1. THEREVA 553 



to the lower part. Antennae with the basal joint covered with greyish yellow 

 dust and with fine pale tawny pubescence on its basal part and the usual stiff 

 black bristles on its apical part, but these bristles not so numerous nor so 

 strong as usual ; second joint with numerous short black bristles ; third joint 

 blackish brown, and bearing a tiny black dorsal bristle near its base ; style 

 short. 



Thorax dark brown, with two distinct but inconspicuous widely separated 

 tawny stripes which extend its whole length ; pleurae ashy grey. Pubescence 

 almost erect and mainly black on the disc, but foxy red all round the margin, 

 and when viewed from in front this foxy red pubescence appears to be even 

 more abundant and to be interspersed (though shorter than the black hairs) 

 on the disc; chastotactic bristles as in fig. 311, but with five or six unequal 

 pnesutural bristles and sometimes a trace of a second praescutellar bristle 

 on one or both sides ; pleurae with abundant foxy red pubescence (slightly 

 paler than that on the sides of the dorsum), and with the dense tufts on the 

 mesopleurae and metapleurae very conspicuous and including no black hairs 

 except a few at the hinder upper corner of the metapleural tuft. Scutellum 

 with long dense tawny pubescence and the usual black marginal bristles. 



Abdomen more conical than in T. nohilitata and T. plebeia, deep velvety 

 black with bright orange bands ; the deep black colour occupying the basal 

 segment except at the sides, a spot on the second segment beginning on about 

 the middle half of the base but narrowing somewhat triangularly down to the 

 orange hindmarginal hem, the basal two-thirds of the third segment (and 

 even more about the middle but less than half on the sidemargins), the basal 

 two-thirds of the fourth, fifth, and sixth segments even to the sidemargins, 

 and sometimes the seventh and eighth segments ; the hindmarginal hems 

 broad and clear orange on the second segment, and narrower but still bright 

 orange on the third and fourth segments, but becoming lost in the greyish 

 orange bands on the fifth and sixth segments ; greyish orange bands lie 

 between the bright orange hindmarginal hems and the black base of the 

 segments or lie on the hindmargins themselves and the one on the second 

 segment is almost interrupted at the middle but widens out at the sides (in 

 conjunction with the bright orange hindmarginal hem) until it may occupy 

 the whole of the sidemargins, and the one on the third segment is obscurely 

 narrowed at the middle but widens out slightly at the sides to rather more 

 than half the sidemargins, while the one on the fourth segment does not widen 

 out at all ; the greyish orange bands on the fifth and sixth segments occupy 

 the hindmarginal third of each segment. Pubescence very conspicuously 

 bright rufous orange but with a fairly broad black dorsal stripe which forms a 

 series of slight crests because the hairs droop just before (and overhang) each 

 bare hindmarginal hem ; the bright rufous orange pubescence diminishes in 

 length and density on the fourth and fifth segments, and the whole pubescence 

 becomes mainly black on the sixth segment, and all black but rather longer 

 again on the seventh and eighth segments, and almost forming a tuft about 

 the base of the seventh segment. Belly shining black, with conspicuous 

 broad pale orange hindmarginal hems on the second, third, and fourth 

 segments, and with a narrow hem on the fifth segment ; pubescence on the 

 second to fifth segments remarkably long and thin, though not at all dense, in 

 fact almost sparse, black on all the seventh segment, and partly black but 

 mainly riifous orange on the eighth segment. Genitalia with a pair of 

 upraised blackish lamellae, and near them with a pair of lurid red narrow 

 lamellae which bear some pale orange hairs on the inner side, and with two 

 subquadrate blackish plates beneath which bear some reddish orange hairs at 

 their end margins. 



Legs black, but the tibiae blackish red except rather broadly at their tips, 

 and the base of the first tarsal joint (and more on the middle pair) obscurely 

 reddish orange. Pubescence on the anterior coxae tawny and so dense that 

 the usual strong black bristles are almost hidden, but on the hind coxae 

 shorter and less dense and mainly black ; on the front femora the pubescence 

 behind and beneath is densely matted and dull black, and the black 

 pubescence may extend even more but usually the pubescence on the upper 

 part is mainly yellow ; on the middle femora it is similar but less niatted ; 

 while on the hind femora it is i^ale and fairly conspicuous but is limited to 



