PTEROMALIDAE OF N.W. EUROPE 839 



Type material. Syntypes, 8 $ in Hartig collection, Munich. Seven of these are 

 mounted on card-points which are grouped in a tree-like whorl on one pin, and 

 labelled " 786 ". The eighth specimen (which actually stood first in the series) is 

 mounted, together with an egg of Dendrolimus pini which has an emergence-hole, 

 upon a red-bordered card, and labelled " solitarius " ; this specimen is designated 

 LECTOTYPE. All the syntypes stood next to a Hartig label " Chrysolampus ". 



Hartig originally described the species from material reared from eggs of 

 Gastropacha [= Dendrolimus] pini (L.) (Lep., Lasiocampidae). The name solitarius 

 has sometimes been attributed to Ratzeburg who, however (1844a : 180) expressly 

 quoted Hartig (and incidentally, referred to the host-species as " Kiefernspinner "). 

 Some confusion was caused later by Szelenyi who remarked (1942 : 96) 

 " Pachyneuron concolor Forst. (solitarius Ratz.) lebt nach Ratzeburg einzeln in 

 Eiern von Bupalus piniarius L.". Clearly Szelenyi has here mistaken the 

 " Kiefernspanner " (B. piniarius L., family Selidosemidae) for the " Kiefernspinner " 

 of Ratzeburg (Dendrolimus pini (L.)). 



Pteromalus [= Pachyneuron] concolor Forster has sometimes been considered to be 

 the same as solitarius. Ratzeburg (1848 : 184) mentioned that he had received 

 specimens of concolor from Forster himself, and found them to be the same as 

 solitarius. There is some reason for doubting the correctness of his conclusion, 

 however. Although it is not clear whether he had seen Hartig's types, he presumably 

 had specimens of the true solitarius, since he mentioned (loc. cit.) material reared 

 from the original host by Reissig. Even so, the differences between solitarius and 

 concolor are so small that he was hardly likely to have noticed them. Boucek 

 (19650 : 18) also stated that he considered concolor to be the same as solitarius, 

 which he thought to have a very wide range of hosts. However, Dr. Boucek's 

 own specimens of solitarium, reared from eggs of Dendrolimus pini, differ from 

 concolor Forster (as redescribed by Delucchi) in the shape of the clypeus, a character 

 which appears to be of relatively high taxonomic value in Pachyneuron. Also, the 

 known facts regarding the biology of solitarium and concolor seem to suggest that 

 they are not identical. 



The female of P. solitarium, as interpreted here, is remarkably like that of concolor 

 (Forster). It differs in having the anterior margin of the clypeus (Text-fig. 677) 

 slightly produced, the produced part weakly emarginate or subtruncate, and the 

 surface of the clypeus only weakly convex. In concolor (Text-fig. 678) the anterior 

 margin of the clypeus, which is more strongly convex, has a blunt, rounded median 

 projection. There appear to be other small differences between the two species, 

 in the proportions of the flagellar segments and the gastral petiole, but I have not 

 been able to study a sufficient number of specimens to confirm this. 



Germany, Czechoslovakia, ? Moldavian S.S.R. 



Biology. At present only those specimens reared from eggs of Dendrolimus pini 

 (L.) can be definitely identified as solitarium. In view of the confusion of concolor 

 with solitarium, other records relating to the latter will have to be re-examined. 



