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hopelessly eigens before it is applied. ‘This year a batch of Acan- 
thaceous plants, such as Justicias, Aphelandras, &c., had been suffering 
from this sols disease for some weeks before it was noticed. The 
gardener in casis of the plants EE a fungus was the cause of the 
curling and discoloration of the foliage. By frequently dipping the 
affected plants in a weak solution of ei the plants were, in most 
cases, saved, and have since quite recove 
Ever cultivator Yaoi how easily irregulirity of temperature or 
ic moisture will bring on an attack of red-spider or thrips 
prem shais- grown under glass, and this mite, which is i 
either of the two pests named, and at least as area naar and 
injurious in its effects on the he health of the plant, can get a start e 
same cause, viz., bad ventilation or some other fault in the atitoépheié 
in the house containing the plants. 
Certain forms of black blotching and Sa which often dis- 
figure Masdevallias of the Chimera section and some others besides, 
are the work of an almost invisible nescit jcibibly a relation of the 
mischievous little red-spider. It must be sought for very carefully, 
- when discovered it requires some care and perseverance to get rid 
of i 
Specimens of the diseased plants were submitted to a well-known 
authority Wiio obligingly furnished the following report :— 
Mr. A. D. MICHAEL, F.L.S., to ROYAL GARDENS, KEW. 
Cadogan Mansions, Sloane Square, 
DEAR SIR, ovember 5, 1895. 
RE is not any doubt what the mite on your leaves is, nor any 
doubt that it is the cause of the damage. It is a Tarsonymus, the 
species is probably unrecorded; I think it most resembles Kirchnert, 
but is tinct ie between that and buxi. Icould make certain if it be 
either of these species if you wish it, but probably the minute differences 
would not interest you. The creatures ka this aee escaped observa- 
tion altogether until a few yea: cu nce of their minute 
size and mode of life; they ae ‘till y vere s nporleally known. They are 
all most destructive, attacking healthy plants and soon reducing them 
bad condition. Tarsonymus buxi practically destroyed all 
the foliage of the box trees in some of the Italian Botanical Gardens a 
ears aneo and in the Kew Bulletin for April 1 eeo; p- 85, you 
rt of my own upon sugar-cane — which was 
seriously ae from the same cause (species different). 
I I cannot give any very confident horam in the eradication 
of the pest. These Acari are leaf-mining things which burrow in 
rama -— two surfaces of the leaf and thus get protected. They are 
decis at dort irtérvida, with such solutions of soap and a 
or benzol, or carbolic acid as the respective plants will bear. Plant 
ealthy plants with solution of carbolic add, even if very 
Yours truly, 
(Signed) ALBERT D. MICHAEL. 
