BUREAU OF ENTOMOLOGY. 241 



SWEET-POTATO WEEVIL ERADICATION AND CONTROL. 



Following an urgent request, an emergenc}- fund of $30,000 was 

 made available about March 1 for an investigation of the sweet- 

 potato weevil in the States of Florida, Georgia, Alabama, Missis- 

 sippi, Louisiana, and Texas, which might lead to its eradication and 

 control. This has made possible a preliminary farm-to-farm survey 

 of all outlying infested territory, definitely establishing the boun- 

 daries of infestation, A series of large-scale experiments in control 

 have been undertaken at field stations in Texas, Mississippi, and 

 Florida, and demonstration eradication projects have been initiated 

 in portions of Florida, Georgia, Mississippi, and Alabama, the close 

 survey accomplished having established the feasibility ox operations 

 for that purpose. 



An educational campaign by inspectors has already been produc- 

 tive of much benefit and has reduced materially the number of in- 

 fested farms in Georgia, Alabama, and Mississippi; indeed, it seems 

 probable that the completion of another season's work may find the 

 sweet-potato crop of the least infested of these States nearly weevil 

 free. 



Experiments with heat curing of sweet potatoes have shown the 

 possibility of securing a mortality of 95 per cent of weevils in storage 

 houses by carrying the tubers at a temperature of 115° F. for eight 

 days. In badly infested districts in Texas, where weevil injury is 

 frequently 50 per cent, losses have been reduced to less than 10 per 

 cent by the timely application of arsenical sprays. 



Life-history investigations have brought forward many interest- 

 ing facts regarding this weevil which can be applied the coming 

 season to excellent advantage. Good progress has been made in a 

 survey of the wild food plants of the pest. On the whole, the begin- 

 ning of the fiscal year 1919 finds the bureau well equipped to conduct 

 a most effective campaign against this pest during the coming season. 



OTHER INSECTS OF POTATO, TOMATO. AND ALLIED PLANTS. 



The potato aphis, which was an unexpected pest in 1917, reappeared 

 m still greater numbers in many regions in the early summer of 1918. 

 It attacked both tomato and potato, and occurred along the Atlantic 

 coast from Maryland and Virginia to New England and to a lesser 

 extent westward to Ohio, Indiana, Illinois, Michigan, and Wiscon- 

 sin. In Maryland it was controlled by nicotine sulphate used at 

 double the strength generally advised for plant-lice. This doubling 

 was necessitated by the greater resistance of the pest and by the unwill- 

 ingness of the farmers to make a second spraying, on account of the 

 scarcity of labor and appropriate spraying machinery. A still larger 

 dosage, namely, one-half pint of nicotine sulphate to 50 gallons of 

 water, was found desirable in New Jersey and Massachusetts. 



The spinach aphis caused considerable loss to potato, tomato, cab- 

 bage, turnip, radish, beets, lettuce, and other truck crops. It covered 

 practically the same territory and succumbed to the same remedies. 



The potato flea-beetle, the three-lined potato beetle, and the potato 

 fruitworm, as well as the common stalk-borer, were numerous and 

 received careful consideration. 



