September 7, 1893. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
223 
or growing point are galled all over. The mites also have galled the 
shoot at h ; that is how and where canker in Pear trees caused by mites 
begins. Examine the galls as we may, and search every particle of leaf, 
not a mite is to be found. But the givlls swell rapidly, assume a darker 
hue, and a section through a gall early in August reveals mites browsing 
in erineum and laying eggs. This is shown at c, in E, section through 
a developed gall ; and examining a similar gall later, say early in 
September, we find the erineum gone, and the mites full fed, as shown 
at d. The mites go in and out by the opening, and may be seen on the 
leaf surface, only disturb the upper side of the gall. They are invisible 
to the naked eye, and only just made visible by a good pocket lens. 
Under a powerful microscope the mite is seen to have a lily-white body, 
two pairs of legs near the head, which has a pale flesh tint, and ends in 
a conical projection, containing the fine sword-shaped jaws and other 
mouth apparatus. This, shown in the figure at F, is less than 1-200 inch 
in length, and about 1-800 inch in breadth. 
If examined microscopically later on in the summer only old mites 
are found in the galls. There are plenty of skins, and some long lumps, 
mite-like but shorter, without legs or bristles, and soon afterwards 
empty (and much shorter than the bodies of the mites) receptacles are 
formation of the galls lurking in Pear-tree leaves in early summer ? Why 
do they not deposit eggs in the first formed galls ? What apparatus are 
they provided with to pierce through the lower cuticle of a leaf ? and how 
can they deposit an egg in a hole four times less than its diameter 1 
Why is a four-legged mite egg or bud never seen in a gall but where there 
are already the mites ? On what do the four-legged mites subsist from the 
fall of until the appearance of the leaves in spring? The questions are 
the objections to the mites being always four-legged, and the only 
one met is that the mites live on the buds during the winter. If so, 
why are the mites never found in the buds? 
2, Assuming the mite to be always four-footed, do the mites ever 
mate ? Are not they strictly confined to parthenogenesis ? Will par¬ 
thenogenesis endure indefinitely ? f-r"A 
3, Granted the mites pass the winter in the six or eight-legged state 
in the fallen leaves, how does it happen that if a tree is cut down or pol¬ 
larded that the mites do not attack the leaves of the sprouts springing 
from the trunk ? 
4, If the mites are six or eight legged, why do they not deposit eggs 
in the holes first pierced ? This, of course, tells against them, and is the 
grand secret, that is, they do, but they are not seen, for they are 
found in the galls. Do not get alarmed if cut off legs as large almost as 
the fingers move up and down, for they are only the belongings of enemies 
to the mites, which they devour and clear out of the galls, except such 
as escape. If the section be rather a thick one, say one-sixteenth inch, 
it is possible that one of these creatures may be seen in perfect con¬ 
dition, and it is very unsightly. A four-legged mite can parade on a 
joint of one of its legs easily ; but keep a steady gaze, then sooner or later 
an active creature with six or perhaps eight legs will flit over the section 
—in and out, everywhere in no time, so that it is difficult to get a good 
examination of these interesting creatures. The best way is to immerse 
the section of a gall in alcohol for about a minute, but the mite is very 
difficult to find after the emersion. The best I have yet been able to 
sketch is seen at G. This is the male; the female is larger, has also 
eight legs, the two hinder divided into two hair-like extremities, 
each for steadying her when depositing eggs, and in spring a long 
ovipositor, very singular and not depictable. These mites are the 
last occupants of the galls, except the animal that clears out the 
four-legged mites, and may be a Cheyletus. The six and eight-legged 
mites are seen on the leaf at the mouth of the galls, then they are found 
on the trees before the leaves fall, and they are seen on the trees in 
spring lurking in the cracks and crevices of the bark, their favourite 
haunts being the cankerous places their parthenogenetic progenitors have 
caused, as/in H. Now we have to face a few difficult questions. 
1, The mite (Phytoptus pyri) and all the sub-family Phytoptidae 
are four-legged. Where are they from the fall of the leaf until the 
enwrapped in the substance of the gall, and are not visible because 
opaque. 
Concluding, H shows a twig of a Pear tree cankered by the 
Pear-leaf gall mite. It is distorted at /, and the spurs g have been 
killed by the parasites. Such trees can only be cured by killing the 
mites. There is nothing better for all mites than syringing the infested 
trees with a sulphur solution, for all Arachnoidea succumb to it. It 
may be made as follows : Slake 3 lbs. of quicklime in an iron copper, 
adding 2 lbs. of flowers of sulphur and 3 gallons of water, besides that 
used in slaking the lime. Mix and boil for a quarter of an hour, keeping 
stirred all the time. Allow the mixture to settle, and when cool pour 
off the clear liquid, place in stone bottles, and keep well corked in 
a dark place. Use a pint of the bisulphide of calcium, as the liquor 
is called, to 4 gallons of water, applying with a syringe or engine. It 
may be used in winter to kill ihe mites in the lurking places on the 
trees when the buds commence swelling, or as a preventive in spring 
when the shoots are about 2 inches long or the first leaves about half 
developed, using 1 pint to 12 gallons of water, repeating occasionally. 
At the strength first named it must only be employed over mature 
foliage, say in September. ..... t. 
The Apple tree gall mite (Phytoptus mali) is similar to P. pyri m 
its effects on Apple trees in producing canker, but differs in several 
essential points entomologically, especially in the gall formation, which 
is the only part about mites which has been well worked out.— 
G. Abbey. 
