PTEROMALIDAE OF N.W. EUROPE 841 



frontalis Alam and T. marsus Walker), and a Dipteron, Leucopis silesiaca Egger 

 (Chamaemyiidae) , were also reared. A number of the Eriopeltis ovisacs were 

 isolated and their contents investigated. From a study of this material Professor 

 Varley (1966) concludes that the Pachyneuron is a hyperparasite of the Eriopeltis 

 through the species of Trichomasthns. None of the Leucopis had been attacked by 

 the Pachyneuron ; this is interesting because certain other species of this genus 

 (cremifaniae Delucchi and vitodurense Del., q.v.) have been recorded as parasites of 

 Chamaemyiidae. Evidently more research is needed on the precise relationships 

 between various species of Pachyneuron and their hosts. Imagines of concolor are 

 most frequent in the field from July until September in Britain, though some may be 

 found earlier. 



Considerable variation exists in the reared series of concolor, and it may be useful 

 to record this here. The females vary in length from 1 -3 to 2 mm. ; the head and 

 thorax are most often bluish black or dark blue, but the colour ranges from dark 

 blue-green to violet-black, the propodeum tending more towards greenish ; usually 

 only the femora, especially the hind ones, are more or less infuscate, but sometimes 

 the tibiae are also more or less infuscate, mainly so in some specimens from northern 

 Britain ; the first segment of the antennal funicle varies from slightly transverse to 

 very slightly longer than broad (in large specimens), and this segment is usually 

 slightly shorter than the second segment, hardly two thirds as long as the second in 

 very small specimens, occasionally as long as the second in large ones ; segments 

 2-5 are usually a little longer than broad (up to 1-5 times) though sometimes 

 quadrate ; segment 6 is usually quadrate, occasionally very slightly transverse in 

 small specimens, very slightly longer than broad in large ones ; the sensilla are 

 relatively sparse, very sparse in small specimens ; the propodeum, above the 

 supracoxal flange and mesad of the spiracular sulcus, has 1-3 hairs on each side ; 

 the basal vein of the fore wing is pilose throughout, whilst the speculum is normally 

 closed below, occasionally partly open. Males vary from 0-9 to i-y mm. in length ; 

 the head and thorax vary from a fairly bright green, to dark blue, in the latter case 

 the front of the head tends to remain green ; the femora are sometimes pale, some- 

 times (especially the hind ones) more or less infuscate ; the tibiae occasionally have a 

 fuscous antemedial band ; the first funicular segment varies from quadrate (small 

 males) to 1 -8 times as long as broad, this segment being sometimes as long as the 

 second though usually slightly shorter ; the middle segments of the funicle vary 

 from 1-5 to 2 times as long as broad ; the sixth is usually a little shorter than 

 segments 2-5. 



Pachyneuron vitodurense Delucchi 



Pachyneuron ferrierei Delucchi, 1953 : 2-8, £ $ [nee Mani, 1939]. 



Pachyneuron ferrierei Delucchi, 1954 : 246. 



Pachyneuron vitodurense Delucchi, 1955b : 137, $ [n. n. for ferrierei Delucchi nee Mani]. 



Type material (not seen). Delucchi (1953) stated that the type [data not 

 specified] of ferrierei had been placed in the European Laboratory of the Common- 

 wealth Institute of Biological Control, with 4 paratypes in the Institut Royal des 



