386 



Sanders ((".. i:.) & Kelsall (A.). A further Report of the New 

 Copper-Arsenic Dust. — Proc. Ent. Soc. Nova Scotia, 1919, Triiro, 

 no. 5, February 1920, pp. 77-94. 



This paper is an amplification of one ah'eady noticed \^R.A.E., 

 A, vii, 303] and is published owing to the interest shown in the 

 results obtained with copper-arsenic dust. Subsequent field results 

 are described [loc. cit., ix, 228]. 



Spierenburg (D.). Eenonbekende Ziekte in de lepen. [An unknown 



Disease of Elms.] — Tijdschr. Planienziekten, Wageningen, xxvii. 

 no. 5, May 1921, pp. 53-60. 1 plate. 



An as yet undetermined disease is affecting elms in Holland. 

 Branches from some of these have been found to harbour Scolytiis 

 [Eccoptogaster) scolyUis, F., but infestation by this beetle seems to be 

 secondary. Typhlocyba sp. was also commonly observed on the 

 branches of affected trees. 



It is advisable to cut off all dead branches and to smear the wounds 

 with carbolinenm. If the beetle infestation is not too severe, 

 carbolineum of 30 per cent, strength should be brushed on the trunk 

 and branches in May, when the beetles begin to fly. This prevents 

 oviposition, and contact with this substance is said to kill the beetles. 



Beukenwolluis {Crypiococcus fagi, Dougl.). [The Beech Scale.]— 

 Tijdschr. Planienziekten, Wageningen,' xxvii, no. 5, May 1921, 

 pp. 61-62. 



The beech scale, Cryptococcus fagi, Dougl., hibernates in cracks of 

 the bark. It attains maturity in April-July, all the individuals 

 found being females. The eggs are laid from the beginning of June 

 to the end of October. The incubation period varies with the tempera- 

 ture ; in September-October from 45 to 50 days are required. 

 Temperature also influences the mobility of the larvae. In the middle 

 of a sunny day a larva is sometimes able to climb over 6 ft., so that 

 it may reach the crown of a tree in a few days. The pest spreads 

 during the period from June to November, wind being the chief 

 distributing agent. 



The injury done by this scale, which is slowly spreading in Holland, 

 seems to be less important than was thought at one time ; infestation 

 has to be very severe before much damage is done. 



Scrubbing with a 7| per cent, solution of carbolineum will free the 

 trees from infestation ; this treatment may be repeated if necessary. 



LiNXANiENXi (W. M.). Deltocephalus striatus, L. — Meddel. Soc. 

 Flora et Fauna Fennica, 1918-1919 ; Helsingfors, 1920, p. 2. 

 (Abstract in Wiener Landw. Ztg., 1921, no. 32-33.) 



In 1918 a leaf-hopper, Deltocephalus striatus, L., appeared on wheat, 

 rye and oats in south-west Finland and caused losses amounting to 

 several million marks. No such outbreak has been previously recorded 

 in Finland. 



