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Florida Bugsgist 
Official Organ of the Florida Entomological Society. 
VOL..1 AUTUMN NUMBER aN /NO.2 
September 21,1917 7. | 
| WFR O83 197 
THE SWEET POTATO ROOT WEEVIL IN FLORIDA* 
By K. E. BRaGpon Sroka 
The sweet potato root weevil (Cylas formicarius) is a little 
blue and brown beetle about a quarter of an inch in length 
and closely resembling an ant. The abdomen is of a bright shiny 
blue color, the thorax and legs are reddish brown, and the head 
and snout are black. 
- This insect infests sweet potatoes and similar plants, such as 
the morning glory. It seems to be particularly fond of the wild 
- morning glory plants which grow along the Florida coast and are 
commonly known as “‘sea beans.” The eggs are laid on the stems 
or crowns of the plants. White grubs shortly emerge from these 
and bore up into the stems or down into the roots or potatoes. 
After a certain length of time the grubs assume the pupal stage 
(still white or slightly tinged with yellow) and subsequently 
become adult beetles with their striking colors. 
Since the entire life cycle is passed within the host, and the 
adult emerges only after complete maturity, it can be readily 
seen that there is no method of applying remedies in the field 
that will reach the insect; and that, when it is once once well 
established, the crop is at its mercy. As this weevil has no 
mercy, and also has a tendency to raise a large family, it often 
happens that fifty per cent or more of the potatoes are ruined 
by the time the farmer is ready to dig them. 
However, being an industrious individual, Mr. Weevil is not 
content with having accomplished this much. The farmer may 
carefully sort out what appear to be the sound potatoes for his 
winter’s store, but all in vain. It is practically impossible to 
detect his presence in every potato, and a number that are in- 
fested are almost sure to be stored with the sound ones. When 
*A revision of a paper read before the May meeting of the Society. 
