. Diptera Brachycera. Brachycera. XYLOMYIA. 97 two joints short, subequal, 3rd with eight ambulations and usually a very small apical bristle. Thorax oval and subquadrate, slightly arched ; scutellum unspined. Abdomen longer than thorax and about as wide, 7-segmented ; genitalia distiuct. Legs rather long, simple, except for the slight incrassation of the femora, especially the hind pair, which are considerably thickened in some species and often with a row of small spines on underside ; posterior tibiae with two spurs. Wings longer than abdomen, not of the normal Stratiomyid type ; veins not
. Diptera Brachycera. Brachycera. XYLOMYIA. 97 two joints short, subequal, 3rd with eight ambulations and usually a very small apical bristle. Thorax oval and subquadrate, slightly arched ; scutellum unspined. Abdomen longer than thorax and about as wide, 7-segmented ; genitalia distiuct. Legs rather long, simple, except for the slight incrassation of the femora, especially the hind pair, which are considerably thickened in some species and often with a row of small spines on underside ; posterior tibiae with two spurs. Wings longer than abdomen, not of the normal Stratiomyid type ; veins not crowded together anteriorly, all distinct aud attaining wing-margin ; costal vein reaching wing- tip ; ambient vein present for some distance ; 2nd vein beginning distinctly before base of discal cell, 3rd vein, originating shortly after, the fork elongate, the lower branch ending at wing-tip ; discal cell much more elongate than in any other subfamily; 4th vein with three terminations, the lowest one closing the 4th pos- terior cell at wing-border; posterior cross-vein very short or absent; anal cell closed distinctly but not considerably before wing-border ; alar squamse small, thoracic pair Fig. 8.—Xylomyia, wing. Range. Europe, the Orient, North, Central, and South America, Canary Isles, and Natal. Life-history. Larva amphipneustic (though Luudbeck doubts if it is truly so), broad, brown, leathery, with parallel sides, upper and lower surfaces with bristles placed transversely on segments, 12-segmented, including head, which is broadly conical; mouth- parts normally Stratiomyid ; last body-segment semicircular ; oritice of respiratory chamber forming posterior extremity of body. It lives in old trees or decaying wood. Xylomyia is a genus of yellow and black, rather Ichneumon-like flies, with considerable outward resemblance to Xylophagus (LEPTiDiE), but the closed 4th posterior cell will easily distinguish them. The species seem to be much rarer in the adult than
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Keywords: ., bookcentury1900, bookcollectionbiod, bookdecade1920, bookyear1920
