78 R. W. CROSSKEY 



1966 : 893) of the name Microphthalmina (based on Microphthalma Macquart). 

 However, as neither name has yet become established, and as it seems almost cer- 

 tain that Dexiosoma will in future be regarded by specialists as synonymous with 

 Microphthalma, it is preferable to use the name Microphthalmini in the hope that 

 this will become the accepted tribal name. 



In the past the members of this tribe were classified amongst the Proseninae 

 (Dexiinae), which they resemble in external facies and host relations, but Verbeke 

 (1 962ft) has rather conclusively shown that the affinities lie not with the 'Dexiines' 

 but with the Tachininae (Echinomyiinae of Verbeke), at least as demonstrated by 

 the structure of the male genitalia. The tribe is small but widely distributed in 

 the major zoogeographical regions, with the apparent exception of the Australasian 

 Region: it appears on present evidence to be naturally absent from New Guinea, 

 Australia, New Zealand and the other Pacific islands, although its natural distribu- 

 tion in the Oriental Region certainly extends eastwards as far as Celebes and Timor. 

 The characteristic head form by which the Microphthalmini are easily recognized 

 is shown in Text-figs 40 & 68 and the wing venation in Text-fig. 94. 



The Oriental fauna includes both Dexiosoma and Microphthalma. The latter 

 genus has not previously (so far as I know) been recorded from the Oriental Region, 

 but whilst preparing the present work I have seen specimens of Microphthalma 

 in the BMNH collection from 'India' and Ceylon and through the kindness of 

 Dr Shima have been able to see specimens of the genus collected recently in different 

 parts of Indonesia (Flores, Lombok, Celebes, Timor). (All the specimens, except 

 that from 'India' which is M. europaea Egger, appear to represent an undescribed 

 species and to be conspecific with African specimens misidentified by past authors 

 as europaea.) 



The genera Dexiosoma and Microphthalma are in reality so closely allied that 

 separate generic status is only very doubtfully justified, and it is interesting to 

 note that Curran (1928ft : 379) long ago gave it as his opinion that the two are 

 synonymous - a view to which specialist opinion will almost certainly return when 

 the whole complex is thoroughly revised on a world basis. In the meantime I am 

 following Mesnil (1974 : 1233) and recognizing separate genera, as there is no difficulty 

 in differentiating Dexiosoma and Microphthalma so far as the Oriental fauna is 

 concerned. On a world basis differentiation is more difficult because some species, 

 or individuals within species, that on aggregate of characters pertain to Microphthalma 

 actually show characteristics that are typical of Dexiosoma (e.g. possess three 

 instead of four post dc setae, three instead of two stpl setae, and lack either or 

 both the prst ia seta and the pra seta) . The only notable adult character that 

 might serve consistently to distinguish the two genera is the presence in the female 

 sex of a pair of very strong outwardly directed prevertical setae in Dexiosoma 

 and their absence in Microphthalma (a feature already noted by van Emden 

 (1947 : 671)), but an unsupported secondary sexual character of this kind can 

 scarcely warrant generic weighting. The conclusion I come to is that the two 

 genera should not be maintained when the tribe, in future, is comprehensively 

 studied but should be merged into a redefined and enlarged Microphthalma. 



Scarabaeid beetle grubs, sometimes of economically important species, provide 



