26 



was also tried in nature against the gooseberry sawfly {Pteronus rihesii) 

 with great success ; the disadvantage of this insecticide is its high 

 price. 



The results of these experiments are summarised by the author as 

 follows : Vegetable decoctions are quite practicable as insecticides 

 and never cause any scorching. Their disadvantages consist in their 

 rapid fermentation, to prevent which they must be prepared directly 

 before use with the addition of some soda. Even weak vegetable 

 insecticides are of some value, as they lower the vitality of caterpillars 

 feeding on plants sprayed with them. They are considered to be 

 deserving of serious attention and to offer a wide field for further 

 investigation. 



DoBEODEiEv (A. I.). BntAHOHoriw BMUiHeBbiii nMnnnbiMMKij m 6opb6a 

 CT) HMMTj. [Priophorus jiadi, L., and its Control.] — « Samnia 

 paCTeHJM OTIj BpeflMTeneM.» [The Protection of Plants fmnt. 

 Pests], Supplement to «JlH)6MTenb flpupoflbl.)) [Friend of 

 Nature], Petrograd, 1916, no. 1-2 (28-29), pp. 38-44, 5 figs. 



The sawfly, Priophorus padi, L. [Cladius olbipes, Eversm.) injures 

 cherry, plum and service trees ; it is found also on blackthorn, birch, 

 medlar, bird cherry, roses, dewberry and raspberry. In the govern- 

 ment of Kiev it has done serious damage in the orchards. The females 

 oviposit in spring on the central vein of the leaf on its lower side. The 

 larval stage lasts three weeks. According to Theobald, pupation takes 

 place in the soil, but the author doubts the accuracy of this statement, 

 pupation usually taking place, in his experience, beneath leaves or other 

 debris on the ground. The insect hibernates as a mature larva and 

 two or three generations occur during the summer. The larvae are 

 attacked by parasites, including the Tachinid, Ptychomyia selecta, and 

 the Chalcid, Dihrachys bovcJieamts, Thorns., while, according to 

 Theobald, they are also infested by the Ichneumons, Ichneiites reunitor, 

 Nees, and Tryphon luciduhis, Grav. It is probable that infestation by 

 P. selecta does not take place through actual oviposition on the skin of 

 the host, but by the host swallowing the eggs of the parasite deposited 

 on its food-plants. Similar phenomena are known in the case of other 

 Tachinids, such as Phryxe vulgaris {Blepharidea scvfellaris) and Crosso- 

 cosmia sericariae. Dihrachys boucheanus is probably a h}'per-parasite. 

 The remedies against this pest include :~ Spraying with Paris green 

 and the removal and burning of the debris on the ground round the 

 trunks. 



SoKOLov (N.). OsMMafl coBKa, no Ha6jiH)fleHiflM-b ntiOM-b 1915 r. 

 B"b TaMSOBCKOil rySepHJM. [Euxoa {Agrotis) segetum, L., and 

 Feltia exdamalionis, Schiff., in the govt, of Tambov in the Summer 

 of 1915.]— « 3au4MTa pacieHiM OTT* BpefillTeneM.» [The Protection 

 of Plants from Pests], Supplement to « Jlio6MTenb npMpOflbl.» 

 [Friend of Nature], Petrograd, 191G, no. 3 (20), pp. 1-L'j. 



This is a report on observations made by the author jointly 

 with N. F. Meier and I. I. Voskoboinikov, during the summer of 1915 

 in the government of Tambov. Large outbreaks of Noctuid cater- 

 pillars occurred in the Borisogliebsk district of the government in the 

 autumn of 1911 and spring of 1912 and again in 1913-14, when large 



