1884.] INSECT PBEVENTION. 417 



INSECT PBEVENTION. 



II. 



NOTHER crop attacker which entirely depends (as far as crops 

 are concerned) for its winter home on finding a shelter v)ithin 

 the stems of corn stubble, is the corn saw-fly, the ceijlius inj(jmmis. 

 This is a small black and yellow four-winged fly, very like a thin-bodied, 

 light-made wasp in shape, and it is to be found in great numbers in 

 flowers in summer. The white maggot feeds within corn stallvs, and 

 having eaten its way upwards through the knots, travels down again 

 to the lowest part of the stem, and there spins itself a case in which it 

 passes the winter ; and here, in spring or early summer, it turns to a 

 pupa, from which the saw-fly comes out in time to set on foot a new 

 attack on the growing crop. This is not a commonly injurious insect 

 in this country, although sometimes very destructive on the Con- 

 tinent ; but I have found the maggot in stubble in West Gloucester- 

 shire, and any treatment by which stubble can be collected and burnt 

 will easily get rid of the threatened attack from within it. Burning 

 the refuse straw of the gathered crop is also an excellent way of 

 much lessening the amount of the destructive mustard-beetle of the 

 Fen country. This beetle, like the turnip flea-beetle, hibernates, and 

 spends the winter in any convenient shelter, from which it comes out 

 to carry on its life work in the spring ; and it is stated it will bear 

 the most severe weather sheltered in the pipes of reeds near drains 

 and ditches, and the beetles also secure themselves in the old mus- 

 tard stems. Consequently, it would do great good to destroy this 

 refuse, instead of saving it for rough roofing or other purposes ; and 

 getting rid of reeds, rushes, and rough grass, in the roots of which 

 the mustard-beetles shelter, would also be highly desirable. These 

 attacks are just mentioned to show that there are cases in which 

 merely destroying rubbish, or what is of little value as manure, will 

 act at once in lessening the amount of insect presence; but the 

 point of crop pests sheltering for the winter amongst grass or 

 corn roots brings us on to an attack of great importance generally, 

 and of much interest here. I allude to that of the wheat midge. 

 We know that this very small, yellow, gnat-like fly lays its eggs 

 in corn ears when they are coming into blossom ; and though 

 these midge gnats are so small that they may be easUy overlooked, 

 excepting when they are out in numbers in the evening, yet the 

 yellow or scarlet legless maggot which hatches from them may be 

 fairly seen in the injured ears, and if we look at some of the 

 peculiarities of the attack, which have not yet been much 



