19 



In the case of Siphonaphis padi, L. {Aphis avenae, F.) (apple-bud 

 or oat aphis) the author does not follow Baker [R.A.E., A, vi, 47] in 

 treating the insect infesting apple in North America as a distinct 

 species, A. prunifoliae, Fitch. Its life- history and habits in relation 

 to apple are discussed [R.A.E., A, iv, 484] and the various forms and 

 stages of each form are described. Tins species is not seriously 

 injurious to apple. 



The effects of attacks of Aphids on the apple tree and its fruit are 

 discussed [R.A.E., A, vii, 494]. The latter part of June is always 

 the most serious period for Aphid infestation, especially if temperature 

 and moisture conditions are favourable. During that time the stem- 

 mothers probably cease reproducing and most of them die. The 

 second and third generations are reproducing at their maximum rate, 

 and the fourth generation reaches its maximum about the last days 

 of June. After that time, the number of Aphids gradually decreases, 

 in spite of the fact that the young of A. pomi are being produced with 

 great rapidity. Weather conditions are however more favourable 

 for parasitic and predaceous enemies and these are then able to gain 

 the upper hand. 



Jardine (N. K.). The Tea Tortrix {Homona coffearia, Nietner).— 

 Spolia Zeylanica, Colotnbo, xi, no. 41, October 1919, pp. 191-192. 



The tea tortrix, Homona coffearia, is redescribed in this note. 



DE MoNCHAUx (D.). Dc I'lnnuencB des Migrations et des Introduc- 

 tions aceidentelles.— 5i<ZZ. Soc. Nat. Acclimat. France, Paris, Ixvii, 

 no. 10, October 1919, pp. 308-316. 

 Attention is drawn to the influence that insect migrations exercise 

 on the distribution of plant pests and diseases. The importance of 

 this question is increased by the fact that migration is frequently 

 the result of changes in environment. Many examples to illustrate 

 this, as well as the adaptation of insects to new surroundings, are 

 quoted. 



Gahan (A. B.). Report on a small Collection of Indian Parasitio 



Hymenoptera.— Proc. U.S. Nat. Mus., Washington, D. C, 1919, 



Ivi, no. 2299, pp. 513-524. [Received 20th November 1919.] 



The new species described include : the Eurytomids, Bruchophagus 



mellipes, reared from galls in daincha [Sesbania] pods and pods of 



Vigna sinensis (red gram), Eurytoma parasae, parasitic on Parasa 



lepidaand Thosea sp., and E. denticoxa, from maize seeds ; a Chalcid, 



Stomoceras ayyari, from cocoons of Parasa lepida ; an Encjrrtid, 



Aphycus fiiscidorsum, parasitic on scale-insects on lab-lab, probably 



Dolichos sp. ; and a Pteromalid, Eupteromalus parnarae, parasitic on 



the Hesperid, Parnara mathias, on rice. 



Pkmberton (C. E.). Leafhopper Investigations on Havvm.^Hawaiian 

 Planters' Record, Honolulu, xxi, no. 4, October, 1919, pp. 194-221, 

 10 figs. 

 This is a preliminary report of investigations during June and July 

 on the sugar-cane leaf-hopper in Hawaii [Perhinsiella saccharicida], 

 with particular reference to its parasites and the causes of its con- 

 tinued abundance in spite of remedial measures. 



(633) ^2 



