487 



acid and then sufficient water to make 2 quarts. This should be used 

 in the strength 1 pint of stock to 6 U.S. gals, water. Poison-baits for 

 the ants have not proved satisfactory. Caterpillars of Papilio androgens, 

 Cram., and of Eanlis thraso, Hbn., have been fairly numerous, but 

 neither species caused appreciable damage. 



It is pointed out that the failure in many cases to obtain a good 

 oil-emulsion has been entirely due to the kind of soap used. Owing 

 to scarcity of potash the composition of the common commercial 

 soaps has been changed and these are apt to solidify in an emulsion 

 within a few hours, rendering the spray worthless. As a result of 

 experiments it has been found that an excellent emulsion can be made 

 with ordinary hard, fish-oil soap, that will remain a good liquid for 

 several days, by the following method :— Eight pounds of octagon 

 or fish-oil soap are dissolved in 2 U.S. gals, water by heating ; while 

 still hot, 2 U.S. gals. Corvus oil should be slowly stirred in so that a 

 good emulsion is obtained ; I lb. ordinary cooking flour is then stirred 

 in, 4 U.S. gals, water are added and the whole mixture heated again 

 until it boils. After removing from the lire, one quart of crude carbolic 

 acid is added and the solution is then ready for use. For spraying, 

 this stock should be diluted at the rate of 1 part to 25 of water. 



TuRNEE (W. B.). Female Lepidoptera at Light Traps. — Jl. Agric. 

 Research, Washington, D.C., xiv, no. 3, 15th July 1918, 

 pp. 135-149. [Received 10th September 1918.] 



As a test of the generally accepted theory that in the case of 

 Lepidoptera taken at light-traps practically all individuals captured 

 are males and that the few females taken have all previously oviposited, 

 the author conducted a series of observations at Maryland during 

 1916. 



A brief account is given of the methods employed to obtain material 

 and a summary of the facts deduced from examination of the results. 

 A table shows the percentages of the males captured including the 

 following species : Apantesis vitlatu, F., 98 ; A. arge, Drury, 82 ; 

 Esiigmene acraea, Drury, 85 ; Diacrisia virginica, F., 88 ; Isia Isabella, 

 A. & S., 86; Halisidofa (essellaris, A. & S., 70; Datana ministra, 

 Drury, 71 ; Phytometra {Aiitojrapha) bihba, Stephens, 95 ; P. (A.) 

 simplex, Gn., 76 ; Meliana diffusa, Wlk., 89 ; Polia renigera, 

 Stephens, 71 ; Caenurgia erechtea, Cr., 64 ; C. crassiuscala, Haw., 

 64^; Cirphis unipuncta, Haw., 56| ; Agrotis (Noctua) c-nignim, L., 

 47 ; and Feltia spp., probably including F. siibgothica. Haw., F. annexa, 

 F. gladiaria, Morr., and F. jactdifera, Gn., 72. Of 11,222 moths 

 examined, llh per cent, were males ; only in one species, Agrotis 

 c-nigrnm, did the females equal or exceed the males. Of a total 

 of 3,197 females captured, 58 per cent, were gravid, or 16'6 per cent, 

 of the total number of moths examined. A great deal of information 

 has also been gathered from various records of other observers upon 

 this question ; this is summarised in a table showing that out of 

 28,094 individuals, males constituted 55 per cent, and females 45 per 

 cent. 



If it be assumed that the sexes exist in nature in approximately 

 equal numbers, the investigations on which this paper is based are 



