110 Caj)sid BiKjs and Ajyples 



species are {l)Lygus jyratensis Fab., (2) Psallus ambiguus Fall., (3) Atracto- 

 tomus mail Mey., (4) Plesiocoris rugicollis Fall., (5) Orthotylus marginalis 

 Reut. The first of these, L. pratensis, may be dismissed at once from 

 the enquiry since only one or two specimens in all were fomid in the 

 affected orchards. Its mode of injury too, as described by Collinge and 

 Taylor, differs from that actually observed, and consists in a dimpling 

 of the fruit. L. pratensis is a species which hibernates as an adult, 

 and lays eggs in the early spring ; occasionally these eggs are laid under 

 the cuticle of the young apple, and as the fruit grows a dimple is formed, 

 which persists until the fruit is mature. In the case of this species, 

 therefore, the injury is not always the result of the punctures made 

 by the bug in feeding. 



As regards the other species just mentioned, their distribution in 

 the affected orchards may be seen from the accompanying table. In 

 the same table a few selected unattacked orchards are given to show 

 which species may be present in an orchard without producing injury. 



1. Suffolk affected 



2. Worcester affected 



3. Worcester affected 



4. Worcester unaffected 



5. Nottingham affected . . 



6. Hertford unaffected . . 



7. Cambridge unaffected 



Note. In No. 3 0. marginalis was scarce. In No. 4 two specimens only of 0. mar- 

 ginalis were obtained. In the other cases the " X " implies that the species was exceed- 

 ingly abundant, the " O " that it was absent 



Taking these species singly it will be seen that P. ambiguus was 

 found abundantly in all orchards and can hardly be the cause of the 

 damage. It is a small brown or red species which is usually very common 

 on apples everywhere. 



The second species, A. mali, was considered by Theobald to be 

 responsible for injury in Kent ; in the present case it was absent from 

 two affected orchards, present in the other two, but also present and in 

 large numbers in an unaffected orchard. It is not therefore considered 

 here to be a markedly injurious species. In colour and shape it somewhat 

 resembles P. ambiguus, but may at once be known by its small size 

 and thickened antennae. The third and fourth species, P. rugicollis and 

 0. marginalis, may be considered together. Both species were present 

 in two of the affected orchards and in each of the other cases of attack 



