Handbook of medical entomology . They undergo incom-plete metamorphosis, when the young insect, as it leaves the egg,resembles the adult to a greater or less extent, and after under-going a certain number of molts becomes sexually mature. Representatives of several orders have been reported as accidentalor faculative parasites of man, but the true parasites are restrictedto four orders. These arc the Siphunculata; the Hemiptera, theDiptera and the Siphonaptera. Siphunculata The order Siphunculata was established by Meinert to include thetrue sucking lice. These are small wingless insects, with
Handbook of medical entomology . They undergo incom-plete metamorphosis, when the young insect, as it leaves the egg,resembles the adult to a greater or less extent, and after under-going a certain number of molts becomes sexually mature. Representatives of several orders have been reported as accidentalor faculative parasites of man, but the true parasites are restrictedto four orders. These arc the Siphunculata; the Hemiptera, theDiptera and the Siphonaptera. Siphunculata The order Siphunculata was established by Meinert to include thetrue sucking lice. These are small wingless insects, with reducedmouth-parts, adapted for sucking; thorax apparently a single piecedue to indistinct separation of its three segments; the compound eyes Sipkunculata, or Lice 8i. 64. Pediculus showing the blind sac (6) containing themouth parts (a) beneath the alimentary canalip). After Pawlowsky. reduced to a single ommatidium on each side. The short, powerfullegs are terminated by a single long claw. Metamorphosis incom-plete. There has been a great deal of discussion regarding the structureof the mouth-parts, and the relationships of the sucking lice, and the questions cannot yet be re-garded as settled. The con-flicting views are well repre-sented by Cholodkovsky(1904 and 1905) and byEnderlein (1904). Following Graber, it isgenerally stated that themouth-parts consist of ashort tube furnished withhooks in front, which consti-tutes the lower lip, and that within this is a delicate sucking tubederived from the fusion of the labrum and the mandibles. Opposedto this, CholodlcA^osky and, more recently, Pawlowsky, (1906), haveshown that the piercing apparatus lies in a blind sac tmder thepharynx and opening into the mouth cavity (fig. 64). It does notform a true
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectinsectp, bookyear1915
