380 Annual Report for 1913 of the Zoologist. 
genus Monarthropalpus. An attack on lime trees by a species 
of Thrips was reported from Windermere. 
Among the insects injurious to timber, complaints were 
received of the common Anobium and Xestobium beetles, but 
in some of the worst cases the beetles belonged to the genus 
Lyctus. 
By far the most important case of injury to forest trees 
brought to my notice during the year was due to the unusual 
prevalence of the spruce aphis. 
The Spruce Aphis {Aphis abietana). 
Complaints of plant-lice on forest trees are exceedingly 
common, but the pests generally belong to the genus Ghermes. 
The spruce aphis, Aphis abietana , has long been established in 
England, but is ordinarily negligible as a pest, having no 
appreciable effect on the common spruce, and I can find no 
record of its occurrence in sufficient numbers to be seriously 
injurious. This year, in April, reports were received from the 
Royal Gardens at Keiv that many spruce trees were in a very 
bad condition and some apparently dying, and their failure 
seemed to be attributable to no other cause than an unpre- 
cedented aphis attack. Further reports of similar attacks on 
Picea sitchensis in different parts of the country, and especially 
in Ireland, came to hand. As this species has been very 
extensively planted in Great Britain and Ireland during recent 
years the matter appeared to be very important. Two explana- 
tions were possible. A new pest might have been introduced 
with the Sitka spruce and become greatly more injurious in its 
new surroundings, or the already known spruce aphis, of which 
the common spruce is very tolerant, might be finding other 
species of spruce much more vulnerable. 
A visit was paid to the Botanical Gardens at Kew where 
the attack was severe, and where the presence of all the species 
and varieties of spruce would make it possible to determine 
the exact condition of affairs, and Mr. Dummer kindly showed 
me the trees. A large number of spruces were entirely brown 
and apparently dead, and many others presented a very pitiable 
appearance. At the first sight it seemed hardly possible that 
the aphis was accountable for such serious results, but close 
examination left no doubt that this was the case. The sickly 
trees were smothered in aphis, and every needle which had 
turned brown was marked with numerous perforations by the 
beaks of the insects. The species was Aphis abietana , — no 
new pest, but the species already known, though not regarded 
seriously as a pest in this country. 
An inquiry into the varieties of spruce affected gave the 
following results : — 
