150 Insect Pests. 



Failures in treatment are all because we ignore the presence of 

 the migrating ground form, which we so often know occurs where 

 the aerial form does, just as happens with the Vine Phylloxera 

 { Phylloxera devasta trix). 



That the Currant Eoot Louse (Scliizoneura fodicns) attacks the 

 apple there is no doubt, but this is only where currants, etc., are 

 grown under apple trees (2). That this is exceptional, and that it- 

 is the "Woolly Aphis that causes the main loss to apple is, however, 

 now an established fact, and is becoming well known amongst all 

 up-to-date growers. 



Thus we have this apple pest living during the winter in three 

 ways : (1) above ground as adults, in crevices of the bark, etc. ; (2) 

 in the egg stage ; and (3) as a root form below ground. 



In summer we get it in two conditions only : (1) As active adults 

 forming an aerial race, and (2) as active adults forming a subterranean 



NATURAL ENEMIES. 



These are very few and of no economic importance, except in the 

 case of birds. Of these the Blue Tit (Pants cceruleus) is undoubtedly 

 the most important. This useful little bird, which every fruit-grower 

 should encourage, hunts all through the winter for this pest, and 

 does much to lessen its numbers as it does for many other 

 orchard enemies. The Great Tit (Parus major), the Tree Creeper 

 (Certhia familiaris), and even Sparrows prey upon it during the cold 

 months. 



Xo insect enemies are of any great value as natural checks. 

 Some Coccinellid larvae feed on them, and on some occasions I 

 have seen Coccinella septem-punctata clear away colonies of this 

 insect. 



A few Syrphid larvae may be seen now and again, but it is very 

 exceptional, and usually happens where we have concomitant attacks 

 of Apple Aphis, which on being destroyed, the Syrphid larvae take to 

 the Woolly Blight. 



IJarely larval Hemerobiidcc, or Lace Wing Flies, have been found 

 with the pest on exposed shoots. 



Small dipterous lame of the genus Pipiza were found feeding on 

 the root form in 1899 in some numbers. 



Now and again a Nemocoris is found sucking their juices, 

 and a few spiders and Harvest-Men (Phalangidce) now and then 

 take them. 



With the exception of birds, natural checks are of no importance. 



