A-pril -.’0. 1<J93. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENEIL 
821 
PhytoptuG tillse, and Reaumur is believed to have seen the makers of 
the galls a hundred years before anybody else. 
Now there are only five species of bud gall mites. Phytoptus betuli, 
living in Birch buds ; P. coryli, infesting Hazel buds ; P. persicm, 
attacking Peach buds ; P. ribis, living in Black Currant buds ; and 
P. tazi, infesting Yew buds. None of these has been proved to live in 
leaf galls, or in erineum hairs on the leaves. There certainly is a 
resemblance to each other in all mites, otherwise they could not be 
formed into one genus, but there is also a difference, hence their division 
into species, and the view of mites transferring their attacks—living in 
summer in leaf galls or erineum and in winter in bud galls—is mere 
conjecture. 
The Hazel bud gall mite would be most likely, assuming the mites to 
have different hosts at different seasons, to exist on the Thorn or Maple 
in summer ; but the Thorn Phytopti is a transparent whitish creature, 
and appears in May, forms erineum rust on the turned-up edges of the 
Apple tree, Phytoptus pyri and P. mali. These are transparent white, 
accord well with Scheuten’s sketch (copy) at the Bethnal Green branch 
of the South Kensington Museum, Aptera, case xvii., No. 4, and they 
never attack the buds of the Pear or Apple, and only leave the trees 
when forced to emigrate through scarcity of food. They, however, 
do something quite as bad, or worse—produce a knotted, warted, 
cankerous condition of the twigs, which becomes scaly in the limbs, 
weakens, and sometimes kills the trees, as I observed in three orchards 
lately. Mr. Harrison Weir and Mr. J. Hiam are in this respect quite 
right as regards this form of canker, and once a tree, Apple or Pear, is 
attacked by these mites it continues so year after year, adjoining but 
detached trees remaining free for some time, or until the infested trees 
become impoverished or dies, then emigration sets in in earnest, and 
the disease-resisting trees, so called, become a prey to the mites. The 
leaf gall mites, however, are in some cases great rovers, P. oxyacantha, 
Am, being, perhaps, the most remarkable ; but the bud gall mites carry 
Fig. 61.—HAZEL-BUD GALL MITE; INFESTED AND CLEAN GROWTHS. 
KEKEKENCES TO THE Illustbation :—A, Hazel twig, natural size; a, buds infested with Hazel-bud gall mite, Phytoptus corjli; j, unattacked terminal 
bud; h, basal bud; m, catkin-bud destroyed; n, wood bud by the side of catkin-bud; o, point of cutting off infested growth for burning. B, very small sectional 
part of bud gall, greatly magnided; 6, mite browsing on stumpy hair; c, mite passing from one stump to another; cl, mites holding by their caudal appendages and 
clasping the stump ends with the maxiU® (lips); e, mite at rest; /, eggs of mite. 0, specimen mite, greatly magnified. D, egg of mite, highly magnified ; p, nucleus or 
head. E, sac drawn out by mite before emerging, highly magnified. P, empty sac, greatly magnified. Cl, twig of Hazel infested with gall mites; 1-, terminal bud attacked, 
also the next below ; I, unattacked wood bud ; i, basal buds. H, clean growth of Hazel twig, natural size; p, terminal growth, with nut cluster in centre. Ail tlio figures 
are from life (April 7th, 1893) except E and F, which are from 1892 drawings, to the same enlargements as B, O, and D. 
leaves of a greenish yellow colour ; they also form light brown egg- 
shaped bells and club-like galls. When autumn arrives these Phytopti 
have blackened and destroyed the points of the young shoots. They are 
not bud gall makers. Phytopti produce beautiful galls on Maple leaves. 
They do not enter the buds in autumn and make galls of them for their 
winter sustenance. 
On the other hand, there is not any erineum on Hazel leaves in 
summer, and the nearest resembling mites are those of the Pear and 
off the palm for emigration and devastation, the Hazel bud mite being 
widely distributed. 
This mite does not leave the attacked buds before the Hazel is well 
in leaf, and the young buds forming in the axils of the leaves. 
The young growths, shoots, and leaves are hairy ; the mites, as shown 
by the late Professor Clapar5de, possess hair-claspers, which he, 
as well as the late Mr. C. Darwin argued, “ must have been independ¬ 
ently developed, as they could not have been inherited from a 
