52 R. W. CROSSKEY 
Ameniamima includes all the species of Rutilia s.l. in which the suprasquamal 
ridge is bare and there are more than three postalar setae (elsewhere in Rutilia s.l. 
the few species with bare ridge have only three postalars). The metallic green or 
blue colouring that is typical in Ameniamima, combined with the bright orange- 
yellow head, give the species a superficial resemblance to some Chrysorutilia species, 
and it is possible that it is to this latter subgenus that Ameniamima is most closely 
related; the two subgenera share such features as the presence of four or five postalar 
setae, the haired area of the lower pteropleuron extending well forwards of the 
level of the posterior sternopleural seta, the presence of a definite irregular transverse 
row of semi-horizontal preapical scutellar setae in front of the marginals, similar 
general shape of facial carina, and similar lack of a definite median depression in the 
last abdominal tergite (though a small depression is present at the tip of the tergite 
in Ameniamima males). The main differences between Ameniamima and Chryso- 
vutilia, apart from the bare suprasquamal ridge in the former and densely haired 
ridge in the latter, include the following: parafacials, prosternum and prosternal 
membrane bare in Ameniamima (partly or entirely haired in Chrysorutilia) ; inner 
half of humeral callus with one or two humeral setae developed in addition to the 
pair on the outer half of the callus in Ameniamima (only the outer pair present in 
Chrysorutilia) ; hind tibia usually without definite fringe in Ameniamima (with long 
close-set regular fringe in Chrysorutilia); abdominal T5 with long strong setae in 
Ameniamima (only with fine hairing in Chrysorutilia, except for some weak erect 
bristling in Philippine forms). In addition the chaetotaxy is generally much stronger 
in Ameniamima than in Chrysorutilia, especially the bristling of the mesonotum, 
the outermost humeral setae, and the posterodorsal setae of the hind tibia. The 
head of Ameniamima species is almost entirely thickly yellow pollinose over the 
yellow ground colour, only the extreme upper parts of the occiput being bare or | 
metallic, and the completely pollinose genal dilations and postbuccae will at once | 
distinguish specimens of the subgenus from Chrysorutilia (in which all species have 
these areas of the head largely bare or metallic and at most only thinly pollinose). 
The body colour in Amenianuma ranges from brilliant metallic green (sometimes 
with brassy or coppery tinge) to blue, violet and purplish black; in one species, 
cingulata, the colour is virtually black except for violet tinges near the pollinose spots 
and metallic silvery blue colour underlying a thick whitish pollinosity on abdominal 
T3. All the species possess well developed, conspicuous and rather discrete, spots 
of thick white pollinosity, those of the abdomen having a slightly shifting appearance 
with the light. The spot pattern consists of paired white spots in these positions: 
humeral; supra-alar; mesopleural; sternopleural; ventrolateral on abdominal T3, 
T4, and T5; dorsolateral on T3; submedian on T4 and T5. In addition there is 
usually a pair of submedian white pollinose vittae variously developed on the 
prescutum, and in a few specimens (including the lectotype of argentifera) there is a 
trace of an evanescent pair of submedian spots on T3. Usually the dorsolateral 
spots of T3 and the submedian spots of T5 are more or less merged with the ventro- 
lateral spots of their respective tergites. In the male of cingulata, which conforms 
to the basic plan of the pattern, the supra-alar spots and the submedian spots of 
T4 and T5 are rather small but the white pollinosity is so extensively developed on 

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