. Insects injurious to forests and forest products. e strong mandi])les of the larva. Here the restingstage (fig. 3), or pupa, is formed, and in this chamber the perfect adultspends considerable time before emerging. Often all stages from veryyoung larvje only about one-fourth inch long to full-grown larvae over 1 inch long, pupae, andadults in all stages tomaturity are present inthe same pole. Adultshave been found flyingfrom July to Septem-ber. As yet the sea-sonal history of thisborer has not been com-pletely worked out. DISTRIBUTION. Fig. 2.—The chestnut telephone-pole borer: Female beetle
. Insects injurious to forests and forest products. e strong mandi])les of the larva. Here the restingstage (fig. 3), or pupa, is formed, and in this chamber the perfect adultspends considerable time before emerging. Often all stages from veryyoung larvje only about one-fourth inch long to full-grown larvae over 1 inch long, pupae, andadults in all stages tomaturity are present inthe same pole. Adultshave been found flyingfrom July to Septem-ber. As yet the sea-sonal history of thisborer has not been com-pletely worked out. DISTRIBUTION. Fig. 2.—The chestnut telephone-pole borer: Female beetle, three ims insect IS Veiy and one-half times natural size. Head and pronotiim of male widely distributed beetle. (Original). ranging from Ontario, Canada, to Texas, eastward to the Atlantic coast, and westward toArizona and southern California. It is common throughout thenatural range of the chestnut—and in this connection it should beobserved that most of the chestnut poles are purchased from localtimber-land owners. CHARACTER OF THE The injury to the poles consists in large mines in the wood near theline of contact of the pole with the ground, necessitating the frequentresetting or even the replacement of the damaged poles. Theseirregular galleries of the grub (Plate II, fig. 1) run both horizontallyand longitudinally throughout the heartwood, and are sometimes 7inches long, but vary with the individuals, which show great chfFer-ences in size. The borers usually work in the outer layers of thewood at the base of the pole for a distance of from 2 to 3 feet below,and sometimes from 1 to 2 feet above the line of contact of the polewith the surface of the ground. The greatest damage is to that areajust below and just above the surf ace of the ground (Plate I, fig. 3);here the conditions of air and moisture are most favorable. Oftenthe entire butt up to a distance of from 4 to 6 feet and higher,according to the depth of setting, is mined. The numerous galleries,often
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectelectri, bookyear1910
