152 



enjoyed by the latter varieties is, however, only relative, because the 

 climatic conditions may retard the development of the midges so that 

 they appear in the greatest number when the ears of these varieties 

 make their appearance. The loss caused during years of compara- 

 tively severe infestation is estimated to equal about 5 per cent, of 

 the crop of the whole country or about £111,000. 



Tedin (Hans). Skada av Vetemygglarver pa Tvaradskorn 1916.. 



[Injury caused by the Wheat Midge on two-rowed Barley.] — 

 SvensJca Vtsadesforeningens Tidskrift, arg. xxvii, h. 1, 1917, 

 pp. 34-42. 



Injury caused by Contarinia tritici, Kirby, on two-rowed barley 

 was observed for the first time in Scania in 1912, the attack being 

 then probably spread over the greater part of the county. The 

 attack was repeated in 1913, but was then more local. Of the 42 

 different varieties of barley cultivated 21 had the ears visible on 

 the 18th of July, of the other half the ears emerged during the ] 9th- 

 27th of the same month. Of the former, 16 varieties had 10 per cent, 

 or more of the grain destroyed, whereas in the latter only 4 exhibited 

 such high percentages, the rest having far less. This is explained 

 by the fact that the midge was most numerous when the ears of the 

 earlier varieties emerged and they preferably oviposit on the newly 

 emerged ears. The average percentage of injured grain was about 8 "8, 

 equaUing a loss of about 240 lb. per acre. 



EoRER (J. B.), Cacao Spraying Experiment, 1916-1917. — Bull. Dept^ 

 Agric. Trinidad <& Tobago, Port of Spain, xvi, no. 3, 1917, 

 pp. 165-167. [Received 1st February 1918.] 



A spraying experiment undertaken to test the value of a com- 

 bination of Bordeaux mixture and nicotine sulphate as a control 

 measure for PhytophtJiora or black rot of cacao pods and for thrips 

 [Heliothrips ruhrocinchis] is here described. 



For this purpose a field previously badly infested was divided into 

 three plots, only one of which was sprayed. The solution was composed 

 of 5 lb. bluestone, 5 lb. lime to every 41 1 gals, of water, to which 

 was added 5| oz. of Black-leaf 40, and this was applied three times : 

 on 23rd August, when the trees were well covered mth young and 

 adult thrips that were ovipositing ; on 14th September, chiefly for the 

 purpose of protecting the yomig fruits from black rot ; and lastly, on 

 19th October. By the middle of November the difference between 

 the sprayed and unsprayed trees was apparent, the latter being almost 

 defoliated, while the former remained in full foliage and produced a 

 very good crop. It was proved that every spraying more than pays 

 for itself, even if the trees are only sprayed once. 



Taylor (H. W.). Tobacco Seed-beds. — Union of S. Africa Dept. 

 Agric, Pretoria, Bull. no. 7, 1917, 12 pp., 2 figs. 



The larva of the tobacco split-worm [Phthorimaea operculella] 

 attacks either the stem or leaf ; in the former case it eats out the interior, 

 causing a gall-like injury that renders the plant useless and necessi- 

 tates its being pulled up and destroyed. If the leaf is attacked, the 



