41 



Flint (W. P.)- The Effect of Cyanide on the Locust Borer and 

 the Locust Tree. — Science, Lancaster, Perm.., xlii, no. 1090, 

 19tli November 1915, pp. 726-727. [Received 4th December 1915.] 



Experiments were made during the latter part of 1914 and the early- 

 part of 1915 in connection with the control of Cyllene robiniae (black 

 locust borer), to determine whether at least a part of the borers in 

 infested locust trees might be killed by introducing small amounts of 

 potassium cyanide into the trunk. The trees selected were from one 

 to seven inches in diameter and were badly infested with the larvae 

 of the borer. The cyanide was placed in holes varying from one- 

 quarter to one inch in diameter, bored at different heights from the 

 ground. The chemicals used were pure potassium cyanide in small 

 lumps and cyanide-chloride-carbonate mixture in granular form, 

 containing from 35 to 38 per cent, sodium cyanide. Examination of 

 the trees four months later showed that they had derived no benefit 

 from the treatment. Of the 42 trees examined in July, 19 were living 

 and of these 16 contained living larvae of C. robiniae. In several 

 cases, living borers were found close above the holes in which the 

 cyanide had been placed. The death of so many trees was not entirely 

 due to cyanide, although the latter had a very injurious effect, since 

 the bark was dead and the wood discoloured for some distance around 

 the holes. In many cases the portion of the trees round the holes had 

 been gnawed by rodents. 



Shevirev (I.). Note on Retinia sp. as a forest pest in Russia. 



With regard to the species of Rhyacionia {Retinia) infesting the 

 forests of Tambov [see this Review, Ser. A, iii, p. 728], Dr. Shevirev 

 writes that R. dwplana is chiefly concerned, but that the foresters 

 frequently mistake the very similar damage done by a fungus, Coeoma 

 'pinitorquum, for that caused by the moth. This fungus is much the 

 commoner in Russian forests and he has had many opportunities both 

 from personal observation on the spot and from material sent for 

 examination, to satisfy himself that such is the case. 



Keuchenius (P. E.). Het vraagstuk van de gramangmier {Plagiolepis 

 longipes) tevens een kritiek. [The question of the Gramang Ant 

 {Plagiolepis longipes) and a criticism.] — Reprint from Tijdschrift 

 Teysmannia., Batavia, 1915, no. 6 and 7, pp. 382-394. 



This paper is almost entirely concerned with the question as to 

 whether P. longipes should be considered a pest, and the opinions of 

 various authors are cited and criticised. The author has arrived at 

 the conclusion from personal knowledge and observation that P. longipes 

 is harmless to cacao and directly useful to coffee because it largely 

 • checks the development of red fungus, plays an important part in the 

 spread of the white scale fungus {Cephalosporium lecanii) and is 

 predaceous and kills many other insects. For these reasons, it is 

 believed that attempts to control it in cacao and coffee plantations 

 are not only useless, but waste of time and money. 



(C238) Wt. P12/91. 1.500. 2.10. B.& F.Ltd. G.11/3 A 



