. Injurious insects and the use of insecticides [microform] : a new descriptive manual on noxious insects, with methods for their repression . greatly, and, as we shall soon see, serve asa basis for their classification into twowidely differing groups. As the period of pupation, or of changefrom the larva to the pupa approaches,some insects spin a cocoon in which to passthe dormant pupal stage, some form aboutthemselves a covering of leaves tightlydrawn together, some are covered by ahard pupal casing, while others that de-scend into the earth, or that are subterra-nean in their habits during
. Injurious insects and the use of insecticides [microform] : a new descriptive manual on noxious insects, with methods for their repression . greatly, and, as we shall soon see, serve asa basis for their classification into twowidely differing groups. As the period of pupation, or of changefrom the larva to the pupa approaches,some insects spin a cocoon in which to passthe dormant pupal stage, some form aboutthemselves a covering of leaves tightlydrawn together, some are covered by ahard pupal casing, while others that de-scend into the earth, or that are subterra-nean in their habits during the larvalperiod, hollow out cells in the earth inwhich the quiescent stage is passed. Indue season come forth perfect insects, morewonderful in their metamorphoses than thetransformations of the nymphs of Diana as told in mythic Fig. 4—Cocoox of CeceopiaEmperor. INSECTS, CLASSIFICATIONS, AND INSECTICIDES. 21 The imago usually lives but a short time—but for a few days or afew weeks —just long enough to fulfil the one function of its life, which ^f^i§?r^
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectbenefic, bookyear1894