193 



Strickland (E. H.) & Griddle (X.). The Beet Webworm (Loxostege 

 sticticalis, L.). — Canada Dept. Agric, Entorn. Branch, Ottawa, 

 Crop. Protection Leaflet 12, [n.d.], 3 pp.. 4 figs. [Received 8th 

 March 1920.] 



The beet webworm {Loxostege sticticalis, L.) frequently appears in 

 enormous numbers in the prairie provinces. ^Mien its food-plants 

 are destroyed it migrates in the manner of the army cutworm [Euxoa 

 agrestis], but is not destructive to grain crops. There are two genera- 

 tions in the year, the moths appearing in ]\Iay and late July. 



The larvae are rather beneficial than otherwise to field crops, as 

 they destroy all sorts of weeds, and only attack flax and lucerne 

 after all the weeds are gone, while grain crops are left alone. On 

 the other hand beet and garden plants are quickly and entirely 

 destroyed. If the larvae are about to invade some susceptible crop, 

 a deep furrow should be ploughed in their path and treated with a 

 poison bait consisting of 50 lb. of fresh weeds moistened and thoroughly 

 dusted with 1 lb. Paris green ; two furrows, a rod apart, may be 

 advisable if the webworms are very numerous. 



A spray applied at the rate of 100 gals., per acre and consisting 

 of Paris green 3 lb., lime 3 lb., water 100 gals., is very efiective on 

 infested areas. 



Mathieu (E.). Tuba-Root {Denis elliptica) as an Insecticide. — The 

 Gardens Bull., Straits Settlements, Singapore, ii, no. 6, 31st 

 January 1920, pp. 192-197. 



This paper consists of a recapitulation of some of the tests and 

 conclusions on derris in one already noticed [R.A.E., A, vii, 496]. 



In the control of the fly, Agromyza phaseoli, which has caused a 

 complete destruction of the bean crop, none of the ordinary remedial 

 measures had any success. An extract was then tried, made of 

 10 oz. of tuba-root well pounded, the juice expressed, and the fibre 

 exhausted in 20 gals, of water. This was applied to the young plants, 

 a cigarette tin full to four plants, morning and evening for 1.5 days 

 by which time the plants were sufficiently estabhshed to be safe. 

 This treatment was completely successful. 



Jack (R. W.). Tobacco Pests of Rhodesia, Part II. — Rhodesia Agric. 

 Jl.. Salisbury, xvii, no. 1, February 1920, pp. 28-33, 5 plates. 



This is a continuation of a paper recentlv noticed [R.A.E., A. viii, 

 134]. 



There are three species of Tenebrionid beetles that attack tobacco 

 after the manner of cutworms, but only newly planted crops sufier 

 appreciably. One of these, a species of Gonocephalum, is easily 

 destroyed by poisoned bait, like that used for cutworms with the 

 optional substitution of sodium arsenite for Paris green. No practical 

 method of destroying the others {Zophosis spp.) has yet been found. 



Tenebrionid larvae of the genera Psammodes and Trachynotus, 

 called wireworms in Rhodesia, cause considerable damage under- 

 gromid. Their attacks usuaUy, but not invariably, occiur on newly 



