. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 21 CROPS AX]> PESTS OX WHKH THE fiAS HAS 15KEX SUCCESSFTTLTA' USED. Fer7i.'i.—For Jhiral/id. moorcana infested with a scale insect {Chioiiaspis up.), gram of 98 per cent potassium cyanide should he used for each cuhic foot of space to he fumigated, not deducting the space occupied hy the plants. Length of expo- sure, twenty minutes. One hundred and fifty to two hundred jylants with fronds in all stages of develop- ment have been thus treated two or three times each year for the past four years with no in
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 21 CROPS AX]> PESTS OX WHKH THE fiAS HAS 15KEX SUCCESSFTTLTA' USED. Fer7i.'i.—For Jhiral/id. moorcana infested with a scale insect {Chioiiaspis up.), gram of 98 per cent potassium cyanide should he used for each cuhic foot of space to he fumigated, not deducting the space occupied hy the plants. Length of expo- sure, twenty minutes. One hundred and fifty to two hundred jylants with fronds in all stages of develop- ment have been thus treated two or three times each year for the past four years with no injury to the plants and almost complete destruction of the insect. They were treated fifty at a time in a fumigating box (fig. 4.), described later. Adiantiim cuneatuvi and A. Bdll'd have been tried on a small scale and were not injured l)y the treatment. Colcm. —'' Bedder," " Yerschaffeltii," " Shylock,'' and others. 2-4,000 plants in pots, badly infested with the "white-tailed" mealy bug {Orthczia insigma). The house contained 15,587 cubic feet of si)ace. Treated at the rate of one-tenth of a gram of 98 per cent cyanide of potasli per cubic foot of space for twenty minutes, one hour after dark. Orthezia all killed and plants not injured in the least. All. Fig. -J.—Fumigating box showing trays and coleus cuttings (from Woods and Jjoisctt). other means of destroying the Orthezia had been tried without effect. Large num- bers of the common mealy bug were also killed by this treatment; but it was not nearly so effective as for the "white-tailed" mealy bug. All coleus cuttings made by the United States Propagating Gardens for the past two years have been fumi- gated l)efore being prepared for the cutting bed (see fig. 4). Douhle English violets.—'']\Iarie Louise," " Lady Campbell,'' and others. For plant- lice and general fumigation fifteen-hundredths of a gram of 98 jier cent cyanide of jwtash for each cul)ic foot o
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