5-4 Proceedings, 1922 



1. Second to eiglitli abdominal segments (at least in the male) armed at 

 the side with a posteriorly directed tooth. Tube 5-7 times as long as 

 the 9th segment. 

 2. Head about twice as long as broad. 1st antennal joint armed with 



a strong bristle Actinothrips Bagnall 



2. Head not quite three times as- long as broad. 1st antennal joint 

 without a thorn. 

 3. Bristles on the head normally developed, not very long. 



Idolothrips Haliday 



3. A short, thick sidewise-directed tliorn on each side of the anterior 

 ocellus. Postocular bristles and a pair between them and the 

 posterior margin clearly developed, much longer than the width 

 of the head. Anactinothrips Bagnall 



MEGATHRIPIDAE 



1. Fore ocellus further distant from the two side ones than these are 

 from one another Subfamily Bactrothripinae 



1. Fore ocellus not further distant from the two side ones than these are 

 from one another Subfamily Megathripinae 



BACTROTHRIPINAE 



1. Fifth abdominal segment (in tlie male) with a pair of posteriorly 

 directed stunted processes on the side ; the sixth segment with a shorter 

 straight pair near the last third of the segment; posterior angles of 



the ninth segment forming thorned humps Eidothrips Bagnall 



1. Fifth abdominal segment in the male without horned pi-ocesses. 



2. Horned process of the sixth male abdominal segment long, reach- 

 ing to about the posterior margin of the 7th segment, scarcely 

 diverging towards the back. The 7th and 8th segments on each 



side with a clear tooth-like process .....Bactridothrips Karny 



2. Horned process of the 6th male abdominal segment shorter and less 

 markedly diverging, hardly reaching to the middle of the 7th seg- 

 ment, the latter on each side with a short tooth-like process. Tlie 

 8th segment marked with irregular knobby markings. 

 3. Horned process of the 6th male abdominal segment somewhat 



shorter, still diverging at the end Bactrothrips Karny 



3. Horned process of the 6th male abdomin.il segment longer 

 slightly diverging at the distal end Krinothrips Bagnall 



MEGATHRIPINAE 



1. Horned process of the 6tli male alnlominal segment as a rule extending 

 past the end of the 7th segment, bent outwardly. 



