354 



Insect, Fungus and other Pests. 



[SEPT., 



mushrooms from Highgate, which were infested with a 

 dipterous maggot, not, however, the ordinary fungus-gnat 

 maggot (see Journal, June, 1907, page 162) . The fly will be bred 

 out, if possible, for accurate determination. Some species of the 

 family Mycetophilidce or fungus-gnats are, on occasion, very 

 harmful to mushrooms, while other and related species are 

 destructive to injurious fungi, or are scavengers. Where 

 flies are found to be numerous in a mushroom house the house 

 should be fumigated. The flies often congregate on the glass 

 of small windows in such houses, and spraying with paraffin 

 will kill these and so prevent egg-laying. 



Among other flies, the Carrot Fly, Psila rosce (see Leaflet 

 No. 38) was sent from Braintree ; and the Cabbage Root Fly, 

 Phorbia brassiccz (see Leaflet No. 122) from Earls Barton, 

 Northampton. 



Aphides. — Specimens of various kinds have been received 

 infested with aphides : Rose and plum from Auchterless ; 

 peach, cherry and plum from Farnborough ; cherry from 

 Claygate, Surrey ; Woolly Aphis on apple from Hayle, Corn- 

 wall ; and Larch Aphis from Whixley, Yorks., and several 

 other localities. Aphides are described in Leaflets No. 34 

 (Woolly Aphis), No. 88 (Hop Aphis), No. 68 (Currant Aphides), 

 No. 104 (Aphides or Plant Lice). 



In connection with the specimens of Cherry Aphis from 

 Farnborough, it may be said that as this aphis produces much 

 honey-dew, quassia should be used in conjunction with soft 

 soap, though not if the fruit is maturing. The correspondent 

 mentioned the fact that some of the branches of the cherry 

 trees were overweighted with leaves. This may possibly be 

 due to an excessive application of manure early in the season. 

 It is recommended by a grower who has made a practical study 

 of the subject that liquid manure should be applied while the 

 fruit is swelling, viz., § lb. sulphate of ammonia and \ lb. 

 sulphate of potash to 40 gallons of water. 



Aphis on Ash. — From Basingstoke the Board received a 

 specimen of ash infested with an aphis which, judging from 

 the appearance of the specimen and from the ball or nest-like 

 formation of the leaves attacked, was probably Pemphigus 

 nidificus, Low. There appears to be only one mention of this 

 aphis in the literature on the subject, and this refers to Germany. 



