316 



Severin (H. C). The Buffalo Tree Hopper, the Plum Tree Borer, 

 the Leaf Grumpier, the Plum Web-Spinning Sawfly, the Mealy 

 and Rusty Brown Plum Lice, the Plum Cureulio and the Plum 

 Gouger, and Scale Insects. — Office of State Entomologist S. Dakota, 

 Brookings, Circulars 2-8, November 1918. [Received 28th May 

 1919.] 



The bulk of the imformation contained in these circulars has already- 

 been noticed [see this Review, Ser. A. vii, p. 183.]. Chionaspis salicis- 

 nigroe, Walsh (poplar and willow scale) is one of the principal insect 

 pests of these trees in South Dakota, whether growing wild, or in parks, 

 streets, etc. When the insects are very abundant the tree may be 

 dwarfed or even killed. Remedial measures are the same as for the 

 oyster-shell scale [Lepidosaphes ulmi]. 



EwiNG (H. E.). New Acarina. PartlL — Descriptions of New Species 

 and Varieties from Iowa, Missouri, Illinois, Indiana and Ohio. — 



Bull. Amer. Museum Nat. Hist., New York, xxxvii, 1917, pp. 

 149-168, 4 plates. [Received 18th June 1919.] 



Among the mites dealt with in this paper is Eupalus parvus, sp. n., 

 a natural enemy of Lepidosaphes vlmi, L. (oyster-shell scale), from 

 which it was taken at Ames, Iowa, in which locality, however, it is not 

 very numerous. 



Elwyn (A.). Effect of Humidity on Pupal Duration and on Pupal 

 Mortality of Drosophila ampdophila, Loew. — Bull. Amer. MuseHui 

 Nat. Hist., New York, xxxvii, 1917, pp. 347-353. [Received 18th 

 June 1919.] 



The author's summary of this paper is as follows : — Changes in 

 relative humidity have no marked effect on the length of pupal period 

 of Droso])hila ampelophila. Changes in relative humidity produced 

 striking changes in the mortality of Drosophila, the mortality in- 

 creasing with a decrease of humidity and the optimum humidity being 

 100 per cent. The eiTects of low humidity on mortality are most 

 marled with very young pupae, whose covering permits a rapid 

 evaporation of body moisture. After a few hours, when integumental 

 changes making evaporation more difficult have set in, the effects of 

 low humidity are correspondingly decreased. 



Shull (A. F.). Genetic Relations of the Winged and Wingless Forms 

 to each other and to the Sexes in the kT^\ii^,Macrosiphum solanifolii. 

 —American Naturalist, Lancaster, Pa., lii, uos. 622-G23, October- 

 November 1918, pp. 507-520. 



Of Macrosiphum solanifolii there are four kinds of individuals, the 

 apterous viviparous female, which is green ; the alate viviparous female, 

 also green ; the oviparous wingless female, which is yellowish green till 

 late in life ; and the male, which is winged and of a brown or brown 

 and green colour, but pink or grey at birth. 



Experiments have shown that winged viviparous females produce 

 mostly wingless females in the parthenogenetic portion of the cycle, 

 and sexual females in the sexual portion, whereas the wingless vivi- 

 parous females produce chiefly winged females in the parthenogenetic 



