137 



Capus (J.). L'Effeuillage. Moyen de Defense contre les Parasites de 

 la Vigne. [Defoliation. A defensive Measure against Vine 

 Pests.] — Bull. Soc. Etude Vulg. Zool. Agnc, Bordeaux, xv, 

 nos. 11-12, November-December 1916, pp, 118-122. 



The object of all processes in cultivation which are directed against 

 animal and fungus pests of the vine is to give air to the inflorescences. 

 This is done in four ways : by pruning, by tying up, by cutting back, 

 and by defoliation. Both of the last two methods result in a loss of 

 leaves to the plant. It is a well-known fact that certain hydro- 

 carbons, chiefly starch and glucose, can only be produced by the 

 presence of leaves, but a more important consideration is whether the 

 leaves supply reserves to the plant from the commencement of their 

 growth. Experience has shown that the process of cutting back a 

 vine, although it destroys many leaves, does not cause any diminution 

 in the quality or c^uantity of the crop, provided that the leaves thus cut 

 are undeveloped and the branches unripe and that sufficient leaves be 

 left to accomplish their physiological functions. The flowers or fruit 

 of the vine are naturally hidden under the foliage, but an insecticide 

 can obviously have no power over insects which it does not touch, and 

 the removal of a few leaves, at the moment when the young branches 

 are nailed or tied into position, will uncover the grapes and expose them 

 to the sprays used against Clysia ambiguella and Polychrosis botrana. 

 These moths occur chiefly on sheltered grapes, and those that are 

 exposed to the sun during the period of oviposition are always less 

 severely attacked. Experience has sho\\Ti that defence against these 

 pests is impossible without preliminary defoliation, but that it must 

 be done at the moment when the inflorescences are formed and before 

 the leaves removed are fully-grown. A second defoUation is recom- 

 mended if the fruit again becomes hidden by the development of the 

 leaves ; this gradual exposure prevents the grapes from being dried 

 up by the sun. As a rule, grapes should only be exposed during the 

 heat of summer, on the side furthest from the sun's rays. 



Sur la Resistance des Chenilles a Taction du Froid. [On the Resistance 



of Caterpillars to the Action of Cold.] — Bull. Soc. Etude Vulg. 



Zool. Agric., Bordeaux, xv, nos. 11-12, November-December 1916, 



pp. 126-127. 



Experiments have frequently demonstrated the remarkable 



resistance to cold of various Lepidopterous larvae, which can endure 



a temperature many degrees below freezing point and recover without 



apparent injury. Recent investigations have shoTvn that this power 



of resistance to cold varies according to the season and experiments 



conducted in the spring have given contrary results, low temperatures 



invariably causing the death of the larvae. 



Vaysiere (A.). Degats occasion6s par le Sirex gigas, L., [Hym.] dans 

 rinstallation des Chambres de Plomb d'une Usine du Midi de la 

 France. [Damage occasioned by Sirex gigas, L., [Hym.] in the 

 Lead-chamber Plant in a Factory in the South of France.] — Bull. 

 Soc. Entom. France, Paris, no. 17, 8th November 1916, pp. 273- 

 274. [Received 3rd January 1917.] 



A recent case of the larvae of Sirex gigas, L., boring their way through 

 the sheets of lead used in a factorv belongine: to the Chemical Produce 



