. The black scale. Scale insects. Bulletin 223] THE BLACK SCALE. 18' another in 44 days; another in 46 days, and another in 50 days. On this basis there would be 4 generations from May to October, inclusive. From November to April, on account of the slower development during the winter months there will be from 2 to 3. While there may be thus a total of 6 or 7 generations a year, on account of the unfavorable condition of the host, 4 or 5 will be nearer the actual number. HYPERPARASITE. Cerchysius sp. Under the old black scales there will be occasionally found, instead of the characteristic Sc
. The black scale. Scale insects. Bulletin 223] THE BLACK SCALE. 18' another in 44 days; another in 46 days, and another in 50 days. On this basis there would be 4 generations from May to October, inclusive. From November to April, on account of the slower development during the winter months there will be from 2 to 3. While there may be thus a total of 6 or 7 generations a year, on account of the unfavorable condition of the host, 4 or 5 will be nearer the actual number. HYPERPARASITE. Cerchysius sp. Under the old black scales there will be occasionally found, instead of the characteristic Scutellista pupa, a black or brown oval or torpedo- shaped body that may at first be mistaken for a dipterous puparium. This will be found to be the old larval skin of the Scutellista larva dis- tended and harboring a parasite within this parasite. This has been taken from several different sections, including Whittier, Glendale. Pomona, Santa Paula, and Santa Barbara. But it is found most abund- antly at Santa Barbara, where in certain groves the percentage of Scu- tellista attacked ran between 5 and 10 per cent. THE LARVA. The larva of this hyperparasite is white in color, length 2 mm., greatest width nearly 1 mm., 13 segments, broadest at head end and. Fig. 12.—Hyperparasite on the Scutellista, Cerchysius sp. gradually tapering toward the posterior. Very similar in color and shape to that of its host. On the head segment of the larva of Scutellista there is present above, and later ad of the mouth, two blunt horns or spines. These are absent on the larva of Cerchysius. This larva com- pletely consumes the contents of the Scutellista larva, leaving only the outside epidermis. This is changed to a leathery texture, and to a dark. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Quayle, H. J. (Henry Josef), 1
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscalein, bookyear1911
