. Cirtus fruits under irragation. Citrus fruits; Fruit-culture. Fig. 17 § 28 CITRUS FRUITS IN GULF-COAST STATES 23 These parasitic fungi, although more abundant in the sum- mer than at other times, are more apt to work throughout the wmter than those that are parasites of the white flies and thev are even more efficient in keeping down the scales. So impor- tant are these parasitic fungi that if they are destroyed as happens when the trees are sprayed with Bordeaux mixture to kill injurious fungi, the purple scales at once increase to such an extent as to severely damage or even kill the trees
. Cirtus fruits under irragation. Citrus fruits; Fruit-culture. Fig. 17 § 28 CITRUS FRUITS IN GULF-COAST STATES 23 These parasitic fungi, although more abundant in the sum- mer than at other times, are more apt to work throughout the wmter than those that are parasites of the white flies and thev are even more efficient in keeping down the scales. So impor- tant are these parasitic fungi that if they are destroyed as happens when the trees are sprayed with Bordeaux mixture to kill injurious fungi, the purple scales at once increase to such an extent as to severely damage or even kill the trees unless prompt measures are taken. If it is absolutely necessary to spray the trees with Bordeaux mixture or other similar fungicide, the grower must follow it soon with an insecticide or there will surely be trouble with the purple scales. The grubs of a wasp-like insect also aid in the control of the puri^le scale. The wasp-like insect lays its eggs in the scales, and the eggs hatch out into white grubs that consume the scale insects and their eggs and then change to the adult wasp-like form and escape through a round or oval hole in the top of the scale. The ladybird beetles, of which the twice-stabbed ladybird beetle is the most important, are another aid in the control of the purple scale, as they eat large numbers of the crawlers. The mature form of the ladybird beetle is shown at the left in Fig. 19, and at the right on twigs are shown empty pupa cases from which the beetles have crawled. 21. The mxthods of control for the pun:)le scale are much the same as those practiced for the control of the white flies Fumigation, spraying with the heavy oils, and the introducing and spreadmg of the parasitic fungi, will tend to hold the purple scales m check. Fumigation for the purple scale alone is not used m the Florida citrus belt except on nursery stock. The. Fig. 18. Please note that these images are extracted from scanned page images that may have been digitally enhanced for
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Keywords: ., bookcentury1900, booksubjectcitrusfruits, booksubjectfruitcultur
