182 A Stadu of Hit Capsld Bwjs found on A^yple Trees 



eggs by means of a surface examination even after cleaning the twigs 

 with dilute potash, but were able to find them by peeling the bark 

 when the eggs remained sticking to it. We kept a number of these twigs 

 in water in the laboratory in the hope that young larvae would hatch out 

 from some of the eggs. Fortunately we were rewarded by getting a number 

 of young P. rugicollis larvae (one of which we observed emerging from an 

 egg) from shoots brought in at the end of April. 



These started to hatch on May 5th. Up to this date no capsid larvae 

 had hatched at Wisbech, but a visit on May 7th revealed the presence of 

 many newly hatched larvae. The young leaves of the shoots on which 

 they were found were marked with brown spots. 



As we were unable to identify the young capsids until later on 

 we classified them under the headings A, B, C, etc. The larvae and 

 nymphs were taken to the laboratory, carefully examined, classified and 

 some of them measured and drawn. Some were preserved, others placed 

 singly on shoots in cages, and others put into sleeves on apple trees, each 

 sleeve containing a single bug. Young bugs were brought in three or four 

 times a week and the development in the laboratory checked by the 

 stages found at Wisbech. All the different stages found were placed on 

 shoots in cages and sleeves and their behaviour noted. We were thus able 

 to find out which of the species did damage and at what stages the 

 damage was done to the leaves, fruit and young stems. Precedence was 

 given to P. rugicollis in our observations as this was soon found to be 

 the only culprit. Altogether we had over fifty cages of P. rugicollis and 

 about an equal number of the other bugs. We sleeved about fifty P. 

 rugicollis, and a large number of the other bugs each in a separate sleeve. 

 We sleeved some P. rugicollis singly on black currants and plums, and 

 also took some larvae and nymphs of P. rugicollis which were damaging 

 black currants at Histon and sleeved them at different stages on apples. 



The sleeves gave very good results and there were very few casualties. 

 We were successful in rearing them in cages, but there were more deaths 

 on account of their drowning or falling -down at night. At first we 

 put the twigs in beakers of water with a bug on each twig, but they often 

 crawled down the twigs and got drowned. We then kept the twgs in 

 small flasks of water, plugging the mouth of the flask with cotton wool 

 and placed it in a large beaker covered at the top with a piece of 

 muslin. These cages proved fairly successful, the chief drawback being 

 that the bugs often fell down into the beaker and had to be replaced 

 two or three times a day. The shoots were changed every two or three 

 days in order to keep conditions as normal as possible. In spite of the 



