. Citrus fruits; an account of the citrus fruit industry, with special reference to California requirements and practices and similar conditions . igrate far from the parent scale unlessthe food supply is scarce or the feeding surface dry and hard,in which case they may travel several feet. The scaly cover-ing which the young insect ])egins to form over itself as soonas it is settled is simply for protection, and is not a part ofthe body, as in the case of the half grown black scale. Itconsists of a mass of light cottony threads secreted by theyoung scale; later this is enlarged by the two cas
. Citrus fruits; an account of the citrus fruit industry, with special reference to California requirements and practices and similar conditions . igrate far from the parent scale unlessthe food supply is scarce or the feeding surface dry and hard,in which case they may travel several feet. The scaly cover-ing which the young insect ])egins to form over itself as soonas it is settled is simply for protection, and is not a part ofthe body, as in the case of the half grown black scale. Itconsists of a mass of light cottony threads secreted by theyoung scale; later this is enlarged by the two cast-off skinsof the growing larvae. lender this protection, they con-tinue to feed until mature, which requires from two and a halfto three and a half months. The mature female scale isreddish in outward appearance and about the size of thehead of an ordinary pin. The mature male scale is smallerand more elongated than the female. The male sheds itsskin four times and emerges as a winged insect in from oneand a half to two months. Although each female produces but from forty to eightyyoung, the fact that in southern (California there are four. Fig. 141. — Work of red .scale on orange413 414 Citrus Fruits generations during the season accounts for tlieir rapid in-crease. The same agents responsible for the spread of theblack scale also disseminate the red scale. The internal parasites of the red scale do not seem to be atall effective in reducing their numbers, as only a small per-centage of the scales are parasitized. Several species of theladybird beetles are commonly found attacking the redscale, but are not of much assistance in their control. Fumi-gation according to the schedule given in Chapter XXIIIis the most effective remedy. Yelloio Scale (Ckrysomphalus aurantii var. citrinus) The yellow scale is but a variety of the red scale, and isidentically the same in structure. It is somewhat yellow incolor, although the color becomes much darker after theinsect dies, when it i
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectcitrusfruits, bookyea
