ECONOMIC ZOOLOGY ENTOMOLOGY. 759 



Researches on the development of the egg of the univoltin silk moth, 

 C. Vaney and A. Contk (Compt. Rend. Acad. Sci. [raris], 150 {1910), No. 9, 

 pp. 553-555; abs. iti Jour. Roy. Micros. Soc. [Lotidon], 1910, No. 3, p. 305). — 

 The authors distinguish 3 periods in the development of the " univoltin " egg : 

 (1) The period of the formation of the germinative " bandelette " and the 

 vitellin elements (about 5 days) ; (2) the period of latent life without appre- 

 ciable embryonic changes (9 months) ; and (3) the period of embryonic con- 

 struction, in the course of which (about 10 days) a caterpillar is formed. 



On the jaundice parasite of Bombyx mori (Mycrosporidium polyedricum), 

 V. Marzocchi {Ann. R. Accad. Agr. Torino, 52 {1909), pp. 83-96; Arch. Par., 12 

 (1909), No. 3, pp. Ji56-J,66, fig. 1; ahs. in Bui. Inst. Pasteur, 7 {1909), No. 15, 

 pp. G-'i'i. 6-'i5). — A contribution on .1/. polyedricum from the laboratory of para- 

 sitology at the University of Torino. 



The Demerara silkworm (Jour. Bd. Agr. Brit. Guiana, 3 {1909), No. 2, pp. 

 63-67). — Wild cocoons of the Demerara silkworm {Attacus hesperus) at George- 

 town are occasionally badly parasitized. In Guiana, the old witch bird {Croto- 

 phaga major) is said sometimes to raid a tree covered with a brood of silk- 

 worms and to clear them all off in the space of a few hours. 



The butterflies and larger moths affecting forestry in Britain, B. W. 

 Adkin (Quart. Jour. Forestry, J/ (1910), No. 1, pp. 9-30). — A brief general 

 account of these enemies of forests. 



Description of some new South American Arctiadae, with notes, W. Roths- 

 child (Noritutes ZooL, 16 (1909), No. 2, pp. 26S-299) .^One hundred and 

 twenty-nine forms are described as new to science. 



Some experiments on the resistance of gipsy moth eggs to the digestive 

 fluids of birds, W. Reiff (Psyche, 17 (1910), No. 4, pp. 161-164) .—From experi-' 

 ments conducted in which foreign birds were used, it was found that gipsy moth 

 eggs can withstand the action of the digestive fluids of birds belonging to at 

 least 2 families, Turdidai and Bubonidie, without suffering any, or only slight, 

 injury. The author is also inclined to think that birds of the family Fringillidai 

 may also occasionally distribute gipsy moth eggs in spite of the negative results 

 obtained in his experiments. 



Some insects injurious to truck crops. — Biologic and economic notes on 

 the yellow-bear caterpillar, H. O. Marsh ( U. 8. Dept. Agr., Bur. Ent. Bui. 82, 

 pt. 5, pp. 59-66, fig. i).— This is a report of observations made of Diacrisia 

 (Hpilosorna) virginica in Colorado which were commenced in July, 1909. 



During the late summer and fall of that year there was a serious outbreak 

 of this pest in the upper Arkansas Valley of the State. "The larvae, or cater- 

 pillars, of the first generation developed normally on weeds along the fences and 

 irrigation ditches and caused little damage to cultivated crops, but the larvae of 

 the second generation, which began to develop about the middle of August, were 

 so numerous that the weeds were not sufficient to support them and they spread 

 to sugar beets and other crops. The sugar beets, because of the extensive acreage 

 and the large supply of food which their tender foliage offered, were more 

 severely damaged than any other crop. The larviB wei-e variously estimated to 

 have infested fiom l."t.()(j() to 2(),(KK) acres of sugar beets in the upper portion of 

 the Arkansas \'alley. Definite records from this vast acreage show that fnlly 

 1,(K)0 acres were badly defoliated." Estimates based on comparative analy.ses 

 made by the chemists at the various sugar factories indicated that there was u 

 loss in sugar content of from 1 to 3 i)er cent over the badly defoliated area. 



Biologic notes based largely on observations made at Rocky Ford, Colo., are 

 lu-esented. It is stated that by September G the infestation had become general 

 and that there was probably not a field of beets in the Rocky Ford district in 

 which larvue were not present at lea.st in small numbers. 



