Page:Popular Science Monthly Volume 38.djvu/146

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THE POPULAR SCIENCE MONTHLY.

has given rise to similar lines of development, starting from types having more or less in common. The discussion was so satisfactory to the section that a committee was appointed to consider upon the selection of a subject for a similar series of papers at the next meeting.

Insect Aid for our Orange-growers.—Bulletin No. 21 of the Division of Entomology is entitled Report of a Trip to Australia, made under Direction of the Entomologist to investigate the Natural Enemies of the Fluted Scale. Mr. Koebele, the divisional agent who makes the report, acting under instructions from Prof. Riley, and aided by funds through the State Department, and the courtesy of Hon. Frank McCoffin, Commissioner-General to the Melbourne Exposition of 1888-89, sailed for Australia in August, 1888, where he remained until March of the succeeding year, collecting and making shipments to California of the parasites of the fluted scale. No little difficulty was experienced in finding sufficiently large colonies of the scale to obtain enough specimens infested with parasites, as the latter, aided by other enemies, have reduced and nearly exterminated the scerya in Australia. A large number of a small dipterous parasite were shipped, but, as this is a slow breeder, its work has been eclipsed by a small lady-bird which was afterward discovered and comprised the major part of the later shipments. This ladybird, called the Vedalia, has done such good service that the fluted scale is now practically overcome in California, and orange growers have again taken heart. The report deals besides with injurious insects observed during Mr. Koebele's stay in the country, among the most notable being the orange and olive scales, and a scale known as Monophlæbus, remarkable for its immense size, being larger than any heretofore known. All of these scales are highly injurious, and figures accompany the descriptions of them, besides which is mentioned and figured a snout beetle imported from the Mediterranean region, which is very injurious to the young shoots and leaves of the olive. In addition to the dipterous parasite (Lestophonus) and the Vedalia before mentioned, as forming the bulk of the shipments for California, there were also included a number of other beneficial predatory insects. These were several small coccinellids of the genera Scymnus, Coccinella, Rodolia, and Zeis, all of which are more or less important as scale-destroyers. As a rival of the last there were brought over about a hundred larvæ of a noctuid moth (Thalpochares cocciphaga), which is a most efficient scale-eater in its larva state and promises to become a valuable adjunct to our other introduced scale enemies. The work, however, of the lady-bird (Vedalia cardinalis) has been so very effective that the other species have been kept in the background and probably driven to the wall. Within a year after its introduction the Vedalia had practically exterminated the Icerya and given a renewed impulse to orange culture in California. Great credit is due to Prof. Riley for the scientific work that has secured this important result.

The Tarantula.—The tarantula, says A. J. Field, in Knowledge, is one of the largest but not the most venomous species of spiders found in Europe. It is one of the Lycosidæ, or wolf-spiders, is about three quarters of an inch long, and is covered all over its body with an olive, dusky-brown down. During the summer months, while creeping among the corn, it bites people employed in the fields, but the bite, though painful, is seldom dangerous. According to Dr. Zangrilli, the part bitten becomes deadened soon afterward, and in a few hours there are slight convulsive shiverings, cramps of the muscles, and spasm of the throat, followed by vomiting and a three days' fever. Recovery generally follows after a copious perspiration, but in one case there was tetanus and death on the fourth day. The tarantula is common in Spain, southern France, and Italy, where it occurs in great numbers in Apulia round the town of Taranto. It has been found in Asia and in northern Africa. It lives in dry places, partly overgrown with grass and fully exposed to the sun, in an underground passage which it digs for itself and lines with its web. These passages are round, sometimes an inch in diameter, and extend to the depth of a foot or more below the surface. This spider is very quick in its movements, and eager in the pursuit of