1907.] 



Frit Fly. 



297 



kainit may be applied in early spring and \ cwt. nitrate of 

 soda early in April. 



Gummosis. — Specimens cut from a cherry tree and sent 

 from Bromsgrove were affected with a disease known as 

 gummosis. This disease is caused by a fungus which first 

 attacks the roots and upsets the physiological balance, 

 resulting in the formation of an excess of gum in every part of 

 the plant. No remedy is known for gummosis, but diseased 

 trees should be removed and burnt. It is most important 

 that the root should be completely removed, and the soil 

 sterilised by burning or by the use of gas-lime. Unless this 

 is done the fungus will probably extend in the soil to the roots 

 of adjoining cherry or pi am trees. It would be wise to replace 

 dead or removed trees by apple or pear trees, which are not 

 attacked by this disease. 



The larvae of the Oscinids or Chloropidce — a group of tiny 

 two-winged flies — are known to be very injurious to cereals and 



pasture grasses in Europe and America. 

 The Frit Fly, The species Oscinis frit is one of the chief 



cereal pests in Europe, and there are con- 

 tinental records of Oscinid attacks on oats; barley, wheat, rye, 

 maize, and various grasses. The chief damage in Britain is to 

 oats, although barley may also suffer. The larvae or maggots 

 of the fly do the harm by feeding in the heart of the young 

 plants or in the grain in the young ears, according to the time 

 of the year and the different broods of the insect. 



Every year in England the Frit Fly is the cause of some 

 loss, but there are years that may be spoken of as " frit fly 

 years,' 5 when the infestation and consequent loss is excessive. 

 This year, during June, complaints have been numerous. 

 One correspondent, sending a sample, writes of his oats rotting 

 and withering away. Another writes of taking out " hand- 

 fulls of infested plants." Still another writes, " I have a 

 field of oats this season quite useless ti as aVcrop. The oat 

 plants have continuously weakened r " t and many have died 

 during the past five or six weeks." A typical communication 

 from Oxfordshire tells how " some oats planted in April 



