155 



a forest of an insect capable of injuring trees, if properly followed up, 

 may lead to valuable discoveries, as, if the insects are about, they 

 are probably ovipositing, and the egg stage in the case of the more 

 dangerous wood and bark-boring beetles is often very short, forty- 

 eight to sixty hours or even less. The contributory aids to the spread 

 of insect forest pests are discussed ; for example, the question of 

 pure or mixed woods, the former, if attacked at all, naturally pro- 

 viding more of the special host tree required in a given area and thus 

 encouraging the spread of the pest ; the proper conduct of felhng 

 operations and the rapid removal of the timber ; the effect of forest 

 fires and natural causes of injury, such as windfalls, snow-break, 

 frost, etc., the damage begun by these being only too often completed 

 by insects. The methods of preventing attack or combating an attack 

 in progress are then dealt with. Examples are given of the various 

 ways in which insect damage takes place, with the suitable remedies ; 

 in many cases these are necessarily very drastic. A brief description 

 of the general characters and classification of the Coleoptera is given, 

 and the author then proceeds to deal with individual insects in order, 

 giving under each, the habitat, the trees attacked, when known, and 

 a concise life-history, in those cases in which it can be given, and 

 descriptions of parasites. A very large proportion of the insects dealt 

 with are figured, and the index contains nearly 850 names. There 

 is also a special index of trees. The plates, particularly those illus- 

 trating the nature of damage done by the insect, are excellent, and 

 the book contains a large amount of valuable practical information. 



Smith (L. B.). Pea aphis control experiments : Preliminary Report for 



IdH.—Virginia Truck Exjit. Sta., Norfolk, Bull. no. 13, 1st Octo- 

 ber 1914, 12 pp. [Received 2nd March 1915.] 



Macrosiphum j)isi, Kalt., is one of the most destructive pests with 

 which truck-growers in Tidewater, Virginia, have to contend. The 

 present report embodies the results so far attained from experiments 

 begun in the spring of 1914. A combination of whale-oil soap, 4 lb., 

 and Black-leaf 40, 10 oz., to 50 U.S. gals. (41-6 Impl.) of water, gave the 

 best and most satisfactory spray. In no case did it injure the plants 

 and 98 per cent, of the aphids were killed on the one-half acre plot 

 where it was used, which gave a good crop. The aphids are 

 apparently more susceptible to this combination than when the insecti- 

 cides are applied separately, even if, in the latter case, larger quantities 

 are used. In order to determine the effect of sprays upon the aphids 

 at different stages of their development, plots were sprayed with the 

 three most promising formulae, and the one given above again demon- 

 strated its great superiority, for it killed 95*4 per cent, of the adults, 

 93-9 of half -grown individuals, and 98*6 per cent, of the young. Whale- 

 oil or fish-oil soap may be bought or made at home. The home-made 

 soap contains no free potash and is therefore less hkely to injure the 

 foUage. In commercial soap the water content is variable, while in 

 the home-made article, this is not the case. The following formula 

 for potash fish-oil soap has had some success : — Caustic soda, 1^ lb. ; 

 water, \\ U.S. quarts ; fish oil (warmed), 6 lb. After dissolving the 

 soda in the water, the oil is added very slowly with very thorough 



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