Half hours with insects . -, theybelong to families which also contain closely allied generawhich live in the earth. For example, most crane fly larvaeare terrestrial, a few are adapted for aquatic life ; some lar-val horse flies live in mould, some are known to be aquatic; 8 Packakd] tNTSECTS OF THE POND AND STREAM. 137 most of the Syrphidae are Aphis-eaters in the larval that immense family MuscitUe, of which the house fly isa t3pe, which are almost purely terrestrial, Eplndra (, fly and pupa case) is aquatic. It may be said on thewhole that the aquatic larvie of the Diptera w
Half hours with insects . -, theybelong to families which also contain closely allied generawhich live in the earth. For example, most crane fly larvaeare terrestrial, a few are adapted for aquatic life ; some lar-val horse flies live in mould, some are known to be aquatic; 8 Packakd] tNTSECTS OF THE POND AND STREAM. 137 most of the Syrphidae are Aphis-eaters in the larval that immense family MuscitUe, of which the house fly isa t3pe, which are almost purely terrestrial, Eplndra (, fly and pupa case) is aquatic. It may be said on thewhole that the aquatic larvie of the Diptera were originallyterrestrial insects, which have adopted an aquatic life andare exceptions to the rule. In the Neuroptera, however, there are whole families whichare aquatic both in the larval and pupal state, having exter-nal gill-like appendages in both stages, and in the case of Fig. Pteronarcys, which is closely allied to Perla (Fig. 99, fromFiguier), they are retained in the winged fly. The Neurop-tera arc par excellence water insects, and yet it is doubtfuleven whether they have not originally assumed this excep-tional mode of life, and, while the earliest of all insects, werenot at first terrestrial. This is speculation and guesswork,but facts seem to point to this conclusion. Now the changes in structure fitting the insect for a lifein ponds and streams are to be found in the organs of loco-motion and the breathing apparatus, and in this essay I 9 138 HALF HOURS WITH INSECTS. [Packard. Fig. 100.
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectinsects, bookyear1881
