. The Acarina or mites. A review of the group for the use of economic entomologists. Mites. of these organs is not fully known, but the sacculus contains spermatocysts which are supposed to reach it through the annulate tubes. Some, if not all, of the Parasitidae have a most remarkable method of coition, which Michael has discovered and described in detail. The male, which is commonly a little smaller than the female, clasps the latter by the legs of one side and crawls under her. His abdomen extends back beyond that of the fe- male, and he grasps her with his legs. Then a clear sac emerges fr
. The Acarina or mites. A review of the group for the use of economic entomologists. Mites. of these organs is not fully known, but the sacculus contains spermatocysts which are supposed to reach it through the annulate tubes. Some, if not all, of the Parasitidae have a most remarkable method of coition, which Michael has discovered and described in detail. The male, which is commonly a little smaller than the female, clasps the latter by the legs of one side and crawls under her. His abdomen extends back beyond that of the fe- male, and he grasps her with his legs. Then a clear sac emerges from the genital aperture of the male, gradually enlarging until it is of full size and shape, which is constant for each species. Usually this sac or bubble is flask-shaped, with a long neck. It incloses the spermatozoa floating in a clear viscid liquid (sometimes within spermatocysts). The male clasps this bubble with his mandibles, which are often modified apparently for such purpose. The male then applies the small end of the bubble to the vulva of the female, often inserting his mandibles for some distance. Here the small end of the bubble bursts and the liquid and spermatozoa are discharged into the spermatheca of the female. The bubble is rather firm, and when empty does not collapse, but shrinks somewhat. After the male leaves the female he proceeds to clean his mandibles. In those species in which the female has no spermatheca, but has annulate tubes connecting to the acetabula of the third pair of legs, it is probable that the bubble is ap- plied to these apertures and not to the vulva, the sperma- tozoa thus passing into the sacculus fsemineus, from which they may pass into the ovary as occasion demands. In the male of one species there is a hole in the jaw, through which the bubble is pushed, part hanging on either side. Trouessart has claimed that in Raillietia there is a true parthenogenesis; agamic generations are found in spring and summer, the male appearing only
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherwashi, bookyear1915
