108 M. W. R. de V. GRAHAM 



Holotype $. England : unlegalized, Cooke coll., BM(NH). 



Paratypes. England : Berkshire, Wytham Wood, i $, 29.viii.1962 ; Bucking- 

 hamshire, Hell Coppice, near Oakley, 1 $, 27.viii.1959 (Graham), coll. Graham. 

 Czechoslovakia : Bohemia, Hradec Kralove, 1 $ (/. Gekina) ; Praha-Revnice, 

 1 $ reared from Polyporus, vii.1953 (L. Masner), (BM(NH)). 



Biology. Unknown. 



PLATYGERRHUS Thomson 



Platygerrhus Thomson, 1878 : 4, 13. Type-species : P. gracilis Thomson, by monotypy. 



Platygerrhus Thomson 



Platygerrhus Thomson 



Platygerrhus Thomson 



Platygerrhus Thomson 



Platygerrhus Thomson 



Platygerrhus Thomson 



Platygerrhus Szczepariski, 1961 : 3-1 1. 



Platygerrhus Thomson ; Peck, 1963 : 750. 



Platygerrhus Thomson ; Peck et al., 1964 : 35. 



Ashmead, 1904 : 284, 285. 



Schmiedeknecht, 1909 : 156, 157, 169. 



Nikol'skaya, 1952 : 213. 



Boucek, 1954 : 67. 



Kerrich & Graham, 1957 : 300-303. 



Ferriere & Kerrich, 1958 : 30. 



Kerrich & Graham (1957 : 300) recognized only two European species of Platy- 

 gerrhus, viz., dolosus (Walker) and ductilis (Walker). Even at that time I had some 

 reservations regarding the number of species, which I felt might well be greater. 

 Since then I have studied much new material, as a result of which I now recognize 

 more species and have to make some changes in the synonymy. Although the 

 females of Platygerrhus are in general rather difficult to separate, the males often 

 show good characters in their antennae. In some cases, however, recognizably 

 distinct males have not yet been associated with any female. Hence it is very 

 desirable to breed the species carefully in order to correlate the sexes in all of them ; 

 if any worker could perform this task it would be an invaluable contribution to 

 knowledge of this group. 



Key to European Species 

 (Females) 



1 Propodeum between the spiracles, the callus, and the metapleuron, with strong 



raised reticulation (hence relatively dull) ; all these parts green to blue. 

 Metapleuron with three to ten hairs. Gena often smooth in the neighbour- 

 hood of the malar sulcus. Fore wing sometimes with a fuscous cloud below 

 the stigmal vein ; basal cell open below in at least its proximal half ; row 

 of hairs on lower surface of costal cell often incomplete. (Species-group of 

 maculatus Erdos) .......... 2 



— Propodeum between the spiracles with sculpture which is weaker than that of 



the callus and metapleuron, and green to blue in colour ; callus and 

 metapleuron varying from bronze to coppery and violet, area around each 

 spiracle nearly always blue to violet. Metapleuron most often bare, very 

 occasionally with one or two hairs. Gena entirely reticulate, or with at 

 most a very narrow smoother strip running along the malar sulcus. Fore 

 wing immaculate ; basal cell closed below except sometimes at extreme 

 base ; row of hairs on lower surface of costal cell always complete . . 4 



