94 



author showed signs of polyhedral disease. The chief infestation was 

 at the periphery of the area ravaged in 1917. The damage was such 

 as to make it probable that a great many individuals must be immune 

 from polyhedral disease. 



Knischewskv (O.) cS: Voss (G.). Die Erdflohe. [Flea-Beetles.] — 

 Fliigblatlsaniriilii/n!^ von E. Schaffnit, Bonn-Poppelsdorf, no. 15, 

 April 1919. (Abstract in Zeitschr. Pflanzcnkr., Stuttgart, xxx, 

 no. 6-7, 1920, p. 251.) 



The appearance and habits of flea-beetles of the genera Phyllotreta 

 and Psylliodes are described. Measures against them include burning 

 all harvest debris ; the encouragement of rapid development of the 

 young plants ; very early or very late sowing ; shading and the 

 keeping damp of seed-beds by mulching with peat and watering ; 

 dusting the plants with lime, tobacco, soot, etc. ; and collection of 

 the adults on sticky racquets or boards. 



SiEGMUND ( — ). Mittel gegen Erdflohe. j Measures against Flea-Beetles.] 

 — Wiener landw. Ztg., Ixix, 1919, p. 292. (Abstract in Zeitschr. 

 Pflanzenkr., Stuttgart, xxx, no. 6-7, 1920, p. 251.) 



The seed of rape, cabbage or other vegetables should be softened by 

 soaking for a night in petroleum ; after draining, it must be mixed 

 with dry sand. Germination will not be interfered with, and the 

 young plants are immune from attack by flea-beetles. 



Landry (A.). Le grand N^mate du M61eze {Nematus erichsoni). — 

 Natur. Canad., Quebec, xlvii, no. 5, November 1920, pp. 99-112, 

 3 figs. 

 The morphology, biology and control of Lygaeonematns (Nematus) 



erichsoni (larch sawfly) are discussed, but little new information is 



The insect parasites of L. erichsoni include : — Mesoleius ienthvedinis, 

 Coclopisthia nematicida, Diglochis sp., Microcrypiuslabralis, Pteromalus 

 nematicidus, Aptesis microcincta, Spilocryptus incubitor, Coelichneumon 

 fuscipes, Cratichnetimon anmdator, Cryptus niinator, Perilampus sp., 

 Pcrilissiis filicornis and Microgaster sp. 



Decoppet (M.). Le Hanneton. — Lausanne & Geneva, Librairie Payot 

 & Cie, 1920, 130 pp., 5 figs., 41 maps, 5 tables, 5 charts, 5 plates. 



The object of this monograph is to collate the information obtained 

 as the result of many years' observations on the incidence, life-history 

 and habits of Melolontha melolontha, L., and M. hippocastani, ¥., 

 with special reference to the canton of Zurich. The natural and artificial 

 control of these cockchafers is dealt with, and a special chapter is 

 devoted to the destruction of their grubs in forest nurseries. 



The text of the legislation against these pests during 1870-1919 is 

 given verbatim, and Perris' characters for the determination of the 

 larval forms are included. 



Attention is called to various organisations in other countries, such 

 as the Imperial Bureau of Entomology, London, and the necessity 

 for a similar well-organised service for the protection of cultivated 

 plants in Switzerland is emphasised. 



An extensive bibliography is appended. 



