. Elementary entomology. Entomology. PRESERVING AND STUDYING INSECTS ;57 completed, it may be temporarily sealed by covering with a glass plate which is firmly pressed in position. The glycerin has many distinct advantages over water, its density holding the more delicate structures in position, and at the same time it has a higher index of refraction. Plates of vari- ous sizes and depths may be easily con- structed to meet different requirements. Rearing insects. If one wishes to study the life history of insects, or if desirous of procuring especially fine specimens, by far the best method i
. Elementary entomology. Entomology. PRESERVING AND STUDYING INSECTS ;57 completed, it may be temporarily sealed by covering with a glass plate which is firmly pressed in position. The glycerin has many distinct advantages over water, its density holding the more delicate structures in position, and at the same time it has a higher index of refraction. Plates of vari- ous sizes and depths may be easily con- structed to meet different requirements. Rearing insects. If one wishes to study the life history of insects, or if desirous of procuring especially fine specimens, by far the best method is to rear them under artificial conditions. In this work an at- tempt must always be made to simulate natural conditions as closely as possible. There is less liability of the larvae being parasitized if they are placed in a breed- ing cage when quite small. Numerous breeding cages have been constructed for the purpose of rearing larvae. Of these, one of the best is shown in Fig. 493. This consists of a frame with a glass door on one side, the other three sides being covered with cheesecloth. If possible, the food plant is placed in a flowerpot inside the breeding cage. If this is impracticable, twigs and branches can be placed in the cage in bottles of water, the top of the bottle being stuffed full of cotton to prevent the lar- vae from drowning. Another simple breed- ing cage for smaller insects is made b}- placing a lantern globe or lamp chimney, the top of which is covered with a square of cheesecloth, over the food plant (Fig. 494) in a flowerpot. The food material should be changed frequently, so that it may be kept fresh and sufficient. For rearing large quantities of larvae an open tray three by five feet is most convenient. (After washbum). Fig. 494. A lamp-chimney breeding cage (After Banks). 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
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Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912