280 



all the bugs have hatched and spraying may continue for some time 

 after the fruit has become marked. A high pressure pump and a 

 fairly coarse nozzle should be used. The trees should be thoroughly 

 drenched in a downward direction. As eggs are laid in the_ young 

 shoots, trees from an infested nursery should not be planted in non- 

 infested areas. 



Orthotylus marginalis, Kent, [nassatus, Fall.) hatches about a fort- 

 night later than P. rugicoUis ;. this species is not of any importance 

 as"a pest. Psallus amhigmis, Fall, {obscurus, D. & S.) hatches about 

 the same time as P. rugicoUis, and apparently does no damage. It 

 was observed that the larvae of this species lived and developed for 

 weeks on dried shoots without any leaves, indicating some other 

 source of food than plant juices. On these twigs were eggs and 

 nymphs of the apple-sucker {Psylla mali) and eggs and young of red 

 spider {Tetranychus sp.), and it seems likely that besides sucking 

 plant juices to a certain extent Psallus ambiguus may be carnivorous 

 and therefore beneficial. Atractotomus yiiali, Mey., has not been 

 observed to do any damage to apples. 



No insect enemies of Capsids have been observed. AntJiocoris 

 sylvestris was found sucking the dead bodies of Capsids at various 

 stages, and it is possible that this bug as well as some species of 

 Capsids are capable of killing living Capsids, though they have never 

 been observed to do so. 



Imms (A. D.). Observations on Pimpla pomorum, Ratz., a Parasite of 

 the Apple Blossom Weevil. — Ann. App. Biol, Cambridge Univ. 

 Press, iv, no. 4, March 1918, pp. 211-227, 1 plate, 1 fig. 



Anilionomus poinorum (apple blossom weevil) is a very difficult pest 

 to control owing to its being concealed within the unopened blossom 

 buds of the apple during the early stages. The larvae are frequently 

 found in one of the deformed buds, accompanied by the smaller larva 

 of Pimpla pomorum, Katz., which is an ecto-parasite of both larvae 

 and pupae of the weevil. When the larva of P. pojnorum is fully 

 fed, it spins a slight silken cocoon within the bud-cavity, the adults 

 beginning to emerge about the 17th June or some 23 days after pupa- 

 tion began. The male parasite was found in considerable numbers 

 for the first time and w^as identified. After emergence in June the 

 life-history of P. pomorum during the rest of the year is unknown. 

 Most probably it passes through a second generation and utilises 

 certain species of Lepidoptera as hosts. In localities where A. 2)omorum 

 does not occur both generations probably parasitise Lepidoptera. 

 Among 1,270 apple buds from Cambridgeshire infested with A. pomorum 

 27 per cent, were found to be eft'ectively parasitised by P. pomorum. 



An account is given of Decaux's method of preserving Braconid 

 parasites of A. pomoru7n in France in 1880. About ]3|- bushels of 

 infested buds were collected from 800 apple trees ; these were pre- 

 served in boxes covered with gauze, which was raised from time to 

 time to allow of the escape of the parasites. By this means some 

 250,000 parasites were Hberated, and repetition of the operation in 

 the following year was sufficient to prevent serious damage from 

 the weevil during the succeeding ten years. It is suggested that 



