BUREAU OF ENTOMOLOGY. 395 



The southern corn stalk-borer. — This insect, which is closely re- 

 lated to the larger corn stalk-borer and the sugar-cane moth borer of 

 the Southeastern and Southern States, has become increasingly injuri- 

 ous and abundant during the past two years throughout the Big Bend 

 country of Texas and the river valleys of eastern New Mexico. In- 

 vestigations have shown that the counties of El Paso, Culberson, Jeff 

 Davis, Presidio, and Brewster, in Texas, are most seriously involved. 

 The pest has been reported as so abundant and destructive in the 

 Pecos Valley as to cause the growing of corn to be practically dis- 

 continued there. The species apparently is of tropical origin, but 

 has been found to occur at elevations exceeding 5,000 feet. The east- 

 ern edge of the infestation in northwestern Texas is separated from 

 the western border of the corn-growing area of the State by a strip 

 of land about 25 miles wide, in which no farming is done. As this 

 species evidently is a highland form and similar in that respect to 

 the Colorado potato beetle and the Mexican bean beetle, it seems 

 altogether possible that it has potentialities for damage throughout 

 the Corn Belt which may prove formidable, should it migrate to that 

 region. A close study of the species, therefore, is being made. 



Wheat strawworm. — The wheat strawworm is distributed 

 throughout the wheat-growing regions of the United States, and 

 ranks high in importance as an insect enemy of wheat, often destroy- 

 ing whole fields of this crop, especially in the spring wheat region. 

 As a result of studies carried on during the past few years, with 

 Charlottesville, Va., as a center, it has become possible to publish 

 during the past few months a brief Farmers' Bulletin, No. 1323, 

 w^hich affords practical information regarding the control of the 

 pest. 



Other insects. — A number of other projects are under way. The 

 corn earworm, which is the same insect as the cotton bollworm and 

 the tomato fruitworm, is from the fact of its many food plants a 

 most difficult insect to control. Possibilities of cultural methods are 

 being studied under this section and a cultural means of control dis- 

 covered has proved satisfactory in the Atlantic coastal plain region. 

 The webworms, which normally inhabit grasslands, frequently 

 damage corn to a serious extent when grasslands are broken up and 

 planted to corn. Studies of these insects have been continued with 

 measurable success in the region of which Knoxville, Tenn., is the 

 center. 



STORED-PRODUCT INSECT INVESTIGATIONS. 



Investigations in this section of the bureau work have continued 

 under the leadership of Dr. E. A. Back. 



Bean weevil investigations. — The biological studies of the bean 

 weevils, Bruchus obtectus and Bnichus quadrimacidatus, which have 

 had the leading place in the investigation w-ork being conducted 

 with headquarters at Alhambra, Calif., have been subordinated dur- 

 ino- the past year to a study of these pests in the commercial bean 

 fiekls of California. Studies of the varietal susceptibility of the 

 commercial bean varieties have been continued along with a more 

 intensive studv of the possibility of controlling field infestations by 

 the proper timing of planting and harvesting and the intelligent 

 use of trap crops. 



