70 



CHAPTER XII. 



DIPT ERA APHA NIPT ERA. 



DIPTERA Characters The Proboscis Structure Metamorphosis Internal Anatomy Habits Parasitism Distribution 

 Classification TRIBE NEMOCERA THE CULICIDJE, OR GNATS Metamorphosis Habits Blood-thirstiness 

 The Mosquito Other Gnats THE CHIRONOMIM; THE TIPULID^E THE CRANE FLIES, or Daddy Long-legs The 

 Giant Crane Fly The Genus Ctcnophora Midges Other Genera THE MYCETOPHILID.E Fungus Midges The Army 

 Worm THE CECIDOMYIP.E, or Gall Midges The Hessian Fly Its Destructiveness The Wheat Midge Another Post 

 The Galls Dr. N. Wagner's Observations on the Genus Jtfiastor THE PSYCHODIIXE THE BIBIOXIDJE "Garden 

 Flies" " Sand Flies" The Columbatsch Fly TRIBE NOTACANTHA THE STRATIOMYID.E TRIBE TANYSTOMA 

 THE TABANID/E, or Breeze Flies, or Gad Flies Habits The Ox Breeze Fly The Golden-eyed Breeze Fly The 

 CLEGG A " Blood-drinker" THE ASILID.E THE THEREVID.E THE EMPID.E THE ACROCERID.E THE BOMBYLIID.-E 

 --THE LEPTID.E THE DOLICHOPODID.E THE PLATYPEZID.E THE SCENOPINID.E TRIBE ATHERICERA THE 

 SYRPHID.E Parasitism The Volucella- The Genus Eristalis THE MusciDvE Characters The Tachinarice The 

 Muscariee The Common House Fly -The Bluebottle The Flesh Fly The Greenbottle Flies The Tsetse Fly The 

 Acaliipterce Various Genera The Phorides The CEstrides The (Estrus bovis The Cephalomyite Gastrus TRIBE 

 PUPIPARA THE HIPPOBOSCIIXE THE NYCTKKIBIID.E THE BRAULID/E APHANIPTERA, THE FLEAS 

 Characters Classification Transformations Habits Various Species Their Muscular Energy Trained Fleas The 

 Jigger Its Pernicious Parasitism. 



THE Diptera agree with the Lepidoptera in having a suctorial mouth and a perfect meta- 

 morphosis, but differ from them in so many particulars that there is no difficulty in distinguishing 

 them in fact, the order is one of the best characterised in the whole class of insects. They -may be 



defined as insects with a perfect metamorphosis 

 and a sucking mouth ; with the prothorax ring- 

 shaped and all the segments of the thorax united 

 into a mass ; with only two wings, which are 

 membranous, naked, or more or less hairy, 

 attached to the mesothorax, while the hind 

 wings are represented by a pair of small 

 knobbed organs called halteres. These char- 

 acters of the wings will serve to distinguish 

 the Diptera at once from the Hymeiioptera. 

 with some of which certain species of flies 

 might be confounded at the first glance. 



The mouth, althoiigh a sucking organ in 

 the strictest sense of the term, differs completely 



from that of the Lepidoptera in the nature of the modifications by which its parts 

 are adapted to their peculiar functions, and especially in the fact that, whereas the 

 actual proboscis of the Lepidoptera is formed by a single pair of the fundamental 

 organs of the mouth, that of the Diptera may include and bring into action the 

 whole of those parts. The visible proboscis itself is composed of the lower lip 

 (labium), which may be either horny or fleshy in its textm-e, and is often capable 

 of bending a little way from its base, and of being retracted within a cavity of the 

 under surface of the head. It varies greatly in length, being sometimes quite short 

 and easily concealed, sometimes very long, even much longer than the whole body. 

 The tip is sometimes more or less pointed, sometimes blunt, and then often ter- 

 minated by a pair of fleshy lips forming a sort of cleft disc, in the middle of 

 which the aperture of the mouth is situated. This structure may be well seen in 

 the common House Fly, or the Meat Fly. But whatever may be its external pecu- 

 Jiarities, the proboscis consists of the labium produced into a more or less tubular 

 form, and cleft more or less widely along the upper or front surface. This cleft is 

 closed by the labrum or upper lip, which is elongated so as to reach towards the tip of 

 the proboscis, and, although considerably narrower than the labiurn, is also curved 

 into the form of a half tube with its concavity turned towards that of the labium. 



Within the tube of the proboscis we find several bristles, often flattened and of a lancet shape, 

 the office of which is to penetrate the tissues of plants and animals, and set free the juices upon which 



DIPTEROUS INSECTS VOLUCELLA PELLUCENS AND 

 CERIA CONOPSOIDES. 



HEAD OF FEMALE 

 GNAT. 



rynx; m,' mandibles; 

 V, maxilla:; p, palpus. 



