162 Principles of Plant Culture. 
312. Leaf-Miners often infest spinach and beets grown 
for greens, rendering the leaves unfit for use. For these 
insects we can offer no preventive measures of established 
value. The application of powerful odorants to the young 
foliage, as coal tar water or a solution of carbolic acid, may 
prove beneficial. 
313. The Codling-Moth,* which causes so-called 
“ wormy’’ apples and pears, is controlled by spraying the 
trees at the time of egg deposit, with water con- 
taining Paris green (285). The first spraying 
should be given as soon as the petals (143) fall, 
to be followed by a second six to ten days later. 
If much rain falls at this season, the sprayings 
may need frequent repetition. A drop of poison- 
ed water should be lodged in the calyx (142) of 
every fruit, and as this evaporates, the film of 
poison deposited on the skin intercepts the 7) 
newly-hatched insect as it eats 
its way inward, and kills it. @ 
314. The Plum Curculio 
(306) that so 
often stings 
young plums, 
causing them Fie. 74. Fie. 72. Fru. 73. 
Fig 72. Card of tarred paper, for placing about the stems of 
to drop be- young cabbage and cauliflower plants. Reduced one-half. 
fore matur-  Fig.73. Tool for cutting the cards. 
7 a Fig. 74. Manner of using the tool. The dotted lines show 
ity, 1S CON- the position of the edge of the tool on the paper. 
trolled by jarring the beetles, that deposit their eggs in the 
young fruit, upon sheet-covered frames (Fig. 74), on cool, 
still mornings while the beetles are stiff. The jarring should 
* Carpocapsa pomonella. 
