Guide to the Study of Insects and a Treatise on Those Injurious and Beneficial to Crops: For the Use of Colleges, Farm-schools, and Agriculturists

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Holt, 1876 - 715 páginas
 

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Página 544 - This disease among the chinch bugs was associated with the long-continued wet, cloudy, cool weather that prevailed during a greater portion of the period of their development...
Página 519 - Early in the ensuing spring, as soon as the sap begins to flow, these eggs are hatched, and the young lice immediately begin to pump up sap from the tender leaves and shoots, increase rapidly in size, and in a short time come to maturity. In this state it is found that the whole brood, without a single exception, consists solely of females, or rather and more properly, of individuals which are capable of reproducing their kind. This reproduction takes place by a viviparous generation, there being...
Página 242 - Dresden, is to squeeze out the intestines through a hole made near the anal extremity of the larva, then to insert a fine straw, after which it may be put in a glass vase, itself placed in a tin vessel and held over a lamp ; the larval skin is blown while suspended over the lamp, by which the skin dries faster. It may be done with a small tube or blow-pipe fixed at the end of a bladder, held under the arm or between the knees...
Página 643 - So, also, how they deposit their eggs, and the form and appearance of the silken nidus, and whether the female bears her eggs about her, and how this is done, whether holding on to the egg-sac by her fore or hind legs, should all be carefully noticed. Care must be taken not to mistake the young for full-grown, mature species, and describe them as such.
Página 506 - It is only one sixteenth of an inch long, of a black color, with clay-yellow antennae and legs, except the hindmost thighs, which are brown. The upper side of the body is covered with punctures, which are arranged in rows on the wing-cases ; and there is a deep transverse furrow across the hinder part of the thorax.
Página 327 - The fore-wings are marbled with gray beyond the middle, and have a distinct oblique gray spot on the tip ; they are crossed by two wavy blackish lines, one near the middle, and the other near the outer hind margin ; these lines are formed by little elevated black tufts, and there are also two similar tufts on the middle of the wing. The hind wings are dusky brown or light brown, with a paler fringe, and are without bands or spots.
Página 554 - Rhynchota [Hemiptera, bed-bug, etc.] generally in the circumstance that the labium is capable of being retracted into the upper part of the head, which therefore presents a little fold, which is extended when the labium is protruded. In order to strengthen this part, a flat band of chitine is placed on the under surface, just as...
Página 343 - ... (Clemens) ; or the moths may be collected in pill boxes, and then carried home and opened into a larger box filled with fumes of ether or benzine or cyanide of potassium. In pinching any moths on the thorax, as is sometimes done, the form of that region is invariably distorted, and many of the scales removed. In searching for "Micros...
Página 80 - Homoptera (allied to the tree-hoppers), ants of two different genera, and a poorly preserved moth. Perhaps a minute Thrips, belonging to a group which has never been found fossil in any part of the world, is of the greatest interest.
Página 344 - Thus a glass jar, tumbler or jam-pot, the top of which has been ground to receive an air-tight glass cover, and the bottom covered with moist white sand, will keep a leaf fresh for a week, and thus a larva in the summer will have to be fed but two or three times before it changes ; and the moth can be seen through the glass without taking off the cover ; or a glass cylinder can be placed over a plant inserted in wet sand, having the top covered with gauze. Dr.

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