o M. W. R. de V. GRAHAM 



i (2) Combined length of pedicellus and flagellum 1 -5 to 1 -65 times the breadth of the 

 head. Dorsellum with 3 to 12 hairs. Malar space from barely two fifths, to 

 slightly less than half, the length of an eye. Fore wing with parastigma 

 usually as long as or longer (rarely slightly shorter) than the marginal vein. 

 Gaster 3-2 to 4-5 times as long as broad, 1 -2 to 1 -4 times as long as head plus 

 thorax. Vertex nearly always bright to dark blue princeps Westwood (p. 100) 

 Combined length of pedicellus and flagellum 1-3 to 1-35 times the breadth of 

 the head. Dorsellum bare. Malar space approximately half the length of 

 an eye. Fore wing with parastigma usually slightly shorter than, occasion- 

 ally as long as, the marginal vein. Gaster 2-3 to 3-2 times as long as broad, 

 not more than 1-2 times as long as head plus thorax. Vertex usually 

 greenish ........ pulcher Walker (p. 101) 



(Males) 



Antennal flagellum having all its segments distinctly separated, not differen- 

 tiated into funicle and clava . . . cyanescens (Forster) (p. 102) 

 Antennal flagellum with six funicular segments and a three-segmented clava 2 

 (1) Postmarginal vein of fore wing strongly curved and almost reaching the tip of 



the wing ........ filatus Walker (p. 101) 



Postmarginal vein less strongly curved and not nearly reaching the tip of the 



wing ........ princeps Westwood (p. 100) 



pulcher Walker (p. 101) 



It is not possible at present to distinguish the males of princeps and pulcher. 



Trigonoderus princeps Westwood 



Trigonoderus princeps Westwood, 1832a : 127. 



Pteromalus invenustus var. /? Walker, 1836a : 11, 6*. 



Trigonoderus obscurus Walker, 1836a : 21, $. 



Trigonoderus atrovirens Walker, 1836a : 22, $. 



Pteromalus hirtipes Zetterstedt, 1838 : 422, "o*? " [recte $]. 



Trigonoderus obscurus Walker ; Haliday, 1 841-1842 : v, pi. E, fig. 1, 9. 



Pteromalus Lichtensteinii Ratzeburg, 1844a : 188, §. 



Trigonoderus princeps Westwood ; Kerrich & Graham, 1957 : 287. 



Type material. For a full discussion of the synonymy, and designation of lecto- 

 types, see Kerrich & Graham (1957 : 287-292). In that paper Trigonoderus 

 pulcher Walker, T. tristis Walker, and T. contemptus Walker were all placed in 

 synonymy with princeps Westwood ; I now regard pulcher as a valid species, with 

 tristis and contemptus as synonyms (see below). 



Britain, Sweden, Germany, Czechoslovakia, PMoldavian S.S.R. 



Biology. Reared in Sweden from Scolytus ratzeburgi Jans., by A. Jansson (see 

 Kerrich & Graham, 1957 : 292). The record of its having been reared in the 

 U. S.S.R. (W. Caucasus, Sotchi) from Parmena balteus L. (Col., Lamiidae) by S. 

 Novitzky (Kerrich & Graham, ibid.) needs confirmation ; the specimen there referred 

 to might in my opinion prove to be distinct from princeps. Imagines May- 

 September. 



