. Annual report. New York State Museum; Science. INSECTS AFFECTING PARK AND WOODLAND TREES 323 anal fork black tipped. Thoracic feet blackish, marked with black. Body unicolorous, immaculate, or the orange spots of the next stage partly present (another brood). 4th stage. Head shining black, the front with four grooves and two dents above the clypeus ; sutures around the mouth brown ; width mm. Thoracic feet large, pale olive, marked with black; abdominal ones small, on joints 6-11, 13, pale green. Body smooth, irregularly 5-annulate, the creases like slight folds ; shining blackish, oliva
. Annual report. New York State Museum; Science. INSECTS AFFECTING PARK AND WOODLAND TREES 323 anal fork black tipped. Thoracic feet blackish, marked with black. Body unicolorous, immaculate, or the orange spots of the next stage partly present (another brood). 4th stage. Head shining black, the front with four grooves and two dents above the clypeus ; sutures around the mouth brown ; width mm. Thoracic feet large, pale olive, marked with black; abdominal ones small, on joints 6-11, 13, pale green. Body smooth, irregularly 5-annulate, the creases like slight folds ; shining blackish, olivaceous, with a series of lateral pale orange spots, distinct only centrally. The spots are above the subventral fold on annulates 2 and 3. Larxae vary in shade, some are blacker than others, and the orange spots vary in distinctness. The larvae scratch the leaf with their anal prongs and make a rasp- ing sound. 5th stage. Width of head mm. As before, slaty black, except the feet; lateral orange patches on joints 3-12; the two median annulates have somewhat corneous, dorsal, trans- verse areas, shining, but concolor- ous with body. Feet all pale watery. Two days after molting the larvae began to turn shining and livid and with a pale dorsal streak anteriorly and entered the ground to spin their cocoons. The adult insect is brownish, black, marked with yellowish white and measures about I3 inch in length. Life history. The first indications of the presence of these slugs on willow, according to Dr Howard, is seen in peculiar blisterlike swellings on the upper surface of the foliage, which sometimes give it a wavy or crumpled appearance. Investigation shows that these swellings are occa- sioned by the presence of oval, whitish eggs partially inserted in the under surface of the leaf substance. Black spots and streaks appear about the time hatching begins, four to eight days after oviposition, the effect of. Please note that these images are extracted from scanned page image
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectscience, bookyear1902
