157 



their control, as well as the trainhig of entomologists. A prominent 

 place has been occupied by investigations into the control of pests 

 by means of parasites [see this Review, Ser. A, iii, p. 613], although 

 the author does not share the general great expectations connected 

 with this method [see this Review, Ser. A, i, p. 363]. Experiments 

 were also carried out on the effects of various insecticides on the 

 caterpillars of Lymantria dispar, and it was found that the fifth and 

 sixth stages are not affected by sodium arsenate or by azurgin (a 

 solution of Paris green in sal-ammoniac), while a 3 per cent, solution 

 of barium chloride with molasses destroys in hot weather up to 64 

 per cent., Paris green (4 grms. with 8 grnis. of lime in lOOcc. of water), 

 86 per cent., and lead arsenate, 70 per cent, of the caterpillars. 



Attention was also paid to the study of Eucosma (Ttnefocera) 

 ocellana, Argyroploce (Olethreutes) variegana, Hb., Tortrix (Cacoecia) 

 podana, Scop., Recurvaria nanelki, Hb., Chlorodijstis rectangulata, L., 

 Acrohasis obtusella, Hb. and Olethreutes achatawi, F. The following 

 insects were also observed on fruit trees : Tortrix {Pandemis) corylana, 

 F., T. (P.) heparana, Schifi., Oxygrapha (AcaUa) variegana, Schifi., 

 Tortrix (Cacoecia) crataegana, Hb., T. (C.) lecJieana., Coleophora 

 unatipeneUa, Hb., C. gryphipenclla, Bch., Tortrix laevigana, Hypsilophus 

 (Cerosfoma) persiceUus, F., and Trachoma (C.) horidellum, F. 



In 1915 one generation of Psylla jvjrisuga, Forst., occurred while 

 there were two of P. melanoneura, Forst., and P. albipes, Flor. 

 All three species hibernate in the adult stage in groups on the 

 trunks of pear trees. P. melanoneura oviposits in the first half of 

 March on branches of pear trees, the first larvae appearing at the 

 end of that month ; P. pyrisuga oviposits at the end of March on 

 buds. The local species of Psylla infesting apples is clearly distinct 

 from the central European, P. mali, L. ; it hibernates in the adult 

 stage on apple trees and oviposits in spring on the leaves ; though 

 only one generation occurs, the numbers of this pest have recently 

 increased yearly. 



A new pest in the Crimea, Aleurodes bragini, Mokr., was observed 

 in 1914, when it attacked and injured leaves of young pear trees ; 

 owing to the presence of parasites and to the frosts in autumn, it 

 practically disappeared in 1915 ; the life- history of this pest will 

 be more fully described in a separate paper. 



Besides Aphis pomi, De Gr., another, apparently new. Aphid was 

 observed on apples ; it gives rise to red galls on the leaves and migrates 

 to medlars, thus resembling A. crataegi, Kalt. The Chalcid, Syntom- 

 aspis pubescens, the observations on which were completed in 1915, 

 deposits its egg by means of a long ovipositor near the seed of the 

 young ovary of the apple-fruit. The larva on hatching out penetrates 

 into the soft seed, in which it lives ; it becomes mature in July and 

 hibernates in that stage ; in the middle of the following April it 

 pupates, the adult appearing in about a month's time through a 

 hole gnawed in the wall of the seed. It can emerge only in cases 

 where the fruit has already rotted. 



Other insects studied at the Station were : Procris (Ino) ampelo- 

 phaga, L., Emphytus truncatus, Kl., Anthonomus pedicularius, L., and 

 the following pests of stored grain, flour, etc. : — Calandra granaria, 

 L., Bruchus pisorum, L., Tenebroides (Trogosita) mauritanica, L., 

 Tenebrio molitor, L., Silvanus surinamensis, L., Sitodrepa panicea, 



