170 



Leach (B. R). U.S. Bur. Ent. A Study oJ the Behaviour of Carbon 

 Disulfide when injected into the Soil and its Value as a Control 

 for the Root-form of the Woolly Apple Aphis. — Soil Science, 

 Xeio Brunsivick, A'. Y ., x, no. 6, December 1920, pp. 421-452. 

 2 plates, 8 figs. 



The methods adopted during these investigations are described. 

 The amount of injury caused to apple trees by the employment of a 

 dose sufficient to rid them of woolly aphis [Eriosoma lanigerum] 

 prohibits the use of carbon bisulphide as a remedy for this pest. The 

 degree of injury to the roots depends on the diffusion of the gas in the 

 soil, but the indirect effect of root injury upon the rest of the tree 

 varies considerably with the season and consequent stage of seasonal 

 growth, and is apparently due to the interference with normal 

 transpiration. " 



Roebuck (A.). Frit Fly {Oscinis frit) in relation to Blindness in 

 Oats. — Ann. A pp. Biol., Cambridge, vii, no. 2-3, December 1920, 

 pp. 178-182, 1 plate. 



As a result of observations made during the summer of 1919, 

 three broods of Oscinella (Oscinis) frit are thought to occur on oats. 

 A certain percentage of the intermediate brood is directty connected 

 with blindness of spikelets. From the end of June to end of July 

 larvae were found anywhere amongst the curled-up mass of the panicle, 

 protected from the outside by the enclosing leaf and destroying the 

 enclosed flowers. In some cases only the central axis and branches 

 were left, and these presented a blanched and twisted appearance 

 on unfurling. During 1917 this brood was also found in abundance 

 on stems of winter wheat. 



Jacksox D. J.). Bionomics of Weevils of the Genus Sitones injurious 

 to Leguminous Crops in Britain. — Ann. App. Biol., Cambridge, 

 vii, no. 2-3, December 1920, pp. 269-298, 6 plates, 6 figs. 



Sitones lineatus, L., of which all stages are here described, is wideh' 

 distributed throughout Europe. The observations of pre\'io\is authors, 

 both in England and elsewhere, are reviewed. This weevil is common 

 throughout the British Isles, but is most destructive in the South of 

 England. The present field observations were made at Wye, Kent, 

 and in Ross-shire. Peas and beans are the favourite food-plants, 

 and clo^^er is apparently only attacked when other food-plants are 

 not available, but the species may also be found on lucerne throughout 

 the year. The most serious damage to beans and peas is caused by 

 the adults in the spring when they emerge from hibernation. During 

 the winter they may be found sheltering in long grass. The date 

 of appearance in spring varies according to the season and the latitude 

 — from 27th March in 1918 in Kent to the middle of May in Scotland 

 in 1919. They feed principally on young unopened leaves of the 

 terminal shoots of beans until the plant is ready for cutting, but 

 the terminal shoots of peas are only attacked while the plant is small ; 

 when over a foot high the leaves near the ground are eaten. The 

 hibernating individuals may survive until July or beginning of August ; 

 in Ross-shire a few were collected in September, but they have not 

 been observed to live through a second winter, the length of life being 



