14 FIRST REl'ORT OX ECONOMIC BIOLOGY. 



THE MARGUERITE FLY. 



Napomyza later alis, Fall. 



In common with many other species of leaf-mining- flies, this 

 species has been the source of considerable injury to marguerites during 

 the past year. 



FIG. 5. LEAVES OF MARQUERITE, attacked by Fly. 



It is a troublesome pest to control, but spraying the young plants 

 with paraffin emulsion has given excellent results. 



All plants that are badly attacked should be burnt, and others that 

 are less so should be carefully examined, and the diseased leaves picked 

 off and burnt. 



THE FRIT FLY. 



Oscinus jrit, Linn. 



Not for very many years past has this insect been such a serious 

 pest as during 1910; not only was this so in the Midland Counties, 

 but generally throughout the country, and oats and barley have 

 suffered considerably. 



