Insects Injurious to ike Apple. 



159 



green all over and the aliduniei^ lavgt.ir and l)i'oad(M- tliau tlie tlnirax, 

 and small rudiments of wing bnds a])pL'ar (Fig. 1-!'.l). 



This is the first nyrnphal or jmpal stage. Lil^e tlie larva, it lias a 

 long thread and waxy glubiile and becomes still further covered with 

 white waxy threads and tine curled liair-like particles. 



The third change of skin takes place in from eight to fifteen days 

 and the wing rudiments liecome more pronounced. After 1 his moult 

 the filament and fine curly threads are nrostly pale blue. 



The nymphal stages are usually Ibirnd on the leaves, the fine 

 filaments seem to hold two leaves together and thus shelter the 

 " suckers." (Iften several nymphs are 

 found close together between the two 

 leaves. 



Previous to the moult, the nymph 

 fixes its beak firmly into the leaf and 

 then the skin splits and the winged adult 

 emerges and leaves its cast skin firmly 

 attached to the leaf (Fig. 130). 



The whole cycle, from the hatching of 

 the egg to the bursting forth of the imago, 

 takes from four to six weeks. 



The colour of the pupte varies, those 

 found between the lea^■es are yellower 

 than those which are free on the surface, 

 which are normally green. Tlie antennte 

 are very marked, being darker at the tips 

 wliich are bifurcated, the same as in the 

 ^\•inged adults. 



As far as we know at present the 

 apple is the sole food plant of this 



Tsylla. One year 1 found numliers of it on a hawthorn hedge 

 near some apple trees in my garden, together with some /%//'^ 

 ci'Kfa'ifi, but I find they do not breed on the hawthorn and that the}' 

 evidently only go there for teniporai'y shelter. Thej- may also lie 

 found in the winged state on pear and plum and currants when 

 mixed with apple, but they are there only as casual visitors and not 

 for depositing their e,ggs. As soon as the male lias fertilised tlie 

 female he dies, but tlie fcanale lives for some days after. 



FKi. lil:!.— VOUNG 

 JiUI'KKl: W.UTIXC 



,AK\.K "F AIT'I.E 

 rii KN'l'KK BUI'S. 



I'llEVENTIOX AN 1 1 Tl!E,VTJIEXT 



Tlie prevention of the Apple Sucker is no easy matter, owing to 

 tlieir hatching out irregularly. Spraying to kill the young is very 



