Half hours with insects . e stores of vitalized food about it; and on the other handthe parasite must carefully avoid touching the vital parts ofits host. It must content itself with feeding upon the fattyportions alone of the body. That family of the Hymenoptera of which the ichneu-mon-fly (Fig. 4) is a type, and many species of true flies 15 HALF nOURS WITH ESTSEGTS. [Packakd. (Fig. 5) bearing a close resemblanco to the common house-fly, are devoted to this work of process is thus: the parent fly lays its eggs within orupon the body of its victim, most commonly a
Half hours with insects . e stores of vitalized food about it; and on the other handthe parasite must carefully avoid touching the vital parts ofits host. It must content itself with feeding upon the fattyportions alone of the body. That family of the Hymenoptera of which the ichneu-mon-fly (Fig. 4) is a type, and many species of true flies 15 HALF nOURS WITH ESTSEGTS. [Packakd. (Fig. 5) bearing a close resemblanco to the common house-fly, are devoted to this work of process is thus: the parent fly lays its eggs within orupon the body of its victim, most commonly a caterpillarwhich is full-grown and about to enter upon its transforma-tions. The young worm hatches and feeds upon the largestores of fatty tissues which surround the vital organs of itshost. How very nice must be the adjustment of relationsbetween the two animals, when in the case of the parasite,the slightest deviation from its path involving any injuryto the neighboring nerves or vessels of its host will bring Fig. Tachina and larva. eventual ruin to itself b}^ hastening the death of the cater-pillar ! This delicate balance between the growing parasiteand wasting victim may continue through the chrjsalidstate of both insects, until just as we think the butterflywill break its prison walls, lo ! the trim, neat form of itsunrelenting enemy steps forth from its body ready armedand equipped for active service. The late Mr. Ilerrick some years ago announced the dis-covery of the fact that the eggs of the canker worm werepreyed upon by a minute ichneumon-fly. Here is an anom-aly—an egg nourishing its inhabitant and immersed in the 16 Packakd.] INSECTS OF THE GARDEN. 17 contents of another egg! We have had the pleasure ofwatching the labors, late in autumn, of this little insect,whose length measures not over three hundredths of an inch,as it was busily engaged upon a bunch of eggs under ourobject glass, Avith a restless anxiety to rid itself of its burdenof infinitesimal eg
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectinsects, bookyear1881
