8i2 M. W. R. de V. GRAHAM 



longer than the stigmal vein, rarely very slightly shorter ; the stigma (Text-fig. 294) tends to 

 be smaller than in boarmiae and as a rule not subrectangular. 



^. Head and thorax greenish to bluish, the axillae and scutellum concolorous, or the 

 scutellum at most slightly tinged with bronze ; gaster nearly always without, or with a very 

 small and indistinct pale spot, rarely with the spot distinct. Antennae variable in colour, often 

 entirely testaceous but sometimes having the pedicellus and scape infuscate, occasionally with 

 the flagellum brownish. Legs sometimes as pale as in boarmiae, but in dark forms having both 

 the femora and tibiae heavily infuscate. Antenna (Text-figs. 664, 665) with scape slender, 

 6-5-7-5 times as long as broad, without a projecting lobe at its distal end ; pedicellus shorter 

 than in the female, hardly more than twice as long as broad ; funicle slender, its segments 

 quadrate, or the proximally ones slightly longer than broad ; clava 2-3-3 times as long as 

 broad ; flagellum clothed with hairs most of which are curved, subdecumbent, and longer 

 than those of fuscicornis . 



Europe (probably whole) ; Canada, U.S.A. It has also been reported from 

 China, Korea, North Africa, and Uruguay, but these records need confirmation. 



Biology. If all the host-records in the huge list of Peck (1963 : 682) are correct, 

 then cavus is a very polyphagous species. They include many records of cavus as 

 a secondary parasite in the cocoons of Ichneumonidae and Braconidae which 

 attack lepidopterous, and sometimes coleopterous, hosts ; but sometimes cavus acts 

 as a primary parasite of the larvae. Sometimes it has been reared from the puparia 

 of Tachinidae which are parasites on insects of other orders. It has even been 

 recorded as parasitizing other Chalcidoidea, or even other individuals of its own 

 species. Balduf (1937 : 181) remarked " Perhaps no other species of parasitic 

 Hymenoptera is reported more frequently in the literature than this small chalcid ". 

 In Britain imagines have been captured in the field May-Sept, (one record for 

 November) . 



Dibrachys (Dibrachys) boarmiae (Walker) comb. n. 

 (Text-figs. 669, 671) 



Pteromalus Mesoleptorum (Kollar MS.), Walker, 1847 : 230 [nom. nud.]. 

 Pteromalus Boarmiae Walker in Newman, 1863 : 8609, [8610], $. 



Type material. Pteromalus boarmiae Walker. Syntypes, 3 $ mounted on the 

 same card and bearing a label " boarmiae " in Walker's handwriting ; the third 

 (right-hand) specimen is designated LECTOTYPE. Walker's description of 

 boarmiae is rather confused. On page 8609 of his 1863 paper he gave a Latin 

 diagnosis of Pteromalus boarmiae, followed by an English description. On page 

 8610 he gave a latin diagnosis of Tetrastichus decisus, likewise followed by an English 

 description. The respective English descriptions have clearly been accidentally 

 transposed ; that on page 8610 really applies to Pteromalus boarmiae and not to 

 Tetrastichus decisus, that on page 8609 applies to T. decisus, as a comparison with 

 the respective Latin diagnoses shows. 



The differences between boarmiae and cavus are very small but I think that the 



