. California greenhouse pests and their control. Insect pests; Greenhouse plants. mine within the leaf tissues, forming an irregular blotch. As they mature, they emerge, curl over a portion of the leaf with silken threads, and feed on the inner surface. The transformation stage is formed where they have been feeding. Important Greenhouse Species Azalea leaf miner, Gracilaria azaleella Brants. Adults are prettily marked with bright purple and yellow. The caterpillars commonly infest greenhouse azaleas, but they do not appear to build up under lath house or garden conditions. CONTROL Both lead a
. California greenhouse pests and their control. Insect pests; Greenhouse plants. mine within the leaf tissues, forming an irregular blotch. As they mature, they emerge, curl over a portion of the leaf with silken threads, and feed on the inner surface. The transformation stage is formed where they have been feeding. Important Greenhouse Species Azalea leaf miner, Gracilaria azaleella Brants. Adults are prettily marked with bright purple and yellow. The caterpillars commonly infest greenhouse azaleas, but they do not appear to build up under lath house or garden conditions. CONTROL Both lead arsenate and nicotine or other plant product preparations are re- ported to give effective control. Certain of the newer insecticides appear to be preferable, however. 1. DDT: excellent control. (See page 52.) 2. Parathion: excellent control. (See page 57.) LEAF TIERS Importance: The leaf tiers belong to a group of caterpillars which are often im- portant feeders on plants. Only one species, however, is found ordinarily in greenhouses. Appearance: The caterpillars are pale in color, about 3/4 inch long when grown. They are generally found within leaves which are folded over or tied together for protection. The moths are somber colored, about 1/2 inch long when at rest. The wings are held along the sides to give a triangular appearance. Development: Eggs are laid singly or in small groups on the underside of leaves. They hatch in 1 or 2 weeks. The caterpillars feed almost entirely on the underside of leaves, chewing off the sur- face in irregular patches when they are young and eating holes when they are larger. The larval stage lasts about three weeks. The transformation stage occurs. Fig. 43. Azalea leaves showing damage by the azalea leaf miner. r 331. 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 Pritcha
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Keywords: ., bookcentury1900, booksubjectgreenhousepl, booksubjectinsectpests
