BUREAU OF ENTOMOLOGY. 315 



gained between these rather severe conditions, which correspond to a 

 sea-level latitude much farther north, and conditions at Thomasville, 

 Ga., near the Florida line. It seems probable from these studies 

 that the Mexican beatt beetle will be able to extend its range over a 

 very large part of the continental Unit€d States, Careful studies 

 have been made of the possibilities of natural control. A number of 

 new predacious enemies have been observed, but none has been effec- 

 tive. An expert is engaged in searching for parasites of the insect 

 in Old Mexico. 



Other ixsects ixjurious to reaxs and peas. — Work on the con- 

 trol of the pea aphis was continued in California, with especial at- 

 tention to cannery peas. Nicotine dust was found impracticable 

 because of unfavorable weather conditions, but spraying proved 

 satisfactory, the formula of three-fourths pint of nicotine sulphate 

 and 8 to 10 pounds of soap to 100 gallons of water being more 

 effective than the formula previously used, i. e., 1 pint nicotine sul- 

 phate and 4 pounds soap. With the use of a large, power-driven 

 outfit covering 6 rows at a time, 12 acres a day were covered, and 

 probably 18 acres a day can be reached with some improvements. 

 The total cost of spraying, using 100 gallons to the acre, was about 

 $2 per acre for material and labor. Life-history studies of the beet 

 army worm {Laphi/gma exigua) on peas show a possible maxi- 

 mum of 5 generations a year in southern California, altliough 

 ordinarily only 4 occur. Although the young worms feed inside 

 the terminal clusters under a weblike covering, making it difficult 

 to reach them with a spray, a satisfactory method of control was 

 obtained by spraying with lead arsenate, 3 pounds to 100 gallons 

 of water. Work on the bean fly or seed-corn maggot has been the 

 subject of research in New Jersey for several years past and has 

 just been completed, embracing a thorough study of the biology 

 and life history and a knowledge of its breeding habits during the 

 summer months. The bean leaf-beetle and bean aphis are also being 

 studied in different regions. 



SwEET-POTATO WEEVIL ERADICATION AND CONTROL. The SWect- 



potato Aveevil eradication campaign in Alabama, Mississippi, 

 Georgia, and Florida is continuing as heretofore, and the expected 

 progress in Baker County, Fla., and Charlton County, Ga., is being 

 made, the number of infested farms and the infestations having 

 been lowered to such a degree that the large commercial areas sur- 

 rounding are now no longer threatened. All sweet potatoes on 

 the infested properties are carefully checked and disposed of under 

 the supervision of inspectors. Although no weevils have been 

 found in Charlton County during the past year, measures are being 

 continued on all suspicious properties, and the systematic inspec- 

 tion prevalent over the entire area is being facilitated by better 

 cooperation with the growers than ever before. New projects in 

 Polk and Hillsboro Counties, Fla., based on different plans of eradi- 

 cation, are being followed. It is as y^t too early to give any 

 definite information on results. With the elimination of the wee- 

 vils from the three districts above mentioned, the State quarantine 

 forces should be able to protect the sweet -potato industries of their 

 respective States. In Alabama no weevils have been found in the 

 area formerlv known to have been infested. In Mississippi very sat- 



