26 L. A. MOUND 



BALIOTHRIPS Uzel 



Baliothrips Uzel, 1895 : 204-205. Type-species Thrips dispar Haliday, by monotypy. 

 Euchaetothrips Bagnall, 1916b : 402. Type-species Thrips kroeli Schille, 191 1. Syn. n. 

 Stenchaetothrips Bagnall, 1926c : 107. Type-species Stenchaetothrips melanurus, by monotypy. 

 Syn. n. 



Bagnall indicated that the genus Euchaetothrips, which he erected for kroeli Schille, 

 was ' nearest Thrips (Bagnallia group) '. Bagnallia, as used by Bagnall, is synonym- 

 ous with Baliothrips, Stenchaetothrips was based on two damaged females, and in the 

 opinion of the present author biformis, dispar, kroeli, melanurus and vitipennis 

 should be regarded as congeneric. These five species differ from Thrips species in 

 the arrangement of the postocular setae. If these setae are numbered from the 

 median pair outwards, then pair two is always displaced to the posterior of pairs one, 

 three and four. These postocular setae are well separated from the eye, the cheeks 

 rather long and straight, and the head broadest across the eyes. The fifth antennal 

 segment is broad at the apex and the metanotum is striate. The species may be 

 separated as follows: — 



Key to BALIOTHRIPS Species 



1 Anterior border of pronotum with two pairs of setae, the median pair rather elongate ; 



maxillary palpi three-segmented ....... kroeli Schille 



- Anterior border of pronotum with four or more pairs of setae — if one pair is elongate, 



then these arise just behind the anterior border ; palpi two- or three-segmented . 2 



2 One pair of submarginal setae near anterior border of pronotum rather longer than the 



the other marginal setae .......... 3 



- Setae on anterior border of pronotum of equal length, all arising at the margin ; 



microtrichia of eighth tergal comb simple, each base bears a single apex . . 4 



3 Microtrichia of comb on eighth tergite compound, several apices arise from each base ; 



maxillary palpi two-segmented ; body dark ..... dispar Haliday 



- Comb absent from eighth tergite ; maxillary palpi three-segmented ; body pale, 



abdominal segments IX and X dark ..... melanurus Bagnall 



4 Pronotal disc without setae ....... vittipennis Bagnall 



- Pronotal disc with three or more pairs of setae ; maxillary palpi three-segmented 



biformis Bagnall 



Baliothrips biformis (Bagnall) 



Bagnallia biformis Bagnall, 1913k : 237-238. 

 Bagnallia biformis var. adusta Bagnall, 1913k : 238. 

 Bagnallia biformis var. melanurus Bagnall, 1913k : 238. 

 Thrips biformis (Bagnall) ; Priesner, 1964 : 95. 

 Baliothrips biformis (Bagnall) ; Mound, 1967a : 16. 



The specimen labelled ' biformis v. adusta $ Type ' and one female and three 

 males labelled ' biformis Cotypes ' have been ruined, due to the mountant turning 

 black and the insect body decomposing. The only other material available from the 

 original series is a male and female mounted by C. B. Williams, and it is this female 

 which is here selected as Lectotype. 



LECTOTYPE $. England : Oxford, Weston-on-the-Green, on sedge, i3.viii. 

 1913 (R.S.B.). 



