. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 82 THE SCOLYTID BEETLES. GENERATION. The overwintered broods of adults begin to attack the trees, exca- vate galleries, and deposit eggs about the first of August and continue to do so during August and September, until October or later, but the principal period of attack is in August. The larvae begin to hatch early in August and begin to transform to pupae and adults in Septem- ber and October. Under favorable conditions a few adults may emerge late in the fall, but evidently it is the normal habit for the. Fig
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 82 THE SCOLYTID BEETLES. GENERATION. The overwintered broods of adults begin to attack the trees, exca- vate galleries, and deposit eggs about the first of August and continue to do so during August and September, until October or later, but the principal period of attack is in August. The larvae begin to hatch early in August and begin to transform to pupae and adults in Septem- ber and October. Under favorable conditions a few adults may emerge late in the fall, but evidently it is the normal habit for the. Fig. 45.—The mountain pine beetle: Egg galleries and larval mines in bark. Reduced. (Author's illustration.) broods of this generation to pass the winter as all stages of larvae, as adults in pupal cases, and as parent adults, and it is evident that some individuals of the delayed broods do not complete their development until in the fall of the year following and that some of them pass the second winter as parent and young adults. There is, therefore, but one generation annually, with a possible overlapping of the generations of three years during the 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 United States. Bureau of Entomology. Washington : G. P. O.
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