664 EXPERIMENT STATION RECORD. 



from which it has been repoi'ted in tills country includes New York City, Brook- 

 Ijm. N. Y., Washington, D. C, Chicago, 111., Keokuk, Iowa, Charleston, S. C, 

 Atlantic County, N. J., Philadelphia, Pa., Arizona, and Canada. It has also 

 been recorded from Vera Cruz, Mexico, Belize, Honduras, Cuba, Hawaii, Ma- 

 deira, and Algeria. 



In experiments with carbon bisulphid and hydrocyaulc-acid gas from sodium 

 eyanld, by D. K. McMillan ; with hydrocyanic-acid gas from sodium cyanid, by 

 M. M. High ; and with carbon bisulphid, by Messrs. Popeuoe and Jones and the 

 author, it was found that the lesser grain-borer possesses less resistant power 

 to both gases than do most other stored-product insects ; that fumigations in 

 low temperatures, and especially below 50° F., are practically ineffective unless 

 an excessively large amount of bisulphid of carbon or of a cyanid be used ; and 

 that it is still more desirable that from 48 hours to 3 days be the length of 

 exposure in order to kill all insects in even tight inclosures. One experiment 

 showed that even with 10 lbs. of bisulphid of carbon to 1,000 cu. ft. of space in 

 a tight receptacle only a very small percentage of grain insects were killed in 

 an exposure of 24 hours and with a temperature of about 48° F., and another 

 that even with 20 lbs. of carbon bisulphid to 1,000 cu. ft., or 10 times what may 

 now be accepted as a standard, only 75 per cent of the insects present were 

 destroyed in a 24-hour exposure. 



The author concludes that it may be safely assumed that under ordinary con- 

 ditions, in temperatures between 65 and 75° F., 14 lbs. of bisulphid of carbon 

 to 1,000 cu. ft. of air space is insufficient even for 48 hours' exposure, and that 

 as a general standard 2 lbs. to 1,000 cu. ft. for 48 hours or more, or until the 

 odor of the gas has become entirely dissipated, may be adopted. 



A bibliography of 21 titles is appended. 



The larger grain-horer {Dinoderus truncatus) (pp. 48-52). — So far as the 

 author knows, this species has never found permanent lodgment in the United 

 States, but is apt to be introduced into tropical Texas as well as elsewhere. It 

 is tropical, and though a general feeder, at least in its adult stage, is by virtue 

 of its large size apparently restricted in cereals to maize. 



This beetle was first described in 1878 from specimens accidentally found in 

 California. It was also accidentally brought to this country with corn for 

 exhibition in the Mexican section of the New Orleans Exposition in 1885, and 

 in 1893 specimens were obtained in corn and edible roots from the Mexican and 

 Guatemalan exhibits at the World's Columbian Exposition, at Chicago. It has 

 since been received in stored corn from Tlaxiaco, State of Oaxaca, and from 

 Parral, Province of Chihuahua, Mexico. 



The author finds that the pupal stage varies from about 44 days in the very 

 hottest weather to 6 days in a little cooler weather during June and July, while 

 in October the pupal period lasted 12 days, from October 17 to 29. The entire 

 life cycle from the placing of beetles in corn until the issuance of the new gen- 

 eration occupied 45 days, from August 25 to October 9. 



A bibliography of 5 titles is included. 



The bulb mite, F. Windle {Jour. Econ. Ent., 4 {1911), No. 1, pp. 127, 128).— 

 The bulb mite Rhizoglyphus hyawmthi {echinopus) , also known as the " Eucharis 

 Mite," has been found to be the source of considerable injury to bulbs imported 

 from France, Holland, and Japan. 



The taxonomic value of the microsoopic structure of the stigmal plates in 

 the tick genus Dermacentor, C. W. Stiles {Pub. Health and Mar. Hosp. Serv. 

 V. S., Hyg. Lab. Bui. 62, 1910, pp. 72, pis. 43, fig. i).— Eleven species of Derma- 

 centor are considered, 2 being described for the first time. 



The sugar-cane insects of Hawaii, D. L. Van Dine {U. 8. Dept. Agr., Bur. 

 Ent. Bui. 93, pp. 5Jf, pls. 4, figs. 5). — In this bulletin the author has brought 



