_Mealy Bug._ The mealy bug inhabits a white, cottony looking mass, which is easily seen. Remove this covering and the real intruder is there. It is most fond of the soft-wooded plants, such as coleus and fuchsias, thrives in a hot, dry atmosphere, and will keep out of sight, if not watched for, in a mass of leaves or under some branch axis, until there are a large number.
If they are discovered before multiplying to any great extent, exterminate them with a fine brush or feather dipped in alcohol, coal-oil or kerosene, any of which, if applied directly to them, will kill them on the spot.
_Scale._ The scales infesting house plants are of two kinds. The more common is the brown scale, which has a hard, slightly convex, circular shell, one-quarter of an inch or so in diameter. The white scale is much smaller, and soon forms quite dense colonies. Both attack the thick-leaved, smooth-barked plants, such as palms, ferns, lemons, and abutilons. They do not appear to be doing any damage, but invisibly suck the juices of the plant. They should be destroyed at once. This is accomplished by the use of fir-tree-oil soap, whale-oil soap, or kerosene emulsion and a stiff brush.
_Thrips._ These do not often appear in the house, but may where plants are crowded in a shady place. They eat the substance of the leaves, leaving only the skeleton structure. They are small, about a quarter of an inch long, and brown or black. Aphine, kerosene emulsion or Paris green (one teaspoonful to twelve quarts of water) will keep them quiet.
_Root Aphis._ Sometimes the leaves of a healthy plant will begin to look sickly with no apparent cause. It may be found upon examination that the blue root aphis is at work, clinging in clusters to the rootlets. Remove and wash away the soil, and then wash the roots in whale-oil soap suds, and repot in fresh soil. If no fresh soil is available, tobacco tea or tobacco dust should be washed into the soil every other day for a week.
_Soil Worms._ The common earthworms sometimes find their way into a pot, and while they do not seem to bother the roots, I should judge from observation that they render the soil next to useless, especially in small pots. Another worm, or rather larva, sometimes to be found, is very small and hatches into a small white fly. If numerous, they do a good deal of damage. The treatment recommended for root aphis will get rid of them; or lime water (slake a piece of fresh lime the size of an apple in a pail of water, drawing off the water after settling), if used freely will kill them.