KLM LK. \!< CTRL AND WOOLLY AIM'LL APHID. 



LIFE CYCLE OF WOOLLY APHID OF APPLK. 



ELM: Primary Host. 



EGGS. 

 (Under bark all winter) 



STEM-MOTHER. 



(first generation in leaf curl. 

 Apterous viviparous females). 



S E( 'ON I) GEN ER ATTOX . 



(apterous viviparous females 

 in leaf curl ). 



APPLE: Alternate Host. 



NYMPHS. 



(From hibernating forms on 

 roots, etc.) migrating to 

 trunk or branches in early 



spring. 



-EVERAL GENERATIONS. 



SPRING MIGRANTS Migrate to apple . 

 (third generation. Alatc viviparous). 



FOTRTH GENERATION. 



(apterous viviparous females) 



ST M MICK C.EXEKATIOX 



ox EF.M P.ARK. 



Migrate to elm 



APTEKorS oYII'AKors FEMALE 

 AMI AI'TEROTS MALES. 



FIFTH GENERATION. 



(apterous viviparous females). 



I'ALL MIGRANTS. APTEROTS \'!VIPAROUS 

 PARTHENOGENETIC 



Alate viviparous FEMALES, mature in 

 parthenogenetic Sept. -Oct. 



females, mature 

 Sept. -Oct. scxuparae. 



HIBERNAT] N"G FORM: 

 OX APPF.E ROOT. 



