INSECTS AFFECTING PARK AM) WOODLAND TREES 



641 



branches of twiys. ^cncralh' mar the Ixisc of Inids or leaf scars. I he (l^^^s 

 rosenihle those of the common apple plant louse, Aphis mali hahr.. 

 thoiiuh they are conslderahly smaller, '{"he \-ouni4 stem mother is hnl 

 slii^ditly larger than the e^Li' arul apjjcars in the latitude of W'ashinj^ton 

 about the middle of .\pril. -She is a dull black color covi;ri:d with a 





'^'^^f^m^^ 



Fip. 174 1! i> r inn )t h i s h a in n m c 1 1 ti i s, 3*1 KC'cr.ition. fourth t-r final stage: 

 a = tl<>rsai view ; /■ ventral view; r—tateriil view . d -(inrsul view, showinj* the 

 arrnnicemcnt of purcs ; r— end of body. (After I'ergandc, U. S, Ucp't Agric. Itiv. 



Kni. 'r»_'''h. '^rr. ■;, i-yn) 



delicate, slighth' bluish secretion and ornamented \vith a waNy secretion as 

 shown in figure 172. .She molts three times, attainm^ maluril\- the middle 

 of May and from then i^roducinLj 4-6 youm.^ till ai)out the miildle of June. 

 The second or winged generation, the young of the stem mother, com^ 



