ANDEIOUS SIEBOLD1I. 87 



Sometimes these galls occur so thickly on a branch as 

 to kill it. The fact of ants feeding on the exudation 

 has been already mentioned (p. 16). 



The inquiline is the root and bark-frequenting 

 Synergus incrassatus, and the parasites Torymus nobilis 

 and Eurytoma rosae. Adler says that the galls of 

 Sieboldii are " in a high degree exposed to the attacks 

 of various parasites of the genera Torymus and Syner- 

 gus" but no names are given. Mayr bred Glinx tri- 

 lineata and Eurytoma rosae from them. 



Sexual Form. — Black, shining ; legs yellow, abdomen for the greater 

 part reddish-yellow, the apical half or so blackish above, the ventral 

 surface paler, hypopygium brownish. Antennae dark brown, the basal 

 three or four joints pale yellow. Hind coxse brownish at the base ; 

 tegulse and a spot (sometimes absent) at the base of the mesonotum 

 brownish-yellow. Scutellum opaque, coarsely aciculate or finely rugu- 

 lose. Face aciculate. Mesonotum more or less at the base pilose. 

 Head elongate, distinctly dilated behind the eyes. 



The (J almost agrees with the $ in colouration ; the third antennal 

 joint is slightly dilated and curved. 



Length 1:5 — 2 mm. 



Agrees with trilineatus in having the head widened 

 behind the eyes, but differs in the black head and 

 thorax. 



Gall. — Forms an elongated swelling on the midrib 

 towards the centre of the leaf, in the petiole, or even 

 on the very young twigs. There is only one cell, but 

 the swelling extends considerably beyond the part 

 where the larva lives ; it is from 1 J to 2 mm. in length, 

 and is surrounded internally by a fine white cellular 

 substance. In colour it is green, differing but slightly 

 from the colour of the leaf. 



Synergus apiealis and Geroptres arator are supposed 

 to be reared from the galls of testaceipes, but they 

 really may have been from those of noduli, the petiole 

 galls of which may have been mistaken for those of 

 testaceipes. The parasite is Megastigmus dorsalis. 



Rare and local in Scotland and England. 



Continental distribution : Switzerland, Germany, 

 Austria. 



