19201 ^ ECONOMIC ZOOLOGY ENTOMOLOGY. 561 



jirticlo prt'viously iintcil (E. S. K., -13, p. 457), in which nu'thods of repression 

 are (hnilt with. 



The cowpea weevil, F. H. Tadikick and H. J. RiiiMiAun (Texas St<i. liul. 

 256 (1919), pp. 9-92, pis. 6", figs. 3). — This is a review of the present status of 

 Icnowledge of Sruchus qitadriinaculatns Fabr., together witli a detailed report 

 of Investigations conducted at the station, many of which data are presented 

 in tabular form. This is the most common species of weevil infesting cowpeas 

 in Texas, occurring in all localities where tlie cowpea is grown. The climatic 

 conditions of the State are said to l)e .specially favorable for the development of 

 this insect. All varieties of cowpeas grown in the State are subject to tlie 

 attack, no prefereiiti' being shown for any particular variety. 



" Under favorable conditions the life cycle from egg deposition to emergence 

 of the adult may Ite completed in less than 3 weelcs. The weevil is very pro- 

 lific. An average of 106 eggs has been produced by females during tlie warm 

 season. Temperature has a positive influence on the rate of oviposition and the 

 length of the various stages of the weevil. In stored seed, breeding is prac- 

 tically continuous throughout the year. Most weevils undoubtedly hibernate 

 in stored seed. Nine generations of weevils occur in a year at College Station." 



Three natural enemies of the immature stages of the weevil were found : A 

 predacious mite, a chalcidoid parasite of the larva (Bntcliohins laticeps Ash- 

 mead), and an egg parasite (Uscana semifumipcnnis Girault). "Tlie weevil, 

 however, is not sufficiently checlied by its natural enemies, and remedial and 

 artificial control measures must be employed. Proper harvesting will greatly 

 reduce' the initial infestation of the field. To prevent seed from becoming re- 

 infested, it must be stored in tiglit bins or containers. The weevil can be de- 

 stroyed in any stage by heating the infested seed to a temperature of 146° F. 

 for an exposure of l.'j minutes, which will not affect the germination of the 

 seed. Fumigation with carbon bisulphid is an effective means of destroying 

 the cowpea weevil and, used at the rate of 4 lbs. for 1,000 cu. ft. of space wirh 

 a 24-hour exposure, it will kill the in.sect in all of its stages. Fumigated and 

 ' proces.sed ' or he«ited seed is always subject to reinfestation by the weevil." 



A bibliography of 34 titles, together Avith a list of 13 references to the litera- 

 ture cited, are included. 



Boll weevil controllable by poisoning cotton, W. E. Hinds (Ala. Polytech. 

 Inst. Ext. .S'err. Virc. 38 (1920), pp. 16, fiys. 6). — This discu.ssion of control work 

 with the boll weevil by dusting cotton witii calcium arsenate includes a report 

 of demonstration control work conducted by the station entomologist in 1919. 



In 9 plats in four localities in which power dusting woi"k was completed 

 results which seemed to be reliable were obtained on 120.7S acres. The average 

 yield per acre of seed cotton on this area was 903.5 lbs., representing a gain 

 over the yield on the check areas of 247.5 lbs. per acre, or an increase of 38 per 

 cent. The total cost for treatment for the entire area was .$1,130.63, or an 

 average of .$9.30 per acre for this part of the entire dusted area. The total net 

 profit for the entire area amounted to .$2,775.79. wiiich is an average of $22.82 

 per acre net profit from, the dusting work with power macliine.s. 



In 3 hand-dusted plats witli a total of 4.7 acres, from which complete 

 records were obtained, there was an average yield of G68 lbs. per acre, or an 

 iiicrea.se of 222.3 lbs. per acre over the yield of check plats. The total gain 

 from the dusting on the 4.7 acres was 1,044.75 lbs., worth .$135.82. The total 

 cost for treating the 4.7 acres was .$44.13, leaving a total net profit for that 

 area amounting to $91.09. This is an average net profit of $19.51 per acre. 



The percentages of increase in a .'series of 9 fields ranged from G to 150 per 

 cent " In an average of the 5 highest yielding fields, the yield was 1,006 lbs. 



I 



