PTEROMALIDAE OF N.W. EUROPE 657 



Biology. Von Rosen (1962 : 144) stated that nobilis lives in the seeds of grasses 

 and that he had reared it from Avena elatior [=Arrhenatherum elatius (L.) Beauv.] 

 and Bromus inermis [=Zerna inermis (Leyss.) Lindm.]. Later, however (1966 : 82) 

 he suggested that those reared from the latter plant might represent a distinct 

 species. He also (1966 : 82) reared specimens from Avena [=Helictotrichon] 

 pubescens (Huds.) Pilger and A. [=//.] pratensis (L.) Pilger which he thought 

 might be another distinct species ; from his description these specimens evidently 

 belong to the form referred to above as decorus (Walker) . Imagines June-July. 



Mesopolobus prasinus (Walker) 

 (Text-figs. 547-550) 



Platyterma prasinum Walker, 1834 : 305, $. 



Asemantus amphibolus Forster, 1878 : 51, $. 



Platyterma prasinum Walker ; Graham, 1957^ : 221 - 



Mesopolobus prasinus (Walker) v. Rosen, 1958 : 214, <J $• 



Mesopolobus prasinus (Walker); v. Rosen, 1960a : 33-34, 35 [separatum]. 



Mesopolobus prasinus (Walker) ; v. Rosen, 1962 : 145-146. 



Mesopolobus prasinus (Walker) ; v. Rosen, 1966 : 82-83. 



Type material. Platyterma prasinum Walker. Lectotype designated by Graham 



(1957^)- 



Asemantus amphibolus Forster. Type $ (not seen by the writer) in Zoologischen 

 Museum der Humboldt-Universitat, Berlin, according to von Rosen (1962 : 146) 

 who then considered it to be the same as prasinus (Walker). 



In 1957 I noted some differences between the type females of nobilis (Walker) 

 and prasinus (Walker). Von Rosen thought (1960a) that the latter might be a 

 form of nobilis, but later (1962, 1966) decided to leave the question an open one. 

 In 1966 (fig. 2) he illustrated slight differences between the female hypopygia of 

 nobilis and prasinus. 



Since the above papers were published I have examined a series of females captured 

 in southern England within 50 miles of the type locality, which fit the syntypes of 

 prasinus perfectly (incidentally all 5 of the syntypes are very similar and could 

 have been captured together). A study of this material shows that prasinus is 

 without doubt a species distinct from nobilis ; in fact it is usually possible to 

 recognize females of prasinus by their general facies, without detailed examination. 

 The antennae (Text-fig. 547) of prasinus are particularly characteristic. The 

 following redescription has been made from all the above specimens. 



$. Body and coxae varying from bright golden green through green to blue ; legs otherwise 

 yellow to fulvous with the femora usually more or less infuscate proximally, the hind ones 

 often dark with only their bases and tips pale, and the tips of the tarsi darkened. Antennae 

 sometimes fulvous with only the pedicellus more or less infuscate proximally ; sometimes with 

 the scape and the proximal part of the flagellum, slightly infuscate. Wings hyaline ; venation 

 yellowish to testaceous. Tegulae partly to wholly yellow. Length 1-5 to 2-5 mm. 



Head in dorsal view 1-9 to 2 times as broad as long ; temples slightly less than one third as 

 long as the eyes. Malar space half, or very slightly more than half, the length of an eye. Cly- 

 peus strigose or strigose-reticulate. Antennal scape (Text-fig. 547) shorter than an eye. not 



