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The Onychia was frequently observed ovipositing in fresh dung apparently at random. A. musca was bred from puparia of Diptera, but with no positive evidence of its being reared from those of Hamatobia. This species, however, was perhaps the most abundant of the parasites bred from the dung, and it is very likely that it will be ascertained to be a true horn fly parasite as well as a foe to other dung-feeding Diptera. We have figured it at Plate IV, Fig. 2.

Several species of beetles, Staphylinida, were observed to frequent the dung and to feed on the eggs of Diptera, particularly on the egg-masses of the common blue-bottle ily (Lucilia cæsar). The eggs of the latter were drawn out and quickly eaten or sucked and the empty shells discarded. These beetles were not observed to attack the larvæ.


The abundance of the horn fly during the summer of 1889 and its general scarcity during the summer of 1890 afford another of the common instances in insect increase and decrease. The influence of climate not only upon the insect itself but upon its natural enemies must be considered as the main factor which produces this result. The summer of 1889, it will be remembered, was marked by an extraordinary and almost continuous rainfall, while the precipitation in the summer of 1890, though great, was much less. Breeding, as this insect does in dung, it is plausible to suppose that its chances for successful transformation will be better in dung kept continually moist than in dung which dries at once. Should this supposition, which we are quite inclined to believe, be correct, the 1889 abundance and the 1890 scarcity are readily explained. The insect is so new as a stock plague, however, that the experience of future seasons must decide whether, as now seems likely, the species will be scarce in seasons of drought and numerous in summers when the precipitation is abundant.

The very commonest of the Dipterous insects which breed in cow dung through Virginia was found to be the common blue-bottle fly (Lucilia cesar). `In many fields Mr. Howard found that almost every dung dropped the previous day contained oneor more clusters (a hundred or more eggs in a cluster) of the elongate white eggs shown at Plate VII, Fig. 2 a, b, c, d. They were almost invariably hidden from view and had evidently been laid after the dung had dried sufficiently to become a little hard on top. The eggs had then evidently been thrust into a crack and placed in little erect bunches beneath the surface. There is no danger that this insect will ever be mistaken for the horn fly in any of its stages except that of the young larva. The eggs are comparatively slender and much longer than those of the horn fiy, and the full-grown larva and the puparium are twice as large as the corresponding stages in the latter insect. The young larva, however, may be distinguished by the lack of the ridged lamellar structure of the head, so noticeable in the corresponding stage of the horn fly. From abundant material brought in by Mr. Howard it was ascertained that an entire generation of the bluebottle fly averages in midsummer from ten to fourteen days in duration. The numbers in which the adults issue from the dung are almost inconceivable--every morning for several days the breeding cage was apparently full of a swarming mass of flies.


[Plate I.)

No person living in the State of California will for an instant doubt the importance of carefully studying the habits and characters of any new species of the now well-known genus Icerya. Up to the present year but two species of this genus have been known. The one is the sugar-cane pest of Mauritius (the Pou blanc of the French planters), scientifically known as Icerya seychellarum Westwood, or 1. sacchari Signoret, and the second is the now celebrated fluted scale of California (Icerya purchasi), to which we have devoted so much attention during the past four years and which has occupied many pages in annual reports prior to this one.

During the present year no less than four new species have been added to the two already known. One of these has been described by Mr. J. W. Douglas as Crossotosoma ægyptiacum, but upon careful study we have concluded that it should be more properly placed in the genus Icerya. It may be popularly called the Egyptian Icerya. The other three have been editorially described in INSECT LIFE under the names: Icerya rosce, the rose Icerya; Icerya montserratensis, the Montserrat Icerya, and Icerya palmeri, Palmer's Icerya. The full technical descriptions of these new species will be found in INSECT LIFE Vol. III, No. 3, pages 94 to 105, and need not be repeated here.

The rose Icerya was sent to us last March by Passed Assistant Paymaster H. R. Smith, U. S. Navy, from Key West, Florida, on a limb of rosebush, with information that rosebushes on the Key were greatly troubled by the insect, which caused the stems to dry and the leaves to fall. It seems to infest other trees, inoluding the sugar apple, lime, and lemon. We have shown the adult insect and its appearance upon rose on Plate I, Figs. 1, 2, and 3.

The Egyptian Icerya occurs in the gardens of Alexandria, Egypt, appearing first on the Banyan tree and spreading to many other plants. It has killed off many trees and has caused great alarm. A striking peculiarity of the species is the possession by the female of long waxy projections which shower down from the trees when a breeze is blowing.

The Montserrat Icerya occurs upon the Island of Montserrat, West Indies, and infests there a species of Chrysophyllum, known to the inhabitants of the island as Galba or Galaba tree. It is also stated to occur, though less abundantly, upon fig and citrus trees. This species resembles the Egyptian Icerya in the possession of the long waxy projections. (Plate I, Figs. 4 and 5.)

Palmer's Icerya occurs upon grape in the Province of Sonora, Mexico, where it was collected by Dr. Edward Palmer in 1887. Thé specimens received occurred upon the grape leaves along the main ribs and principally along the under sides in great numbers. Dr. Palmer found only one variety of grape infested, namely, the Muscat of Alexandria. (Plate I, Figs. 6 and 7.)

There is danger that this last species and the one occurring in Montserrat may some day make their appearance within our boundaries, and the fruit growers of Florida should take all possible pains to prevent such introduction. They would be justified in quaran. tining against plants from the West Indies until authoritatively

Report of the Entomologist US Dept of Agriculture 1890

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