519 



insects to their environment ; but few of the details to be found in various 

 other, larger, and more or less encyclopaedic treatises are included, 

 and matters not directly necessary for a brief consideration of insects 

 as they affect human welfare are avoided. 



The broader questions relating to food-habits, distribution, and 

 both natural and artificial control of agricultural pests are discussed 

 under the heading " Insects and the Food Supply," and a chapter on 

 " Forest Insects " emphasises the difference between problems en- 

 countered under forest conditions and those in dealing with pests of 

 herbaceous plants. Stress is laid on the necessity for discovering in 

 as great detail as possible the life-history and economic relations 

 of a vast series of insects, in order to prevent the misapplication of 

 control measures. 



In calling attention to the rapid spread over North America of the 

 European cabbage butterfly {Pieris rapae) and the fact that it has 

 largely replaced the native species, a curious error occurs in the 

 illustration on page 44. The American species figured as Pontia 

 pJiilodice is Colias philodice, whereas the insect intended is Pieris 

 {Pontia) protodice. 



The biological method of reducing the numbers of noxious insects 

 offers, at present, the most promising field in which to speculate 

 concerning the future development of entomological practice, to which 

 the concluding chapter is devoted. 



Desoil (P.). Note zoologique sur la Larve d'Aitthrenus museorum, 

 L., a propos de ses Degats dans les Magasins de Laine de Roubaix. — 



C. R. Soc. Biol., Paris, Ixxxv, no. 27, 23rd July 1921, pp. 508-510. 



The larvae of Anthrenus museorum, L., here described, do serious 

 injury to wool and the bobbins on which it is wound in a wool factory 

 at Roubaix. Only pure wool is attacked, never cotton or mixtures of 

 wool and cotton. Apparently the best quality and that of white colour 

 is preferred. During the German occupation the building was used to 

 shelter horses and their harness and camp equipment, and it is probable 

 that the building became infested with this beetle in consequence. 



Taillefert (A.). Les Larves " Fils de Fer " et les Moyens de les 

 combattre dans les Champs de Cereales. [Remedial Measures 

 against Wireworms in Cereal Crops.] — La Terre Vaudoise, 

 Lausanne, xiii, no. 32, 6th August 1921,' pp. 343-345, 1 fig. 



Wireworms were more than usually destructive to autumn-sown 

 cereal crops in Switzerland in the spring of 1921, and it is suggested 

 that land found to be infested should be well rolled until the 

 soil is compact and prevents the larvae from moving easily. The 

 ground should then have a top-dressing of 704 to 880 lb. of kainit per 

 acre, mixed with 264 to 440 lb. of quicklime. A greater quantity than 

 this is apt to injure the crop. The use of the lime is almost entirely 

 for the sake of preventing the formation of crusts on the surface of 

 the ground, due to the use of potassium salts. Where crops are already 

 seriously injured the use of sodium nitrate with the kainit is recom- 

 mended ; this does not injure the wireworms, but strengthens the 

 young plants that have not been attacked. Diluted liquid manure 

 can be substituted for the sodium nitrate, if used strong. 



Other methods that are frequently advocated include deep ploughing 

 in autumn and collection of the larvae behind the plough. In extreme 

 cases white mustard can be used as an alternative crop. 



