529 



that Diabrotica vitiata retains the organism of cucurbit wilt in a viable 

 condition for at least six weeks when the insect is placed in cold storage. 

 Attempts to recover the spores of late blight from hibernated indivi- 

 duals of L. decemlineata have not as yet been successful. 



A consideration of these facts makes it evident that many fungous 

 diseases can be more effectively controlled by insecticides than by 

 fungicides. For example, young apple seedlings in one nursery that 

 were constantly dipped in kerosene emulsion and thus kept free 

 from Aphids were free from blight disease, while in surrounding nurseries 

 it was very prevalent. 



LocHHEAD (W.). Some Common Things on the Farm. — 11th Ann. 



Kept. Quebec Soc. Prot. Plants from Insects and Fungous Diseases, 

 1918-1919; Quebec, 1919, pp. 66-71, 9 figs. [Received J ith 

 October 1919.] 



This paper is a synopsis of an illustrated address given to teachers, 

 children and parents, dealing with the more common insect pests, 

 fungous diseases, weeds, etc. 



Dendy (A.) & Elkington (H. D.). On the Prevention of Heating in 

 Wheat by Means of Air-tight Storage. — Kept. Grain Pests (War) 

 Committee, Royal Society, London, no. 5, July 1919, 10 pp., 2 figs. 

 [Received 15th October 1919.] 



With reference to the efficacy of airtight storage for dealing with 

 infested grain [see this Review, Ser. A, vii, p. 94] the possibility of the 

 process known as '' heating " under these circumstances has been the 

 object of recent experiments. Previous literature on the same subject 

 is reviewed. 



These observations show that not only does " heating " not take 

 place under airtight conditions, but this treatment also prevents the 

 growth of moulds, even in the presence of excess of moisture. The 

 experiments were carried out on small quantities in thermos flasks, and 

 owing to the purposely exaggerated moisture the wheat became acid. 

 This may impair its milling value, but there are no grounds for believing 

 that this acidity could develop in normally dry wheat under similar 

 conditions. The limit of safety as regards moisture for wheat intended 

 for prolonged treatment requires further investigation on a larger scale. 

 The temperature charts given present two distinct maxima, suggesting 

 the presence of two distinct processes of fermentation. The first is due 

 to enzymes in the grain itself, whilst the second may be due to microbic 

 fermentation resulting in the rotting of the wheat. 



Deslandes (E. a.). Entomologia para Uso das Escolas Agricolas do 



Brazil. — Lairas, Minas, 1919, 2nd edition, 66 pp. 



This little book aims at giving elementary instruction in entomology. 

 The first part deals with the anatomy and physiology of insects, and 

 the second with taxonomy. The collection and destruction of 

 injurious insects is the subject of a special chapter. 



