TACHINIDAE OF AUSTRALIA n 



bend of vein M. The forward curvature or angulation of the median vein (M) 

 where the bifurcation of M t and M 2 occurs, or if there is no bifurcation then 

 the part of M where a forward change in its general direction occurs before it 

 attains the wing margin (cubitidus) (Text-figs 10 & n). 



The nature of the bend can be of great taxonomic importance (e.g. in 

 differentiating the Blondeliini with an open gently curving bend from the 

 Exoristini with a sharply angulate bend). A few Tachinidae lack the apical 

 part of the vein (i.e. Mj) and there is therefore no bend, and some very rare 

 aberrant forms have only a very slight forward inclination of .1/. 



cell R b . The wing cell distal to cross-vein r-m and enclosed by vein R i + & anteriorly 

 and veins M and A/ x posteriorly (apical cell) (Text-figs 10 & n). 



An important taxonomic character is provided by this cell and its associated 

 venation according to whether it is 'open' or 'closed'. If the veins -K 4 + 5 and 

 M x reach the wing margin separately from each other then cell R 5 reaches to 

 the wing edge (Text-fig. 10) and is open; but when veins i? 4 + 5 and M x coalesce 

 and form a short common stalk ('petiole') before reaching the wing margin the 

 cell is isolated from the edge of the wing and is closed (Text-fig. n). In the 

 latter case the cell is described as 'petiolate' (prefixed 'long-' or 'short-' if 

 desirable). Intermediate forms occur in which the cell is closed just at the wing 

 margin. 



The cell is open in the vast majority of Goniinae, Tachininae and Proseninae, 

 but is commonly closed and long-petiolate in Phasiinae (e.g. Alophora, 

 Cylindromyia, Leucosioma, Euthera). 



cerci. The inner median pair of articulated processes attached to the epandrium 

 of the male hypopygium (mesolobes, inner forceps, anal forceps) (Text-fig. 21). 



Conformation and degree of fusion of the cerci have some taxonomic importance, 

 but relatively little at supraspecific level. 



costa. The strong vein forming the fore margin of the wing. 



costal sector. A segment of the costal length between any two successive veins 

 that end at the costa. 



costal spine. A short strong seta on the costa at the apex of vein Sc , inserted 

 immediately before the costal 'break'. 



Usually undeveloped or very inconspicuous, if strong then normally not 

 exceeding r-m in length. Taxonomic value mainly at specific level. 



cross-vein tn-cu. The most distal wing vein connecting veins M and C« x (posterior 

 cross-vein, hind cross-vein, m-m, M 3 ) (Text-figs 10 & 11). 



The position at which m-cu joins M (whether mid-way between r-m and the 

 bend or nearer to the latter than the former) and the obliqueness of the vein 

 have some taxonomic importance (e.g. in Voriini the cross-vein is exceptionally 

 oblique in relation to the long veins and the wing in this tribe has a distinctive 

 appearance on this account). 



cross-vein r-m. The very short length of vein connecting veins R i + 5 and M 1 and 

 closing cell R 5 at its base (anterior cross-vein, R6) (Text-fig. 10). 



In itself of no taxonomic use but a reference point for determining length 

 proportions on the long veins. 



