486 



and the larvae mine in the cambium, causing an exudation of gum. 

 Sickly trees are most usually attacked, and these should he taken 

 np and burnt. Healthy trees should be protected by a coating of 

 lime on the trunks and main branches. 



PouTiERS (R.). Le Teigne de la Pomme de Terre. — Rev. flortic. 

 de VAIgerie, Algiers, xxiii, nos. 6-7, June-July 1919, pp. 285-287. 



Phthoriynaea operniMla (potato tuber moth) has recently been 

 found to occur in a very limited area in the Department of Yar 

 (France), where it principally attacks stored potatoes. It has, however, 

 also been found on the plants, as well as on other Solanaceae, such as 

 tomatoes, nightshade, egg-plant, pimento, tobacco, etc. A general 

 account is given of the habits of the moth and the known methods 

 of control. As fumigation is not always feasible, it is hoped to 

 establish colonies of a small Braconid, which is a parasite of 

 P. operculeUa in the United States, as a natural means of control. 



Paillot (A.). La Karyokynetose, nouvelle Reaction d'Immunite 

 naturelle observee chez les Chenilles de Macrolepidopteres. — 



C. E. hebdom., Acad. Set., Paris, clxix. no. 8, 25th August 1919, 

 pp. 396-398. 



Further experiments with Bacillus melnlonthae nonliquefaciens on 

 caterpillars of Nygmia phaeorrhoea {Euproctis chrtjsorrlioea) and 

 Lymantria dispar are described [see this Revietv, Ser. A, vi, p. 131 

 & vii, p. 217]. These moths appear to be immune to this infection. 

 The resulting cellular reaction is described. Bacillus liparis and 

 B. Jioplosternus give rise to similar conditions. 



MoREiRA (C). Les Pucerons et leur Oeuf d'Hiver. (Hem. Aphididae). 



[Aphids and their Winter Eggs.] — Bull. Soc. Eniom. France, 

 Paris,. 1919, no. 13, 9th July 1919, pp. 236-238. 



It has been known for many years that Aphids lay winter-eggs 

 in order to ensure the maintenance of the species in climates where 

 the winters are severe. When individuals of Aphis rosae were kept 

 for four years in a warm room during winter and out of doors in 

 summer, parthenogenetic, viviparous reproduction was continuous; 

 while others, kept out of doors and without shelter produced, at 

 the approach of winter, sexual individuals that mated and deposited 

 winter-eggs. It was therefore concluded that in regions where there 

 is no severe weather Aphids would not produce sexual individuals 

 or winter-eggs. The author's observations on A. nerii, Boy. 

 {Julescens, Mon.), carried out during four years in Eio de Janeiro, 

 where it lives on Asclepias currassavica and on Nerium oleander, have 

 demonstrated that the reproduction of this species is always partheno- 

 genetic and less lengthy observations on other Aphids have confirmed 

 this. WTien the munber of Aphids on A. currassavica is sufiicient 

 to cover all the jjranches and leaves, so that the plant dies and the 

 food fails, while at the same time the attacks of insect enemies begin, 

 the winged forms begin to appear and fly or are blown to another 



