IMPORTAN-T PECAN IlSrSECTS AND THEIR CONTROL. 



47 



As stated before, the beetles begin to make their appearance in the 

 pecan orchards about the hist of August, and they may be found 

 continuing their girdlmg operation until cold weather. 



CONTROL MEASURES. 



For the control of this pest all that is necessary is to gather the 

 severed branches and burn them in the fall or winter. Care should 

 be exercised to collect all branches from the ground, as well as 

 those that may be lodged in the trees. By following this pro- 

 cedure all the eggs and larvae which would otherwise develop into 

 beetles the following summer will be destroyed, and thus the source 

 of infestation will be ehminated. Pecan orchards that are growing 

 adjacent to native hickory or persunmon 

 trees will be found to be worst infested, 

 because, as has been stated, this insect 

 breeds abundantly in the severed branches 

 of such trees. Under such conditions it 

 would pay, perhaps, to destroy the 

 branches cut from the hickory and per- 

 simmon trees immediately adjacent to 

 commercial plantings of pecans. 



THE OAK PRUNER.i 



During the fall and winter twigs or 

 branches pruned by the larvae or grubs 

 of the dark-brown beetle known as the 

 oak pruner (fig. 58) are to be found 

 under pecan trees, as well as under 

 oak, hickory, and various other forest, 

 shade, and fruit trees. This insect 

 does not especially favor the pecan, 

 but seems to show a preference for vari- 

 ous oaks. Although this insect occurs 

 from New England westward to Michi- 

 gan and southward to the Gulf States, it is seen too rarely in suf- 

 ficient numbers in its extreme southern distribution to be ranked as 

 a serious pest. In the North, however, serious injuries are sometimes 

 caused by its pernicious pruning habits. 



In the case of the pecan twig-girdler the twigs are cut off _ by the 

 female beetle, but with the oak pruner the larvae amputate the 

 branches by gnawing a circular groove in the wood, leaving only the 

 bark intact. The branches so amputated are usually brought to 

 the ground by the first strong wind, or, in some instances no doubt, 

 by the weight of the branch itself. The end of the severed branch 

 presents a smoothly cut surface (see fig. 58), near the center of 



Fig. SS.— The oak pruner ( Elaphidion 

 viUosum): a, Larva; 6, adult; pruned 

 twig and larval mines at right. 



Elaphidion villosum Fab. 



