678 



Currant Bud Mite and Hazel Bud Mite, [feb., 



I give below, placed in parallel columns for the sake of 

 reference, a translation from Nalepa's work on Eriophyidce 

 of the distinguishing characters of the two species : — 



Hazel Bud Mite. 

 {Eriophyes avellance. ) 



The dorsal shield (on the front region 

 of the body, known as the cephalo-thorax) 

 triangular, rounded in front, and traversed 

 by a not very prominent longitudinal line. 



The shield has short dorsal bristles 

 directed outwards, inserted in front of 

 the hinder edge, and a second shorter pair 

 at the side. 



Joints 4 and 5 of the legs approximately 

 equal in length. 



The bristles on the small process at the 

 end of the leg are four-plumed or four- 

 rayed. 



The sternum (the region on the under 

 surface, where the epimera or plates that 

 fix the legs to the thorax meet) not forked. 



Setae Laterales short and fragile (these 

 are the first pair of bristles borne by the 

 abdomen ; they are situated one on each 

 side, on the under surface, about level 

 with the sexual apparatus). 



Setae Ventrales I short ; the same length 

 as the setae laterales (setae ventrales I = 

 the pair of bristles some distance behind 

 the setae laterales, and springing not from 

 the edge but from the under surface of the 

 abdomen. 



Setae ventrales II (the next pair of 

 bristles) very short. 



, Setae ventrales III somewhat longer 

 .than setae ventrales I (they are almost at 

 the hind end and spring from the under 

 surface). 



•. Tail bristles short. 



The abdomen has on its upper surface 

 behind the shield a pair of bristles. 



Epigynium (the ventral plate, situated 

 on the under surface of the abdomen 

 behind the legs), half globular and smooth. 



Male measures 1 80 micros long, 40 micros 

 broad ; female measures 210 micros long, 

 50 micros broad. A micro = -grtnjo inch. 



Black Currant Bud Mite. 

 {Eriophyes ribis. ) 

 The dorsal shield is almost triangular ; 

 its middle region has five longitudinal 

 lines, and the side portions are coarsely 

 punctured and traversed by wavy lines. 

 The shield has no dorsal bristles. 



Joints 4 and 5 of the legs about equal 

 in length. 



The bristles on the small process at the 

 end of the leg are five-plumed or rayed. 



The sternum forked. 



Setae ventrales I long ; much larger 

 than the setae laterales. 



Setae ventrales II short. 



Setae ventrales III short, but rather 

 longer than setae ventrales II. 



Tail bristles very long. 

 No such bristles. 



The ventral plate is grooved. 



Male measures 150 micros long, 38 

 micros broad ; female measures 230 micros 

 long, 40 micros broad. 



Summarising our present knowledge of the genus Eriophyes 

 we may say : — 



1. That the species of the genus Eriophyes to a great extent 

 confine themselves each to one food plant. 



