ENTOMOLOGY

SANITARY ENTOMOLOGY.!legment and the extremity of the twelfth, there are delicate finger-likeprocesses, usually four in number, which serve as tracheal gills. Thepupa is free and either lives floating in water without any movement orrests on the bottom of the pool. It has a tuft of delicate white threadson the dorsum of the thorax, which serve as breathing tubes; or it mayhave a pair of respiratory trumpets.Ter8e8the8 torren8 Townsend, a mountain form in North America, isa voracious bloodsucker, a.ttacking man and animals, usually on the head,ears, and eyes. Its life history is unknown. .Mycterotypu8 bezzii and M. irritan8 of Southern Europe are voraciousbloodsuckers, biting human beings, as well as animals, and causinginflammatory swellings.Ceratopogon is a large genus containing a number of bloodsuckinggnats called "punkies," found in various parts of the world. Some of theAsiatic species attack bloodsucking mosquitoes and draw blood fromthem. It is therefore possible that these insects may playa role in diseasetransmission. They are very small, measuring Jess than S mm. in length.Only the females are bloodsuckers. They bury themselves often amongthe hairs of the host and are not recognized until they become repletewith blood. They often cause great distress on account of their numbersand the irritation produced by their bites. The different specieschoose different parts of the host for '!,ttack, as for example, some selectthe face, especially the margins of the ears and eyes, while others mayattack the arms or legs.Forcipomyia utae Knab is thought by Townsend to cause the SouthAmerican disease, uta. Forcipomyia is c(:>Dsidered to be a subgenus ofCeratopogon. Larva: have been found in crab holes and below the algalcrust on the sand along the seashore in South America.Culicoides is another large genus of midges very similar to Ceratopogon,and contains many bloodsuckers. Only the females bite. Thelarva: are found in water under various conditions. When searching forlarva: where the adults are abundant, they may be found by gatheringin a white tray some of the green vegetable matter found at the edges ofstreams. The flies can be bred by placing the pupre on moist filter paperin tubes closed with moist cotton.The genera Johannseniella and Haematomyidium also contain bloodsuckingmidges.FAMILY SIMULIIDAEBuffalo GnatsThe buffalo gnats of the genus Simulium are sometimes also calledsand flies and turkey flies. This is a large genus of voracious flies whichoften are so numerous as to cause great distress and even death to men