62 MISCELLANEOUS RESULTS OF WORK OF BUREAU IX. 



In the course of such work many old cornstalks were dragged out of 

 the dirt that had been thrown over them by means of a " middle- 

 buster" plow used for breaking the ground during November and 

 December; and in two or three instances, which he remembered as 

 having occurred in February, he found stalks with boll weevils 

 secreted in the cavities evidently formed by the stalk pests. 



At the time of my first examination the emergence holes and other 

 signs of work by Ar secerns fasciculatus were not visible unless the 

 leaves were stripped from the stalks as they stood in the fields. 

 Centers of infestation were then located in different parts of the 

 fields by breaking open a number of stalks to ascertain the extent of 

 depredations. As most of the ears had been gathered, inspection of 

 the greater part of the fields was freely made and infested sections of 

 the stalks were collected. The damaged stalks broke easily at the 

 joints where larvae had worked, and usually but one injured place 

 was found on a stalk. All attacks by the weevils at this time were 



Fig. 18.— Coffee-bean weevil (Arsecerus fasciculatus): a, Larva; b, adult or beetle; c, pupa. Greatly 

 enlarged. (From Chittenden.) 



confined to the upper joints. These damaged joints varied in thick- 

 ness from a little more than an inch to slightly less than one-half 

 inch. The extra thick and hard structure of the lower joints was then 

 thought to present unsuitable conditions for the breeding of the 

 weevils, at least where the pith incompletely filled the stem. Further 

 developments which were noted on my second examination showed, 

 however, that the insects had bred extensively and worked down- 

 ward into the lowest joints, their tunnels running through the pith 

 from one joint to another. Since all stages were found again, the 

 prospect for continual breeding of the weevils, which perhaps depends 

 upon mild weather, seemed to be assured as long as the stalks were 

 not destroyed. As previously observed, the effects of their work 

 were most noticeable at the joints. The common occurrence of 

 damaged stalks, which were readily detected on account of the emer- 

 gence holes being exposed to view by reason of the partial loss of the 

 leaves, indicated that the infestation was widespread. 



