169 



plants was observed from this substance, either in the laboratory or in 

 the open, when it was used as a 6 percent, solution for the control 

 of caterpillars of Cheitnatobia brumata in one orchard in April. Owing 

 to the small size of the caterpillars at that period, they perished in a 

 few hours after the spraying, whereas experiments in the laboratory 

 on adult caterpillars caused death only after 24 hours. Purple was 

 also used with success for the control of Phlyctaenodes sticticalis. 

 Experiments have shown that some plants can stand even a stronger 

 solution without showing signs of scorching ; pear-leaves showed no 

 scorching even from a solution containing 52 oz. of purple in 27 gallons 

 of water ; plum trees were slightly affected by a solution of this 

 strength, while almonds suffered even from a solution of 30 oz. in 

 27 gallons of water. 



Pliginsky (V. G.). OnbiT"b yMeia peaynbiaTOB-b OKypMBaHifl moah- 



HMl^bl. [An experiment on estimating the results of fumigation 

 against Psylla mali, Schm.] — «CaAOBOfl"b.» [The Horticul- 

 turist], Rostov-on-Don, xv, no. 2, February 1916, pp. 101-103. 



Doubts have been expressed by some authors whether fumigation 

 with tobacco smoke, really destroys all the Psylla present, or whether 

 some individuals are only temporarily stupefied. The author describes 

 experiments in estimating the actual effect of this method, in which 

 sheets were placed underneath the trees and everything found on them 

 after fumigation was collected into boxes and examined. It was 

 found that Psylla mali is totally destroyed by this means and of over 

 8,000 examples only about a dozen showed any signs of life. On the 

 following day no Psylla were to be seen in this orchard, except a few 

 individuals on trees adjoining neighbouring orchards, where no 

 fumigation had been carried out. The fumigation does not however 

 affect many of the parasites. This method of control is considered 

 the cheapest and most effective, if properly applied, but it ought to be 

 carried out simultaneously in all adjoining orchards. 



Emelianov (I. A.). TexHMKa nociaHOBKn onbiTOBii no c.-x. 3htoiiO' 



noriM. I. TepMOCTaibl M rMrpoCTaibl. [The Technique of Experi- 

 ments in Economic Entomology. I. Thermostats and Hygrostats.Jj 

 — Published by the Entomological Department of the Charkov 

 Agricultural Experimental Station, no. 1, Charkov, 1915, 53 pp.,, 

 22 figs. [Received 22nd March 1916.] 



In this paper the author describes and figures in detail various forms 

 of apparatus for controlling temperature and moisture, used in research 

 work in Economic Entomology. 



The incubators described include those (1) for a temperature lower 

 than 0°C., which are necessary when studying the conditions of 

 hibernation of insects, the influence on them of sudden changes in 

 temperature, etc. Of this type of apparatus, those dealt with include 

 the one used at the Tennessee Experimental Station (described by 

 E. C. Cotton in a paper read at the 22nd Annual Congress of American 

 Entomologists) which gives very low and constant temperatures, but 

 is expensive, and the apparatus of S. Hunter ; neither of these is 

 ventilated and there is no means of regulating the moisture. 



(C259) B 



