662 M. W. R. de V. GRAHAM 



In i960 von Rosen recognized clavicornis which he synonymized with laticornis 

 (Walker) ; in 1966, however, he indicated differences between the female hypopygia 

 of laticornis and the species which he determined as clavicornis, consequently he 

 separated them as distinct species. It is unfortunate that a female was not selected 

 as lectotype of clavicornis, because then the hypopygial characters could have 

 been confirmed ; the male is very difficult to separate from that of laticornis. 



According to von Rosen (1966) the female of clavicornis is very similar to that of 

 laticornis but differs in the shape of its hypopygium, also in being smaller (mostly 

 1-5-1-9 mm., seldom 2 mm. or more, in length) and darker. Males are even smaller, 

 and relatively darker. He stated that clavicornis could be distinguished from 

 pseudolaticornis only with the aid of its colour, absolute size, and flight-period. 

 Hypopygium with anterolateral angles prominent ; median sclerotized area narrower 

 and longer than in laticornis, reaching somewhat farther back than the level of the 

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

 less transverse than in laticornis. 



? Britain ; Sweden ; France. 



Biology. Von Rosen (1966) stated that he captured specimens in June and July 

 in Sweden, on panicles of Avena [= Helictotrichon] pubescens (Hud.) Pilger and (less 

 frequently) on those of A. [=H.] pratense (L.) Pilger ; and that he had taken other 

 specimens in August. 



Mesopolobus pseudolaticornis v. Rosen 

 (Text-fig. 553) 

 Mesopolobus pseudolaticornis v. Rosen, 1966 : 78-81, fig. 1, 6* ¥• 



Type material. Holotype $ and allotype,^, Sweden, Skane, Lomma, 13.viii.1963, 

 in Universitetets Zoologiska Institutionen, Lund ; paratypes in Statens Vaxtskydd- 

 sanstalt, Stockholm (not seen by the writer). 



Von Rosen states that the female of pseudolaticornis differs from that of laticornis 

 (Walker) in the shape of its hypopygium, also in being rather more slender, with the 

 mesoscutum more flattened, and in having the femora only slightly darkened. The 

 female of teliformis (Walker) is said to differ from that of pseudolaticornis in having 

 the antennae in general longer and the pronotal collar more sharply margined, but 

 the latter distinction is not evident in smaller specimens. The male of 

 pseudolaticornis, in which the femora are said to be always pale, cannot be 

 distinguished with certainty from those of laticornis and teliformis, according to the 

 same author. His figure of the female hypopygium of pseudolaticornis shows a 

 structure which does not differ greatly from that of clavicornis (Forster) and teliformis 

 (Walker). 



On 13.ix.1962 I captured several specimens of a Mesopolobus which agree with the 

 description of pseudolaticornis, in a marsh at Lodmoor, near Weymouth, Dorset, 

 England. The females of this series have the femora more or less suffused with 

 brown ; in some the fore femora are wholly pale ; one has the mid femora also pale ; 



