COCCIDÆ.
[Footnote: A paper recently read before the California Academy of Sciences.]
By DR. H. BEHR.
With the exception of Hymenoptera there is no group of insects that interfere in so many ways in good and evil with our own interests, as that group of Homoptera called Coccidæ.
But while the Hymenoptera command our respect by an intellect that approaches the human, the Coccus tribe possesses only the lowest kind of instinct, and its females even pass the greater part of their lives in a mere vegetation state, without the power of locomotion or perception, like a plant, exhibiting only organs of assimilation and reproduction.
But strange to say, these two groups, otherwise so very dissimilar, exhibit again a resemblance in their product. Both produce honey and wax.
It is true, the honey of this tribe is almost exclusively used by the ants. But I have tasted the honey-like secretion of an Australian lecanium living; on the leaves of Eucalyptus dumosus; and the manna mentioned in Scripture is considered the secretion of Coccus manniparus (Ehrenberg) that feeds on a tamarix, and whose product is still used by the native tribes round Mount Sinai.
Several species of Coccides are used for the production of wax; many more, among which the Cochenill, for dyes.
All these substances can be obtained in other ways, even the Cochenill is to a great extent superseded by aniline dyes, but in regard to one production, indispensable to a great extent, we are entirely dependent on some insects of this family; it is the Shellac, lately also found in the desert regions around the Gila and Colorado on the Larrea Mexicana. You will remember that excellent treatise on this variety of Shellac, written by Professor J.M. Stillman at Berkeley, on its chemical peculiarities.