Annual Report for 1913 oj the Zoologist. 381 
The common spruce (P. excelsa , type variety) showed no 
sign of having suffered at all, and it was only after some search 
that specimens of the aphis were found upon it. Some of the 
ornamental varieties of P. excelsa were, however, badly injured, 
especially the varieties gigantea , aurea , hudsonica , repens , 
virgata , and monstrosa. It was very noticeable that one 
variety — P. excelsa var orientcilis — showed no signs of injury 
whatever. ' „ , 
But the worst cases were those of the more recently 
introduced American species of spruce, P. pungens and 
P. sitchensis ; many of these trees seemed as though the^ 
could hardly recover from the attack. The facts, then, are 
these : No new pest is in question, but our old spruce aphis 
is under exceptional conditions, capable of greatly damaging 
p. sitchensis and P. pungens , and also many ornamental 
varieties of the common spruce, though the type variety and 
also the variety orientalis escaped injury even when the aphis 
was unusually abundant. Of course the conditions were 
highly exceptional. For an aphis attack to occur in sue 
severity and so early in the year as to kill forest trees before 
the end of April is, I believe, unprecedented, and it may be 
long before it occurs again. No doubt the mild winter was 
partly responsible for it. There is one practical lesson to be 
learnt from the attack. We may disregard the presence of 
aphis on the common spruce, but on the Sitka spruce it is 
another matter. In view of the great harm it is capable of 
doing it will be advisable to watch plantations of young bitka 
spruce for its appearance, and, where possible, to wash the 
trees as soon as the pest does occur. , 
Mr Diimmer made an interesting suggestion as to the 
reason why certain species and varieties of spruce are more 
vulnerable than others. He points out that the affected trees 
are generally characterised by the possession of particularly 
sharp needles, which, he thinks, may deter tits and other birds 
from clearing off the winter forms of aphis which give rise to 
the spring attack. The blunter needles of the common spruce 
do not repel them, and these trees are probably, therefore, more 
effectually cleared of the hibernating aphides. 
Farm and Garden Pests. 
There is little of special interest to record in this section. 
Some of the spring pests appeared at a remarkably early date, 
and there was even a case of frit-fly in winter oats. Many 
enquiries have had reference to clover crops, which in different 
cases have suffered from eel-worm, clover seed-midge, and 
weevil grubs, as well as from the fungus Sclerotima. In the 
autumn there was an unusually severe attack of celery-fly. 
