69 



1902 — he had observed affected stalks in fields of tobacco thei-e, and 

 when the leaves were broken off it was found that a hole was in the 

 center, caused hy a small insect known there as "the borer,'' The 

 insect seemed to start at the root and make its way i>'radually up into 

 the heart of the stalk, its presence being indicated by the leaves 

 dropping and the stalk gradually withering and turning yellow. 



There can be no reasonable doubt that the species in question is 

 Trichobaris insoUta Case}^, a species rather commonly found in that 

 portion of Florida. 



DISTRIBUTION. 



In defining the distribution of the potato stalk weevil it has been 

 said that that species was rather generally distributed throughout 

 the Carolinian and Austroriparian regions, and that it was found 

 westward to Texas. Such a statement has previousl}^ been made by 

 Casej^ and probably others, and it may be that the insect really inhabits 

 Texas, but in a series of 34 specimens at present available Texas- 

 labeled individuals are not in evidence. 



Trichobaris iiiucorea is represented in the national collection and 

 others at present under observation by upwards of 60 individuals, 

 from which the following locality list is taken: Columbus and Willis, 

 Tex.; Los Angeles, Kern County, and elsewhere in California (no 

 definite locality) ; Tucson, Galiuro Mountains, Santa Rita Mountains, 

 Catalina Springs, and Oracle, Ariz. LeConte records the species from 

 Cape San Lucas, Lower California, and there is little doubt that it 

 occurs elsewhere in Mexico. The type specimen was found near Fort 

 Yuma, Cal. (Proc. Acad. Nat. Sciences, Phila., 1858, p. 59.) 



METHODS OF CONTROL. 



In spite of the close relationship of this species to the potato stalk 

 weevil, it is verj^ evident that we have an entirely different problem 

 to solve. The similarity of the insects is structural. The habits are 

 materially different; for whereas the potato weevil has a definite time 

 of appearance and disappearance, from April to May, and again the 

 folio sving year at the same time, we see no more of the insects until 

 after they have laid their eggs and the larv8B have transformed to 

 pupa^ and thence to adults in the stalks. Here they remain during 

 the winter. The tobacco weevil, on the contrary, evidently escapes 

 from the stalks after the tobacco leaves have been cut, and hibernates 

 in other places. 



Paris green, Mr. Shelfer has oljserved, applied as a spray by means 

 of a knapsack outfit, will kill the beetles, and he is of the opinion, in 

 which the writer concurs, that if an arsenical is used at intervals during 

 the season at the proper time, beginning with the time that plants are 

 set out, the insect may be kept under control. 



