BLOOD-SUCKING MUSCID^E 603 



Family. Leptidae. 



[This widely distributed family of flies has a few species which suck the blood of 

 man, and the writer has been personally badly bitten in Norway by a Leptis which 

 was apparently Leptis scolopacea. 



[The Leptidce have usually blotched wings and similar venation to Tabanus ; they 

 are elongated flies of moderate or large size, and of dull colours. The antennae are 

 varied and consist of three segments, either with or without a terminal bristle or with 

 the third segment compound, and in a few they may be almost nematocerous. The 

 wing veins are distinct, very crowded anteriorly, the third long vein is furcate, basal 

 cells large, and there are usually five posterior cells, the anal cell being open in some ; 

 the squamae are always small, sometimes only rudimentary. 



[Four are known to be blood-suckers, namely the American Symphoromyia, 

 Trichopalpus obscurus in Chili, and Leptis strigosa and L. scolopacea in Europe. 

 The genus Symphoromyia has a single spur on the hind tibiae, none on the fore or. 

 mid tibiae, the third segment of the three-ringed antennae kidney-shaped, and a short 

 proboscis. In the genus Leptis the hind tibiae have two spurs, and the third antennal 

 segment is not reniform. 



[The other biting genus Trichopalpus can be told at once by the elongated 

 proboscis. Most of this family live upon other insects. The larvae live in earth, 

 decaying wood, sand, stagnant waters, and the nests of wood-boring beetles ; they 

 are usually cylindrical and may have fleshy abdominal legs ; the anal segment has 

 a transverse cleft, and often two posteriorly directed processes and two stigmata 

 between them. They are all predaceous, and in one genus (Vermileo) make pitfalls 

 in sand like the ant lions (Myrmeleoii). 



Blood - sucking 1 Muscidae. 



[The blood-sucking Muscidce are mainly contained in the following genera : 

 Glossina, Stomoxys, Haematobia, Lyperosia, Stygeromyia, Philaematomyia and 

 Bdellolarynx. 



[The first is the most important genus on account of the part it plays in the 

 spread of trypanosome diseases. Stomoxys may also serve as a disease carrier. 

 The remainder and a few more genera cause considerable annoyance by their 

 bites, and may also act as occasional carriers of pathogenic organisms. All these 

 flies have their mouth parts elongated to some extent, forming a distinct proboscis, 

 which becomes more or less strongly chitinized ; the labella are usually serrated 

 or spiny, and thus form a structure easily capable of piercing the skin. Unlike 

 the CulicidcB) the blood-sucking Muscidcs have the sanguinary habit common to both 

 sexes. 



Genus. Glossina, Westwood. 



[This genus contains sixteen species, 1 all of which are confined to the Ethiopian 

 region. Glossina may be distinguished from other allied genera by the proboscis, 

 the antennae, wings, and male genitalia. The proboscis projects forwards and has 

 i swollen bulb-like base to the slender labium which holds the two structures, the 

 needle-like epipharynx and the thread-like hypopharynx ; the whole proboscis is 



1 This does not include G. maculata, Newstead, which is regarded by Austen as a 

 synonym of G. palpalis, Rob. Des. ; according to this authority the curiously spotted 

 ippearance of the type and only example of G. maciilata is due to foreign matter. 



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