Page:Popular Science Monthly Volume 86.djvu/271

Rh scale pest had got carried to America without its vedalia enemy, and, accordingly, found California in truth the promised land. Now what more common-sensible than deliberately to import and colonize vedalia in the California orange and lemon orchards? Which was, accordingly, done, and done easily and successfully, so that here, as in Australia, vedalia keeps the cottony-cushion scale insect within practically harmless bounds.

Naturally such a success has led to many other attempts in many other similar cases. Perhaps no other success has been so marked as the now classic first one, but much other success there has been, both on the Pacific coast and on Pacific islands, notably Hawaii, and also in the eastern states. The great fight against the imported foliage and forest tree pests of New England, the direful gipsy and brown-tail moths, is resolving itself more and more into a search for and colonizing of their natural parasites in Europe and Japan.

Another type of good bug brought to the Pacific coast by deliberate importation and carefully nursed to an effective colonization is the curious little fig-wasp, Blastophaga, by whose means the "caprification," i. e., pollination, of figs depends, on which depends, in turn, the full size, sweetness and the nutty flavor of the best commercial figs. The fig is a hollow but fleshy receptacle with many minute flowers inside. The Blastophaga eggs are laid in the ovules of these flowers, and there the tiny grub (larva) lives and feeds and changes finally into a little chrysalid, and then adult. The adult male Blastophaga is a curious deformed wingless creature, and remains in the fig of its birth until it dies. But the female is a winged active insect that leaves its natal and cradle fig and flies to others to lay its eggs. Curiously, it can find suitable egg-laying places only in the wild or so-called capri figs and so does not leave eggs in the cultivated figs, but in walking about over their flowers it dusts them with pollen brought from the fig last visited, and thus produces the necessary cross-pollination. As the Blastophaga lays no eggs in the domestic figs, it is necessary to keep a few wild fig-trees growing in or near the orchard.

But not all the Pacific coast insects are excessively bad bugs or excessively good ones. Some call for attention because they are just beautiful, or singular, or of unusual habit or habitat. And these are likely to seize the interest of most of us more certainly than the pests. For, after all, our interest in nature is not primarily one of dollars and cents. It is one of curiosity and of "wanting to know."

A matter that lends California's fauna and flora a special interest to naturalists is the peculiar biogeographic situation of the state. Biologically, California is essentially a large island, shut off by barriers of actual water on one side and by hot desert and high cold mountain ranges on the other, with the ends also nearly similarly barred by desert