saccharidica), a species belonging to the family Fulgoridae. In 1903 this insect became so abundant as to prove a serious menace to the cultivation of sugar cane. For several years it caused a loss of about $3,000,000 annually to the planters; but it has been brought under control, and to-day the plantations are again producing heavy crops of sugar. The honey-dew from the sugar-cane leaf-hopper is very dark amber in color and slightly ropy. In flavor it strongly resembles molasses. While most honey-dews granulate very rapidly, this type does not granulate at all. Samples several years old are as clear as when first extracted. A small amount of this honey-dew mixed with the light-colored algaroba honey imparts its color and flavor to the entire amount. Bees prefer floral nectar to this excretion; but when the floral nectar is not abundant they gather both, and the honey is a mixture.
The chemical composition of Hawaiian honey-dew honey differs so widely from floral honey that many buyers on the mainland have charged that it was adulterated; but after careful investigation Phillips was convinced that it was a natural sweet product collected by the bees, and shipped without the addition of other sugars. It is not placed on the market in competition with the honeys of the mainland derived from flowers, but is sold to bakers as honey-dew.
Analysis (see table) of the honey-dew honey of the sugar-cane leaf-hopper shows that the ash content is very high, ranging from three to six times the amount found in normal floral honeys. The percentage of dextrine is also very high, and its acidity is three times that of algaroba honey. The percentage of sucrose or cane sugar is a little higher than that of the average of floral honeys. A ray of polarized light is turned to the right by the honey-dew, while pure floral honey turns the ray to the left.
The Coccidae are commonly known as scale-bugs, scale-insects, bark-lice (Fig. 5), mealy-bugs, and coccids. The species are very numerous and infest the bark and foliage of a great variety of plants, and also nearly every kind of fruit. They excrete great quantities of honey-dew both in temperate and tropical regions. Only the adult females exude honey-dew. Not all of the species produce honey-dew, as many excrete wax or resinous substances. In early autumn a large quantity of honey-dew is frequently gathered from oak trees, the limbs of which are covered with a great number of small coccids, gall-like in form, about a quarter of an inch in length, from the ends of which there flows continuously a clear sweet liquid. So profusely is the honey-dew exuded that the trees appear as though they had been sprayed with hundreds of gallons of it. When it dries it solidifies and hangs in small stalactites. This honey-dew is produced, not by galls, as is often reported, but by the adult females of Kermes galliformis, which are remarkable for their gall-like form. “So striking is the resemblance,” says Comstock, “that they have been mistaken for galls by many entomologists.”
Species of Lecanium, a genus of coccids found everywhere on plants, attack basswood, tulip tree, maples, and many other trees, covering the leaves with a sweet liquid similar to that yielded by plant-lice. In California a scale-insect (Lecanium oleae) covers the foliage of citrus fruit trees with great quantities of shining dew. A fungus often grows luxuriantly on such leaves, forming a dense felt over their surface. At Amherst, Mass., and Guelph, Canada, thousands of bees have been observed gathering from spruce trees the sweet excretions of a scale-insect (Physokermes piceae). They are found at the base of new growth, and have the appearance of little buds. Pine trees are likewise at times prolific sources of honey-dew gathered from scale-insects living at the base of the leaves (Fig. 6).
Probably more honey-dew is produced by plant-lice or aphids (Aphididae) than by any other family of insects. They occur on a great variety of herbaceous plants, trees, and shrubs, more than 450 species being listed. A part of the species live on the leaves, a part on the limbs, and others on the roots. Among the decid-