Bulletin of the Illinois State Laboratory of Natural History, Volume 11

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The Laboratory., 1915 - Natural history
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Page 254 - Catalog of the exhibit of insect enemies of forests and forest products at the Louisiana Purchase Exposition, St. Louis, Missouri.
Page 162 - ... and lodging — two or three Coleoptera — a Psocus (Pseudoneuroptera) — a Heteropterous insect found abundantly in several other willow-galls — an Aphis which is also found on the leaves of the willow, but...
Page 254 - Insect Enemies of the Pine in the Black Hills Forest Reserve. An Account of Results of Special Investigations, with Recommendations for Preventing Losses. Prepared under the direction of the Entomologist. By AD Hopkins, Ph. D., Vice-Director and Entomologist of the West Virginia Agricultural Experiment Station.
Page 134 - Another case almost exactly similar is reported by Mr. Barlow. In this instance the building of a dam resulted in the submerging of the ground about an oak tree during several months of every summer, ultimately resulting in the death of the tree. This went on for several years, until the dam was washed away by a freshet, when digging beneath the tree led to the discovery of the Cicada larvae in apparently healthy condition from 12 to 18 inches below the natural surface of the ground.
Page 135 - Cicada larvae in apparently healthy condition from 12 to 18 inches below the natural surface of the ground. In both of these instances the ground may have been nearly impervious, so that the water did not reach the insects nor entirely kill all of the root growth in the submerged soil.
Page 91 - ... especially during the warm season of the year when the surface of the soil is heated. Soil covered only with a dead vegetable cover evaporates moisture much more slowly than a bare soil or an open water surface. On the other hand, a soil with a living vegetal cover loses moisture, both through direct evaporation and absorption by its vegetation, much faster than bare, moist soil. The more highly developed the vegetal cover the faster is moisture extracted from the soil and given off into the...
Page 155 - ... resting stage, or pupa, which transforms to the adult beetle. Often all stages, from very young grubs only about one-fourth inch long to full-grown grubs over 1 inch long, pupae, and adults in all stages to maturity are present in the same pole. Adults have been found flying from July to September. The insect attacks poles that are perfectly sound, but will work where the wood is decayed ; it will not, however, work in wood that is "sobby" (wet rot), or in very "doty
Page 93 - ... conditions of temperature, pressure, porosity, and concentration of carbonic acid. (8) We have compared the linear velocities of diffusion and barometric transpiration, and hence — (9) We have shown that the escape of carbonic acid from the soil and its replacement by oxygen take place by diffusion and are determined by the conditions which affect diffusion, and are sensibly independent of the variations of the outside barometric pressure.
Page 162 - ... but scarcely ever penetrating into the central cell, so as to destroy the larva that provides them with food and lodging — two or three...
Page 136 - ... vegetation must have been entirely removed. An instance of a few weeks acceleration under outdoor conditions is given by Mr. Schwarz." Commenting on the slightly earlier emergence of individuals of Brood XIV near Harpers Ferry, W. Va., in 1889, in a small clearing surrounded by woods, Mr. Schwarz urges that a clearing made in the midst of a dense forest forms a natural hothouse, the soil receiving in such places much more warmth than in the shady woods. That the cicadas should appear a little...

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