141 



Burton-Brown (G.). The Destruction of Cockroaches. — Lancet^ 

 London, no. 4841, 10th June 1916, p. 1192. 



This note records the efficiency of Dalmatian insect powder against 

 cockroaches, contrary to Dr. Holt's experience. The powder was laid 

 down along the floor near the walls. 



^ CoPEMAN (Lieut.-Col. S.M.). Prevention of Fly-breeding in Horse- 

 (_^ Manure.— Z«nce<, London, no. 4841, 10th June 1916, pp. 1182- 



1184, 2 figs. 

 In various miUtary camps during 1915 the plague of flies, owing to 

 the proximity of horse-lines and the resultant heaps of manure, was 

 very serious, and farmers who contracted for removal were unable to 

 carry out the work with sufficient rapidity owing to shortage of labour, 

 horses and carts. Incineration was tried, but countermanded as very 

 wasteful. A borax dressing, as advocated in the U.S.A. [see this 

 Review, Ser. B, ii, p. 179], though satisfactory in smaU experimental 

 heaps, must be used in such quantity as might render the manure 

 injurious to vegetation. Hellebore, also recommended in the U.S.A., is 

 too costly [see this Review, Ser. B, iii, p. 193]. As an alternative, close 

 packing was tried combined with the use of tetra-chlor-ethane, a 

 gallon of which was poured into a depression on the upper surface of 

 the heap of 500 cubic feet. The eft'ect was tested by enclosing 12 

 maggots in each of a number of small wire-gauze boxes and burying 

 these in different parts of the heap at a depth of about 4 inches ; all 

 the maggots were killed. Similar tests in heaps without any tetra- 

 chlor-ethane gave essentially the same result. It was thus more or 

 less proved that simple close packing of the manure was all that was 

 necessary to prevent the breeding of flies. It was found that the piles 

 should not exceed 5 feet in height, and that each fresh load should be 

 firmly pressed down with shovels and in dry weather slightly sprinkled 

 with water. According to F. M. Howlett, who conducted the investi- 

 gations, the maggots are killed quickly by either a dry or wet heat of 

 115° F, and will probably not live for long at 106° F, A table is given 

 showing the time required to kill at various temperatures between 

 108°-122° F., dry and wet ; the time is very much shorter for wet than 

 for dry heat, and 12| minutes sufficed in wet heat at the lowest tempera- 

 ture, whereas no eft'ect was observed in dry. A table of temperatures 

 of the packed manure heaps is given, which shows that so much heat is 

 developed that no larvae can live in them [see this Review, Ser. B, iii, 

 p. 197 and iv, p. 22]. The ground on which the manure is to be stacked 

 should be either cemented over or prepared by mixing 1 part by volume 

 of mineral- wood-preserving oil with 40 parts of fine soil, spreading the 

 mixture on the groimd and beating it down ; 1 gallon of oil will 

 suffice for 100 square feet. Close packing does not seriously affect the 

 value of the manure. 



Hirst (S.). Notes on Parasitic Acari. — Jl. Zool. Research, London, i, 

 no. 2, June 1916, pp. 59-89, 14 figs. 



The following species of Acari occur in Britain : — Gamasidae : 

 Haemogamasus nidi, Mich., on Mustela nivalis, Ajwdemus hebridensis, 

 E'pimys norvegicus, Talpa europaea, and in the nests of Apodemus 



