464 EXPERIMENT STATION RECORD. 



more important insect enemies of the grape in France and other European 

 countries. 



Combating the wood-boring' caterpillars of Zeuzera pyrina in cork-oak 

 forests, P. Lesne {Compt. Rend. Acad. Sci. [Parits], 152 (1911), No. 19, pp. 

 1269-1271). — In continuing work with this pest (E. S. R., 20, p. 354) the 

 author in applying carbon bisulphid has made use of long slender gelatine 

 capsules that can be readily introduced into the galleries. Experience has 

 shown that 24 hours is a sufficient period of time for the capsule to be dis- 

 solved by the moisture present in the galleries and the larvre destroyed. 



The injury to sugar beets by the Wintersaateule (Agrotis sp.) and 

 methods of combating it, Wassiliew (Bl. ZackorilhenMu, 17 {1910), No. 

 80, pp. S30-332; abs. in Internat. Inst. Agr. [Rome], Bui. Bur. Agr. Intel, and 

 Plant Diseases, 1910, No. 2, p. 379). — Agrotis larvie are said to be the source 

 of considerable injury to sugar beets in the Government of Kiew, Russia ; they 

 first consume the leaves and later the other parts of the plant. 



Report of mosquito work for 1909, J. B. Smith {Ne^v Jersey Stas. Rpt. 

 1909, pp. 421-Ji59, figs. S).— During the year 360,800 ft. of ditching were dug 

 and 2,672 acres drained, making a total of 3,464,974 ft. of ditching dug and 

 25,192 acres drained to date. 



Brief mention is made of bats as enemies of mosquitoes and of an investiga- 

 tion made of the water plant {Azolla sp.), previously noted (E. S. R., 24, p, 

 562). Experiments conducted with iron sulphate and Culex pipiens larvae 

 show that at the rate of 1 oz. to 1 gal. of water this material is a good, and 

 at double that rate, an effective destroyer of mosquito larvae and pupse. Under 

 some circumstances it may be useful on a limited scale, but it will do nothing 

 tkat petroleum will not do at much less expense. 



The author finds that a concentrated extract like NIco-fume is an exceed- 

 ingly violent larvacide, and at the rate of 1 part to 2,500 of water will kill all 

 larvae of C. pipiens. In experiments with Hyco it was found that at a dilution 

 of 1 to 30,000 it can be relied upon to kill all larvae, except, perhaps, those just 

 ready to pupate, but that 1 to 10,000 is the extreme limit ©f dilution effective 

 against pupae and that, even here, adults would probably emerge safely from 

 pupae just ready to transform. Under natural conditions no lasting results 

 follow on the treated area, and within a day or 2 after the application the 

 water is again safe for mosquito development. 



A systematic fumigation of cellars in Newark and vicinity where mosquitoes 

 hibernate in immense numbers, thousands in a single cellar in some instanceis, 

 was discontinued after a few days, as the results were not as satisfactoiy as 

 was expected. A chemical analysis of the stramonium used showed that the 

 alkaloidal content of the drug varies greatly. When the material is stored, 

 imless it is kept in very tight receptacles, it loses in strength and may in time 

 become almost inert. The alkaloidal content of 6 samples of stramonium from 

 as many different sources was found fo be ©.32, 0.24, 0.15, 0.24, 0.02, and 0.12 

 per cent, respectively. The first, second, and fourth mentioned represent fresh, 

 full-strength material; the third, fifth, and sixth represent the run of the 

 market, ranging from fair to almost inert, the fifth being of little more value 

 than so much dried hay. 



The details of inspections made along the shore and in the vicinity of various 

 cities follow. Notes of the Season, by J. A. Grossbeck (pp. 457^59), are ap- 

 pended to the report. The author finds that where natural breeding places 

 are scarce, it is quite possible to attract C. pipiens for a considerable distance 

 around to an artificial area where they can be kept under observation and 

 control. " It seems indicated, also, that when such an attractive place is pro- 

 vided, the insects do not so readily bite or frequent even near-by dwellings. 



