PTEROMALIDAE OF N.W. EUROPE 661 



Mesopolobus laticornis (Walker) 

 (Text-fig. 552) 



Platyterma laticovne Walker, 1834 : 304, $. 

 Platyterma laticovne Walker ; Graham, 19570' : 221-222. 

 Mesopolobus laticornis (Walker) v. Rosen, 1958 : 215, $. 

 Mesopolobus laticornis (Walker) ; v. Rosen, i960 : 16-22, [ex parte]. 

 Mesopolobus laticornis (Walker) ; v. Rosen, 1960a : 29, [ex parte]. 

 Mesopolobus laticornis (Walker) ; v. Rosen, 1962 : 142-144. 

 Mesopolobus laticornis (Walker) ; v. Rosen, 1966 : 78, fig. 1, o* $• 



Type material. Lectotype designated by Graham (1957^). 



In my paper of 1957a 1 I suggested that laticornis might be only a colour form of 

 teliformis, although I provisionally kept the two separate. Von Rosen at first 

 (1958) followed this view, later (i960) united them ; still later (1962) he found 

 differences between the hypopygia of their respective females and once more 

 regarded them as distinct species. These oscillations of opinion reflect the diffi- 

 culties inherent in a study of this species-complex. My latest research confirms 

 von Rosen's view that teliformis and laticornis are distinct. 



$. Differs from that of teliformis in its darker femora, on the average shorter gaster, and 

 hypopygium ; from clavicornis (Forster) in the shape of its hypopygium ; and from that of 

 pseudolaticornis in its hypopygium, and in having the femora on the average more extensively 

 infuscate. Head and thorax often more obscurely metallic than in teliformis , tending towards 

 bronze-green in some specimens ; fore and mid femora infuscate at least basally, hind femora 

 with at least their basal half fuscous to black with a metallic tinge, often wholly so except their 

 tips. Length i-6 to 2-7 mm. Gaster 2-4 to 3 times as long as broad, i-i to 1-3 times as long as 

 head plus thorax. Hypopygium (Text-fig. 552) with anterolateral angles not very prominent ; 

 median sclerotized area broad and short, reaching at most slightly farther back than the level 

 of the hind edges of the sublateral sclerotized areas ; the whole hypopygium appearing rather 

 strongly transverse. 



o*. Femora more or less infuscate, at least the hind femora dark at base ; but most often 

 the fore and mid femora have at least a dark spot at the base beneath. Malar space 0-47 to 0-5 

 length of eye. 



Britain, Ireland, Sweden. 



Biology. Von Rosen (1966 : 78) recorded having reared laticornis in Sweden 

 from Avena elatior [= Arrhenatherum elatius (L.) Presl.] ; in Britain imagines 

 appear from mid- June until early September. 



Mesopolobus clavicornis (Forster) 



Syntomocera clavicornis Forster, 1878 : 53, o* ?• 



Mesopolobus laticornis (Walker) v. Rosen, 1960a : 29, [ex parte]. 



Mesopolobus clavicornis (Forster) v. Rosen, 1966 : 81-82, o* $• 



Type material. Lectotype <$ (in Zoologisches Museum der Humboldt-Universitat, 

 Berlin) selected by Novitzky and validated by von Rosen (1960a : 29). It is labelled 

 " 17/291, 30/6 Montjoie, Frst, Syntomocera clavicornis Forst. <$ $ Typi Det. S. 

 Novickij ". There are two female paratypes in the same collection. 



