HOPS. See HUMULUS, (Encycl.) The cultivation of hops, which is now so very general, is not in
all places equally successful. Very large hop-grounds will for 20 years successively appear with the most promising verdure, yet produce nothing. When the fructification in an early state contracts a mouldiness, it withers and is destroyed. It is then infested by the aphides, who produce on it what is commonly called an honey-dew; but the plant must first be in a sickly state before it is infested with these insects. Into this situation it is reduced by the caterpillar of the phalena humuli or other moth, which feeds on its roots; a circumstance of which the cultivators of this plant are generally ignorant, though some of them have discovered that a found hop will be infested by planting a sickly one near it, when they transplant the roots from a hop-ground that is thus attacked to one that is perfectly healthy. The hop grows naturally among stones and fragments of rocks, where it is never damaged by the honey-dew. The reason is, that the caterpillar abovementioned, cannot in such a soil penetrate to its roots; and therefore, those who cultivate this plant ought to cover the ground with stones.