6 
when eaten by the insect. It is less poisonous to man than an arsen- 
ical, but not so effective to leaf-feeding larve. It may also be applied 
dry mixed with about double its weight, or more, of powdered plaster 
or cheap flour. 
When not in use the receptacles containing poisons should be 
plainly labeled “ Poison!” and placed on a high shelf or in a locker 
out of the reach of children. Properly applied, there is no danger, 
in using an arsenical on ornamental plants, of poisoning human 
beings, or domestic animals other than rabbits or similar pets. 
Soaps and other washes.—Oily soaps, such as fish-oil or whale-oil 
soap, and other soaps, and tobacco water will kill these insects, but 
their use is open to the objection that if apphed just before or at 
blossoming they are apt to injure the petals of delicate flowers, and 
whale-oil and tobacco also leave an unpleasant odor. <A neutral 
soap, such as castile or that used by physicians and surgeons, leaves 
no odor. 
Dry powders.—F ine, sifted road dust, where this can be readily 
procured, is also of value thrown upon the plants, preferably by 
means of a. powder bellows, as it closes the breathing pores of the 
larvee and thus kills them. Fmely powdered lime, and buhach (Per- 
slan insect powder, or pyrethrum) are also effective. 
Hand picking.—TIVf rose slugs are picked off by hand upon their 
earliest appearance this will greatly reduce their numbers for the 
following year. In the adult or “ fly ” stage these insects may be 
easily captured by hand on cool mornings. Hand picking may be 
tedious, but it is effective. 
Fall cultivating —lf other means that have been specified have not 
been utilized for the suppression of the slugs, many individuals may 
be destroyed by frequent cultivation of the soil between the rose 
plants during the late-summer and autumn. This has the effect of 
breaking up their pupal cells and otherwise disturbing the insects so 
as to interfere with proper hibernation. 
THE BRISTLY ROSE SLUG. 
(Cladius pectinicornis Fourcr.) 
The bristly rose slug, called also the spiny rose slug, is the principal 
enemy of the rose in and near the District of Columbia, not excepting 
the rose-chafer. It is believed to have been brought in from Europe 
some time prior to 1833, since it was mentioned by Harris in his 
catalogue of Massachusetts insects of that date. In the early 
seventies it was reported from Connecticut and in after years it made 
its way westward and southward, doing more or less injury where- 
ever established. Since 1880 it has done much mischief in Wash- 
[Cir. 105] 
