A. S. HoRNK AND H. M. Lkfroy 379 



with Aphis. The youngest leaves were chiefly affected and infested, 

 but in this case they were often considerably distorted and their veins 

 discoloured. 



Jassid series. (A) Wisley. 



1. June 5. Three plants were infested with 10, 9 and 9 Jassids respectively, 

 Eupteryx species and a green species. 



June 8. Small white spots were present in the infested plants but absent on 

 the controls (Fig. 9). 



The spots are about 1 mm. in diameter and possess an irregular outline. When 

 a number occvu- close together, whitish blotches or patches are formed, more usually 

 on the upper surface of the leaf. The spots are not confined to the young leaves 

 and do not occui- in sufficient number to cause the death of the leaf directly. The 

 tissue of the leqf is not lacerated as in the case of injuries caused by Capsids. The 

 epidermis is punctured and the proboscis of the insect injures and destroys the 

 chlorenchyma. The white appearance of the spot or blotch is due to the loss of 

 chloi'ophyll and perhaps an optical effect, in part, due to included air. 



2. June 11, 3 p.m. Single plants infested with one Eupteryx collected at 

 Wisley. 



June 12, 10.30 a.m. White spots present on one leaf. Eupteryx still alive. 

 The spots have been produced within 20 hours. 



Jassid series. (B) Chelsea. 



June 9. Put three clean plants under a bell- jar with two winged Eupteryx 

 atropunctata. Controls all clean plants unspotted. 



June 11. Removed the bell-jar and the two bugs; observed small Ught spots 

 on several leaves ; controls not spotted. 



June 13. The spots are slightly brown. 



June 20. The spots are larger and in some cases have become holes. 



Capsid series. (A) Wisley (Fig. 10). 



1. June 12. Put one clean plant under cloche with four wingless green Capsids 

 collected at Wisley. 



June 13. Small brown spots observed on youngest leaves. 



2. June 12. Put one clean plant under cloche with two green winged Capsids 

 collected at Wisley. 



June 13. The following symptoms had developed: 

 black stripe along petiole; 

 dark blotch on leaf lamina; 



young leaves with dark brown irregular blotches on the upper 

 surface. 



3. June 12. Put one clean plant under cloche with two brown winged Capsids 

 collected at Wisley. 



June 13. No visible result. 



4. June 12. Put one clean plant under cloche with three small green and brown 

 grass Capsids. 



June 13. No visible result. 



