120 M. W. R. de V. GRAHAM 



Platygerrhus dolosus (Walker) 



Trigonoderus dolosus Walker, 1836a : 23, $ (nec^). 

 Trigonoderus hirticomis Walker, 1836a : 23, <$, syn. n. 

 Platygerrhus dolosus (Walker) Kerrich & Graham, 1957 : 3°3> 6* ?• 

 Platygerrhus dolosus (Walker) ; Ferriere & Kerrich, 1958 : 30. 



Type material. Trigonoderus dolosus Walker. Lectotype 9 designated by 

 Kerrich & Graham (1957 : 303). 



Trigonoderus hirticomis Walker. Two specimens stand under this name. One 

 is labelled " hirticomis? Moncreaff " and cannot be a syntype ; it is a^ Eupelmella 

 vesicularis. The other, bearing a Waterhouse label " Trigonoderus hirticomis ", is 

 represented by the wings and one mid tarsus only ; these remains indicate that it 

 was also a $ Eupelmella. I have not seen any $ of the latter which would fit the 

 description of hirticomis. On the other hand the description fits some small males 

 of Platygerrhus dolosus extremely well, so that I feel justified in synonymizing 

 hirticomis with dolosus. Walker (1836a : 23) described what he supposed to be the 

 <$ of his dolosus but his identification was wrong since the J syntype of dolosus (the 

 only $ standing under that name) does not belong to that species, but possibly to 

 longigena sp. n. 



Trigonoderus lappa Walker, 1848, placed in synonymy with dolosus by Kerrich & 

 Graham (1957 : 303) does not belong to that species, but probably to ductilis (see 

 below) . 



Britain, Sweden, Czechoslovakia. 



Biology. Reared in England as an external parasite of Laemophloeus ater (Oliv.) 

 (Col., Cucujidae), a predator of Phloephthorus rhododactylus (Marsh.) (Col., Scolytidae) 

 on broom, Sarothamnus scoparius (L.) Wimmer (M. R. Smith) ; see Ferriere & 

 Kerrich, 1958 : 30. Imagines Apr-May and Aug.-Sept. 



Note. Whilst this paper was in proof, Hedqvist (1968, Ent. Tidskr. 89 : 38) 

 described a new species Platygerrhus americanus, which he compared particularly 

 with dolosus. I have seen a paratype $ of americanus, which differs from $ longigena 

 in having the costal cell of the fore wing very narrow (length : breadth about 

 15 : 1), its upper surface virtually bare, lower surface (and the rest of the wing) 

 more sparsely pilose ; base of costal and basal cells broadly infuscate ; middle of 

 propodeum wholly violet. 



Platygerrhus longigena sp. n. 



(Text-figs. 82, 86) 



o*. Head and dorsum of thorax deep bluish green, the scutellum mainly bronze, mesoscutum 

 and axillae partly tinged with the same colour; sides of thorax with weaker greenish and bronze 

 reflections ; propodeum including the spiracular regions bluish or greenish, except the calli 

 which are bronze or purplish bronze ; gaster black with a weak violet tinge, the basal tergite 

 partly blue-green. Mandibles reddish. Antennae black ; scape slightly metallic. Coxae 

 concolorous with sides of thorax ; trochanters partly fuscous, partly testaceous ; femora black- 

 ish with a metallic gloss, except their tips very narrowly, and a stripe on the mid femur, which 



