PTEROMALIDAE OF N.W. EUROPE 303 



Gastrancistrus salicis (Nees) 

 (Text-figs. 203, 233, 237, 240, 241) 



Pteromalus Salicis Nees ; 1834 : 105-107, <J $. 



Seladerma Capreae Walker, 1848 : 112 [nee Cynips Capreae Linnaeus, 1761]. 



Tridymus salicis (Nees) Ratzeburg, 1848 : 183,0*$. 



Pteromalus {Seladerma) salicis Walker, 18486 : 218. 



Tridymus salicis (Nees) ; Thomson, 1876a : 196-197,0"$. 



? Tridymus salicis (Nees) ; Felt, 1902 : 744. 



Type material (presumably destroyed). Original specimens reared in April and 

 May from galls on Salix aurita L., near Munich, Germany (" inter Sebersbrunn et 

 Starenberg prope Monacum "), by Alexander Braun of Karlsruhe. The interpreta- 

 tion of Thomson (1876) is followed here, and the name salicis is restricted to the forms 

 which agree with the redescription given below ; the latter is based on a number of 

 accurate measurements taken from the British and other specimens mentioned 

 below, of which those from Sweden are particularly important because they were 

 reared from a host on the plant originally mentioned by Nees, i.e., Salix aurita. 



$. Head and thorax varying from golden or bronze-green through green to greenish blue ; 

 disc of gaster, or the hind margins of its segments, usually tinged with bronze. Mandibles 

 varying from testaceous with darker teeth, to fuscous. Antennae testaceous, usually with their 

 scape infuscate at the tip dorsally, the pedicellus fuscous dorsally over its basal half, and the 

 flagellum more or less infuscate dorsally ; in the darkest forms the scape may be wholly fuscous 

 with a metallic tinge, the pedicellus and the flagellum pale only beneath. Coxae concolorous 

 with the thorax, or with at most their tips pale ; trochanters usually ± infuscate ; femora 

 more or less infuscate proximally with a metallic tinge ; otherwise the legs are usually testaceous 

 with only the fifth tarsal segment brown or fuscous, sometimes the tibiae are more or less 

 infuscate in British specimens. Wings subhyaline ; venation brownish testaceous to fuscous. 

 Tegulae testaceous, their hind edge sometimes darker. Length 2 to 3-1 mm. 



Head in dorsal view (Text-fig. 237) 2-15 to 2-3 times as broad as long ; temples converging 

 fairly strongly behind the eyes ; ocelli in a triangle whose base is 2 to 2-2 times its height, 

 POL 1-5 to 1-7 OOL. Eyes 1-15 to 1-25 times as long as broad, separated by 1-3 to 1-55 times 

 their own length. Malar space half, or slightly more than half, the length of an eye. Breadth 

 of oral fossa 1-9 to 2-5 times the malar space. Clypeus from nearly twice, to slightly more than 

 twice as broad as long, often rather strongly alutaceous but sometimes shiny and almost devoid 

 of sculpture, its anterior margin gently curved. Antennae (Text-fig. 240) with scape about 

 four times as long as broad, its length very slightly less than the transverse diameter of an 

 eye, slightly broader in the middle than at either end ; pedicellus in profile about 1 -6 times 

 as long as broad, as long as or slightly longer than the first funicular segment ; combined 

 length of pedicellus and flagellum slightly less than the breadth of the head ; funicle proximally 

 slightly stouter than the pedicellus in profile, becoming a little thicker distad ; first funicular 

 segment quadrate or slightly longer than broad, the second quadrate to very slightly transverse, 

 the following segments slightly transverse; clava hardly more than twice as long as broad, not 

 quite as long as the three preceding funicular segments together ; sensilla of flagellum fairly 

 numerous, disposed in a single row on each segment. 



Thorax (Text-fig. 202) 1-55 to 1-65 times as long as broad. Mesoscutum 1-5 to 1-7 times 

 as broad as long, moderately shiny, with very fine scaly-reticulate sculpture ; on the front 

 part of the mid lobe this sculpture is slightly raised above the general surface and tends to be 

 transversely strigose-reticulate ; mid lobe with numerous bristles, most of which arise from 

 minute tubercles ; notauli very deep, slightly curved. Axillae with extremely fine alutaceous 

 sculpture. Scutellum distinctly longer than broad, strongly convex, with (5-) 6-12 pairs of 



