423 



Henry (A.). Chermes attacking Douglas Fir. — Gardeners' Chronicle, 

 London, Ixvii, no. 1748, 26th June 1920, p 318, 1 fig. 



In view of the increased tendency to use Douglas fir and Sitka spruce 

 in afl'orestation schemes in England, attention is dra^vn to the presence 

 of Cherynes cooleyi in this country. This Aphid causes great damage to 

 these trees, and in the United States is known to attack Colorado and 

 Oregon Douglas fir. It is more common in the Rocky Mountains, 

 where it also occurs on Picea engelmanni and P. pungens. In the 

 Pacific coast region it has been found on Sitka spruce. In England 

 it has not yet been recorded from Colorado Douglas fir, even when it 

 is grown alongside infested Oregon Douglas fir. 



In Montana this pest has been successfully checked in nurseries 

 by spraying with kerosene emulsion. The importance of planting 

 absolutely clean seed is emphasised. 



Speyer (E. R.). Chermes attacking Trees of the Douglas Fir. — 

 Gardeners' Chronicle, London, Ixviii, no. 1751, 17th July 1920, 

 p. 36, 2 figs. 



Attention is drawn to the damage caused by Chermes cooleyi. Gill., 

 in Bagley Wood near Oxford, especially during 1919, in which year it 

 also affected a number of plants in the nursery. The " sistens " stage 

 develops in the spring from hibernating larvae. These adults are 

 situated on the old needles, on which they feed by sucking the juice. 

 Numerous eggs are laid by them and the larv^ae from these migrate 

 to the new shoots and cause them to have an unhealthy appearance. 

 By the end of May they have developed wings and disappeared, 

 probably to Sitka spruce. 



A few of the larvae remain wingless and are known as " progre- 

 dientes '' ; these lay eggs which give rise to " progredientes " or 

 " sistentes." The latter hibernate in the larval form until the 

 following spring. 



The winged form or sexupara on Sitka spruce produces a sexual 

 generation, all other generations being asexual. From this stage 

 onwards details of the life-cycle are not accurately known, and the 

 hfe-cvcle of the closely-allied Chermes strobilobius, Kalt., is therefore 

 briefly described. [R.A.E., A, viii, 138.] 



Fumigation with hydrocyanic acid before planting out m the forest 

 is advocated for the destruction of this pest. Damage by Chermes 

 is apparently most serious where the trees are planted on unsuitable 

 soU. 



VoGEL (J. F.). Over het Bestrijden van den Nonvlinder {Liparis 

 monacha.) [Measures against the Nun Moth, Liparis monacha.] 

 — Tijdschr. Plantenziekten, Wageningen, xxvi, no. 5, May 1920, 

 pp. 146-148. 



Early in August 1919 some adults and masses of pupae of the 

 mm moth, Liparis monacha, were observed near Loo in a forest 

 of about 150 acres of Pinus sylvestris aged 40-80 years. Collection 

 was carried out from 11th to 20th August, 100 children in squads of 

 10-15 being employed at a total cost of about £65. From a batch of 



