F. R. Petherbridge and M. A. Husain 203 



Yellow dorsal abdominal gland with faintly marked lips. 



Antennae pale orange with a dusky shade in the chitin; terminal 

 joint of same colour, not pink as in P. rugicollis. 



Other characters typical of first Instars. 



Instar II. Length 1-6-1 -8 mm. 



Peculiarities typical of Instar II (see p. 199), otherwise as Instar I. 



Instar III. Length 2- 1-2-3 mm. 



Antennae darker, basal joint darkest. 



Head yellow; thorax and abdomen greyish yellow with a green tinge. 



Eyes dark red with a white margin. 



Peculiarities typical of Instar III (see p. 199), otherwise as Instar II. 



Instar IV. Length 2-6-3-1 mm. 



Peculiarities typical of Instar IV (see p. 199), otherAvise as Instar III. 



Instar V. Length 3-28-3-6 mm. 



Peculiarities typical of Instar V (see p. 199), otherwise as Instar IV. 



Adult. Length 4-5 mm. 



Oval ; o dark brown ; ? varies from grey to dark brown, cuneus always 

 reddish. 



Body covered with long pale hairs which easily rub off. 



No collar on pronotum. 



8. ATRACTOTOMUS MALI (MEY.). 



This species has been accused of doing great damage to the apple in 

 Suffolk and Hereford (26) but in all our experiments we have found it to 

 be quite harmless. It was not found in any great numbers either at 

 Wisbech or at Cambridge, but the trees on which they were found in 

 fair numbers, two or three on one shoot, showed no marks or signs of 

 injury. While one P. rugicollis larva would cover two or three fair sized 

 leaves with brown spots in one night, two even three or four nymphs kept 

 in cages for days on the same shoot did not mark them. W^e regard this 

 species as quite harmless. 



Instar V (PI. X, fig. 11). Small, broad, ovate nymph, with deep dark 

 red colour, very dark on the anterior part of pronotum, wing pads and 

 two basal antennal joints. 



Antennae medium sized with two basal joints very thick and dark red, 

 thickly covered with black hairs. 



The two terminal joints cream coloured with a faint tinge of orange 

 in the terminal joint. 



Femora red, tibiae upper half red, lower half and tarsi pale. 



Proboscis reaches the second coxae. 



Peculiarities typical of Instar V. 



14—2 



