June i, 1890 . ] 
JOURXAL OF HORTICULTURE AND COTTAGE GARDENER. 
467 
two have been enlarged a little to render them visible. In No. 2 we 
find the blossom buds advancing towards expansion, and a casual glance 
at the tree would perhaps leave the impression that it was free from the 
pest; but examine the swelling petals closely, and it will be seen they 
have been pierced. This is made clear in the illustration, but the un¬ 
trained eye would not detect the “pin holes” without a magnifying 
'glass. In No. 3 three buds are attacked, two untouched, and the dif¬ 
ference is apparent. 
Turning to fig. 70, we see the results of the enemy in his citadel. 
^ •hows two buds with pistils and stamens partially eaten by the 
miniature caterpillars. No. 5 shows the “ pin-holes ” more clearly, 
and all the organs of fructification eaten. Nos. (! and 7 show the 
organs of Pear blo.ssom destroyed, and a small fruit attacked, with 
section indicating collapse. From the blossom we pass to the leaves 
for showing at once the efficacy and danger of Paris green. In 
No. 8 it has killed all the caterpillars on the leaf, but not the leaf 
itself, but in No. 9 it has killed all the leaves and flower buds, which 
hang flaccid and black. Here we have at a glance examples of the use 
and abuse of the poisonous preparation. The powder does not dissolve 
in water like sugar, but the fine particles are suspended in it by 
agitation. This must be constant or they will sink, and the water 
towards the bottom of the vessel be so heavily charged with poison as 
to destroy the leaves of trees to which it is applied, as the dead truss 
shows. 
It is better not to disguise the fact that Paris green is dangerous. 
■An entomologist writes in a letter before me, that owing to the insolu¬ 
bility of the substance “ grains of it are sure to lodge in the angles of 
twigs and branches, within buds, &c., and the probability is that after¬ 
wards, as the drying process is completed, these may be wafted through 
the air to the injury of peisons approaching the trees operated upon. 
Again, there is to be considered the effect of this potent article upon the 
trees ; first, in its being applied to branches and foliage ; secondly, by 
its descending to the roots, for in the spraying process some of the liquid 
must fall on the soil below. Chemists and fruit growers whom I have 
consulted are unanimous against its use, and there is really no difficulty 
in finding washes, which though less poisonous are quite efficient in 
caterpillar killing.” 
Herefordshire and Gloucestershire fruit growers will be very 
delighted to know what the washes alluded to are. Hellebore, petroleum, 
alum, quassia, and, so far as I know, every thing else that has been recom¬ 
mended have been tried, and while several preparations destroyed the 
Gooseberry caterpillar they have had no such effect on the larvse of the 
vrinter moth. The tenacity of life of these caterpillars seems remark¬ 
able. Immersion in strong solution of hellebore (8 ozs. to the gallon) 
did not kill them. They crawled about in petroleum and water stronger 
than could be applied to trees. Mr. Wise of Toddington says they 
“enjoy alum.” Mr. L. Castle has had them alive in Paris gieen water 
for twenty minutes. Nothing appears to kill them by contact except, 
perhaps, quassia and softsoap, and this has not been found efficacious 
at Glewston. The last recorded formula from there is 10 lbs. quassia 
chips and 7 lbs. of carbolic soap boiled together and mixed with 5 oz3. 
of Paris green with 100 gallons of water. That has answered so well 
both against the caterpillar and insects that, as we were told on page 
427, it will probably be the concoction in the future. 
Miss Ormerod’s recently^issued report, “Observations of Insects and 
Common Farm Pests during the Year 1889,” is a work of great value, 
fin which various caterpillar remedies are discussed, including Paris 
FIG. 71.—WINGED MALE AND WINGLESS FEMALE WINTER MOTHS. 
•green, and the paste form is recommended as the safest to use. It is 
there stated, on the authority of Dr. Lintner, that “ arsenic cannot be 
absorbed and assimilated by the plant in the economy of growth.” All 
farmers and gardeners should possess this Report,* which can be had 
for Is. fid. Paris green has been used in the United States 
* Loudon: Simpkiu, Marshall, HamiltOD, Kent & Co.| Limited. 
and Cansdi for years, and some of the large fruit growers there say 
that without it their occupation would soon be gone. At the same time 
anything equally efficacious for the purpose in question, and less 
poisonous, would be accepted as a boon by cultivators of fruit. 
The authors of the caterpillars, the winged male and wingless 
female winter moths, are represented in fig. 71. Their movements are 
A, shoot natural size, with eggs on bud ; b, stem natural size, with eggs In the end; 
C, the stem increased 5 diam.; d, egg magnided 30 dlam. 
nocturnal, and for the purpose of completeness the illustration of their 
nesting places (fig. 72) is reproduced. 
In connection with the depredations of the caterpillars, though not 
perhaps inseparably, Mr. W. G. Smith directs attention to an oidium 
that attacks Apple blossoms. He says, “ At this time of the year, and at 
the very time when the larv® of the winter moth are at their busiest, it 
is common to see the tenderest terminal leaf shoots and the blossoms of 
Apples attacked by a fine y> hite mildew. It is only when the attack is 
very bad that the mischief is noticed by gardeners ; slight attacks are 
generally unnoticed. As the mildew grows with virulence upon the 
stamens and styles, it follows that the resulting fruit is more or less 
injured, and in some cases totally destroyed. The fungus is an oidium, 
related to the oidium of the Vine, Hop, Strawberry, &c., and it often 
works hand in hand with the larvse of the winter moth. Up to the 
present time botanists have not given this oidium a name ; this is an 
extraordinary fact, as most small fungi are afflicted with a considerable 
number of names. The oidium of the Apple is probably an early con¬ 
dition of a fungus named Erysiphe communis, a common parasite of 
Buttercups, &c., or of Podosphffira clandestina, a common parasite of the 
Hawthorn. 
“ The illustration (page 468) will give an idea both of the work 
of the winter moth and the oidium in their attacks upon Apple blossoms. 
The left hand figure at A shows stamens w'ith their filaments and anthers 
badly eaten away by larva; at B and D ; whilst at c C is shown the 
flocculence caused by the oidium, enlarged ten diameters. The central 
figure shows the styles of the Apple blossoms badly eaten off by larvse at 
E and F, and destroyed by the flocculent growth of the oidium at G.also 
enlarged ten diameters. 
“ It requires a magnification of 200 diameters to see the nature of 
the mildew. This is shown in the right hand illustration at H, enlarged 
500 diameters. The oidium grows amongst the pollen grains as well as 
upon the stigmas, and to show the minute size of the fungus a single 
pollen grain of the Apple is illustrated to the same scale, resting on the 
oidium at J. 
“ When the larva; of the winter moth and the oidium make a 
combined attack on Apple blossoms there is of course no chance what¬ 
ever of fruit. The two pests, however, do not always work in company, 
but the oidium is often overlooked from its minute size, or its resem¬ 
blance to a minute healthy bloom.” 
After the illustrations above given it is hoped that those growers of 
fruit who have enjoyed happy immunity from the caterpillar scourge 
