. Cirtus fruits under irragation. Citrus fruits; Fruit-culture. b2 CiTKUtS l^RUiTS UNDER IRRIGATION §24 the young pistil or the developing orange, scraping off the epidermis. Their presence in the grove can usually be told by their work on the fruit, the surface of which is scarred. Often a ring like that shown in Fig. 29 is found around the stem end. At times they work down from this ring in streaks. Later the blossom end is attacked, but the marking at this end is less distinct than at the stem end. These growths do not injure the edible qualities of the fruit, but such fruit must, on accoun
. Cirtus fruits under irragation. Citrus fruits; Fruit-culture. b2 CiTKUtS l^RUiTS UNDER IRRIGATION §24 the young pistil or the developing orange, scraping off the epidermis. Their presence in the grove can usually be told by their work on the fruit, the surface of which is scarred. Often a ring like that shown in Fig. 29 is found around the stem end. At times they work down from this ring in streaks. Later the blossom end is attacked, but the marking at this end is less distinct than at the stem end. These growths do not injure the edible qualities of the fruit, but such fruit must, on account of its appearance, be classed as low grade. In addition to the fruit, the leaves and tender growth of the tree are attacked; in a badly infested tree, the growth is injured. Two species of thrips are responsible for much damage to citrus fruits in California and Arizona. These are the regular citrus ihrip and the greenhouse thrip. 48. The adult cit- rus thrip is a very small four-winged in- sect about ih to -h inch long and too inch wide. Fig. 30 is an illustration of the adult thrip. The color ranges from dark brown to almost black. The insects can also be recognized by their ability to jump great distances in proportion to their size when distiu-bed. Under a lens, the wings are seen to consist of a true membrane fringed on all free sides by hairs, which are several times longer than the width of the membrane. Adults of this species occur in early spring and there is a succession of broods up to November. The thrips spend the winter in the adult form, hibernating in a protected place. In the spring, about May, the adults appear and begin depositing eggs in cracks in the tissue on which they feed. The eggs hatch in about 6 to 10 days from the time they are deposited. The larvas have no wings but in other respects they closely resemble the adults. In from 6 to 8 days they pass into the pupal stage, from which they. Fig. 30 § 24 CITRUS FRUITS UNDER IRRIGATION 53 emerge as adu
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