Packard] 



rsrsECTS of the forest. 



253 



another at their base. It is an inch in length, and is a com- 

 mon inhabitant of the hickory and wahiut. 



The locust tree borer also infests the hickory, and it is a 

 curious fact that while the individuals which live in the 

 locust tree appear as beetles in September, those which 

 come from the hickory, though not differing specifically, 

 appear in June, three months earlier. 



The hickory girdler (Oncideres cingulatus,* Fig. 194) par- 

 tially repeats in its singular habits those of the oak pruner. 

 I will not attempt to condense Professor Haldeman's account 

 of this insect, simply begging to differ from 

 the writer's belief that the habit, unusual as 

 it is, could never have been acquired. Until 

 we know more of the habits of these Oncidc- 

 res, and there are a number of other species 

 of this and closely allied beetles in Central 

 and South America, we are hardly in a posi- 

 tion to deny but that there may be other spe- 

 cies with quite similar habits, which in their 

 turn may be related to still other forms which 

 may exhibit traits intermediate between the 

 girdler and the average longicorn beetle. It 

 is only by comparing the intellectual acts of 

 a long series* of closely allied species that 

 we shall be able to ascertain what is excej^tional, and pos- 

 sibly be able to get a glimpse at the origin of such excep- 

 tional habits. It is for this reason that the study of the 

 habits of our common, noxious insects will have a double 

 value, an economic one and a philosophical one. They are 

 so numerous that we can never be at a loss for material on 

 which to make our observations and experiments. 



"In our walks through the forests our attention was fre- 



Tlie Gh-fller. 



*By a mistake, owing to the slipping of tlic bark after drying from each side 

 of the notcli,the incision is wrongly represented; the cut should be represented 

 as somewhat scjuare in outline, 



29 



