207 



• 



lucerne, clover, Cape dandelion, beans, potatoes and other plants. 

 As it is a gnawing insect, it may be destroyed with arsenical sprays, 

 but contact sprays are of httle use owing to its highly polished body. 



Sanders (G. E.). Spraying vs. Dusting in Annapolis Valley. — 



Canad. Horticulturist & Beekeeper, Toronto, Ont., xxviii, no. 2, 

 February 1920, pp. 27-28, 1 fig. 



It is not often recognised that spraying results in the production of 

 larger fruit, as the leaves, being kept free from fungus, are able to 

 take in more carbon dioxide from the air. The use of hme-sulphur, 

 however, tends to injure the chlorophyll, -and so may lessen the 

 food-gathering power of the leaf, while it undoubtedly sometimes 

 causes a serious dropping of the fruit. 



Dusting with sulphur has beeen tried during 1919 with remarkably 

 good results, the dust being composed of 90 per cent; sulphur and 

 10 per cent, lead arsenate. Copper-lime- arsenate dust has as yet 

 hardly been tested, but in 1920 tests are to be made on apple-trees 

 with 10 lb. dehydrated copper sulphate, 5 lb. calcium arsenate and 

 85 lb. hydrated lime. It is estimated that spraying with this 

 material will cost from 24s. to 32s. per acre less than liquid spraying 

 or dusting with sulphur only. As the dust is less adhesive than liquids, 

 five apphcations would probably be preferable to four. It is probable 

 that changes will still be made in the dusting formula and it is hoped 

 to improve upon the present mixture and make it cheaper. 



Jack (R. W.). Tobacco Pests of Rhodesia. — Dep. Agric. Salisbury, 

 Rhodesia, Bull. 347. February 1920, 15 pp., 10 plates. 



The information contained in this bulletin has been noticed else- 

 where [R.A.E., A, viii, 134, 193.] 



Phillips (W. J.). Studies on the Life History and Habits of the 

 Jointworm Flies of the Genus Harmolita (Isosoma) with Recom- 

 mendations for Control. — U.S. Dep. Agric. Washington D.C., 

 Bull. no. 808. 24th February 1920, 27 pp., 6 plates, 8 figs. 



The Chalcids of the genus Harmolita are dealt with in this bulletin in 

 three groups, viz : — Species infesting grain crops, cultivated grasses 

 and wild grasses. Under the first heading the life-histories are given 

 of H. tritici, H. grandis and H. vaginicola, infesting wheat, H. hordei 

 infesting barley, and H. secalis and H. websteri, infesting rye (this being 

 the order of their economic importance) ; under the second heading of 

 H. rdbomaculata, H. dactylicola, H. captiva, H. poae and H. festucae ; 

 while there are ten species that come under the third heading. Of 

 six more species the biology is unknown. [See also R.A.E., A, vii, 470. ) 



These insects are largely controlled by parasites, and for this reason 

 those of them that feed on wild grasses must be regarded as beneficial 

 in that they act as hosts for the parasites at times when the numbers 

 of the harmful species are low. 



The economic damage chiefly occurs in wheat, which pays a regular 

 toll every year in all the wheat producing States east of the Mississippi 

 River and in a large part of Missouri. 



