler. Adult, or beetle. 

 Enlarged. 



the male. They have long an- 

 tenna* or foolers; those of the 

 males are considerably longer 

 than the body, but those of the 

 female are only a trifle longer 

 than the body. The body is 

 subcylindrical, and the general 

 color is grayish brown, there be- 

 ing a rather broad ashy band or 

 belt extending over the middle of 

 the wing covers. The thorax is 

 about the same color as the ashy 

 band, but the head is more or less 

 reddish. Upon close inspection 

 it will be observed that the wins 



& 



covers are ornamented with 

 many yellowish or straw-colored 

 spots. 



The eggs, which, are always deposited in the 

 severed branches, are white, elongate oval in 

 shape, and about one-tenth of an inch in length. 



The beetles, which begin to make their appear- 

 ance in pecan orchards by the last of August or 

 early in September, have very interesting habits. 

 It is only the female of the species that cuts off 

 the twigs, but both sexes feed more or less upon 

 the tender bark and wood of the tips of the 

 branches. The branches apparently are severed 

 by the female in order that congenial conditions 

 may be provided for the development of the larvae, 

 which are unable to subsist on wood containing 

 sap, as has been determined definitely by field 

 observations. It has been observed that the 

 female in girdling does not make a complete cir- 

 cle at once, but cuts section by section until the 

 entire twig has been girdled. The girdling ex- 

 tends through the bark and well into the wood, 

 leaving only a narrow portion of the heartwood 

 untouched. (See fig. 55, c.) Usually the weight 

 of the branch, with the assistance of the wind, 

 causes it to bend down or break off. 



The egers are laid during or after the cutting 



FIG. 5-1-The hickory twig- ^ , , r -, ^i i 



girdiena, Beetle; b, larval process, but never before the beetle has cut at 

 mines in bark and outer ] eas f, one section. They are inserted singly be- 



wood; c, girdling work of i i i *- ^ 



adult. (Webb ) neath the bark, or slightly into the wood, near a 



