256 ANNUAL PiEPOPiTS OF DErARTMENT OF AGPJCULTURE. 



cooperation -with the Florida State Plant Board. This materially 

 aids in the eradication of the weevil -without interfering Avith the 

 production of potatoes, since the contracts provide for clean culture 

 and a fallow period of six weeks prior to planting, together with other 

 repressive measures. It is believed that as the result of this work 

 the end of the growing season will find this locality practicalh^, if not 

 completely, weevil free. 



In Alabama, the infestation was fouud to be confined to a single 

 well-defined locality in Baldwin County, and excellent cooperation 

 has been secured with growers toward the application of all necessary 

 repressive measures. It is believed that this isolated outbreak will be 

 cFitirely cleaned u]^ in another season. 



In Mississippi the passage of a drastic crop-pest law materially 

 aided in the eradication measures, the establishment of a quarantine 

 rendering complete control of intercounty shipments possible. The 

 comparatively light infestation in this State has been mapped, and 

 a material reduction of the area infested has been secured. 



In Louisiana survey Avork has been continued, and groAvers have 

 been visited and urged to apply methods devised by the bureau. 

 Eeinspection recently indicates that gratif^'ing results have been 

 reached in the majority of cases. A careful study has been made in 

 this State as Avell as in Mississippi of the other food plants of the 

 morning-glorv group, especially the large-rooted perennial morning- 

 glories, and a number of chemicals have been tested as weed killers, 

 to be used against these Avild food plants. 



In Texas, 85 counties have been found infested with the weevil, 

 which has 1)een distributed apparently largely through connnercial 

 groAvers of slips shipping from the Gulf and south-central portions of 

 the State. There is no hiAv in Texas controlling the shipu.ient of 

 infested plant material, AAhich is a serious drawback to the control 

 of the Aveevil in that State. The fact that salable SAA-eet potatoes can 

 not be produced in some of the coast counties has helped the Avide- 

 spread distribution of the Aveevil, as draAvs groAAii from unsalable 

 stock often prove more profitable than the groAving of tubers. Life- 

 Jiistory studies at Kingsville, Tex., shoAved at least six generations of 

 the Aveevjls annually, indicating an enormous rate of increase.' 

 Spraying experiments at this point have reduced infestation from 

 4 1.51 per cent to from 2.88 to 12.18 per cent. 



INSECTS AFFECTING POTATO. TOMATO, AND ALLIED CROPS. 



The potato aphis, an unexpected pest which made its appearance 

 in 1917 and again in the early sunnner of 1918. Avas experimented 

 Avith on into July, 1919. The use of nicotine sprays at increased 

 strengths demonstrated practical control in oVlaryland, Xcav Jersey, 

 and Maine. 



The spinach aphis, Avhich has during recent years become trouble- 

 some as a potato pest, and Avhich also affects cabbage, beets, lettuce, 

 and other staple vegetable crops over a still wider lange of territory, 

 has been the subject of continued investigations along the Atlantic 

 coast. A ncAv station in the Aroostook region in jNfaine. a great 

 potato center, has been established for the study of the Colorado 

 potato beetle, the potato flea-beetle, and other potato pests. An in- 

 vestigation of the spread of the Colorado potato beetle on the Pacific 



