Smithsonian miscellaneous collections . bdomen with large dorsalprongs. Though the adult of the species has not been certainly identi-fied, no adult mirid is known to possess any such armature. Among the Homoptera there is a distinct though sporadic tendencyfor the young insect to develop special characters of its own that arenot carried over into the adult stage, or to take on a form quitedifferent from that of its parents. The aberration of the young insectmay even become so pronounced that the final transformation to theimago approaches or actually attains a condition of holometabolism. no.
Smithsonian miscellaneous collections . bdomen with large dorsalprongs. Though the adult of the species has not been certainly identi-fied, no adult mirid is known to possess any such armature. Among the Homoptera there is a distinct though sporadic tendencyfor the young insect to develop special characters of its own that arenot carried over into the adult stage, or to take on a form quitedifferent from that of its parents. The aberration of the young insectmay even become so pronounced that the final transformation to theimago approaches or actually attains a condition of holometabolism. no. 9 INSECT METAMORPHOSIS—SNODGRASS 39 A good example of simple metamorphosis in the Homoptera isseen in the structural adaptation of the young cicada to a subterraneanlife by the modification of its front legs for digging (fig. 6D). Thenymphal structure of the leg is not present in the embryo (A) ; itappears first on the nymph with the shedding of the embryonic cuticlejust after hatching (B) and becomes more fully developed in succes-. Fig. 6.—Examples of simple juvenile metamorphic characters in Hemiptera. A, Magicada scptemdecim (L.), newly hatched nymph still in embryonic cuti-cle. B, same, left front leg of first instar (from Marlatt, 1923). C, same, frontleg of third instar, mesal vieiw showing reduced tarsus (Tar). D, same, front legof mature nymph, lateral. E, same, front leg of adult. F, Paracarnus myersiChina, nymph, Heteroptera-Miridae (from China, 1931). sive instars (C,D). The tarsus of the first instar (B) is reduced inlater stages to a small spur on the inner surface of the tibia (C,Tar),but it is fully restored in the mature nymph (D). At the transforma-tion to the adult, the special features of the nymphal leg are muchreduced or obliterated (E). The newly hatched cicada has a pair ofsmall eye spots, but in subsequent instars the eyes are lost, and func-tional compound eyes are redeveloped only in the imago. Within achamber just below the surface of the ground
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