136 



Insect Pests. 



The Rosy Apple Aphis. 



(Apliis sorbi. Kaltenbach.) 



This species is often found with Apliis pomi, and is frequently 

 confused with it even by authorities such as Buckton, whose figure 

 of the apterous viviparous Aphis mali (pomi) is really this insect. 

 It works in a similar way to the former, but seems to curl up the 

 leaves more tightly, and to give them a blistered appearance, the 

 attacked portions often having a rosy and pallid hue. Unlike A. 



pomi, it does not pass all the 

 year on the apple, for in June 

 and early July it migrates 

 from the apples and comes 

 back again in the autumn. 

 To what plant they migrate 

 is not yet known. They 

 have been found on the haw- 

 thorn (Cratccgus oxycantlut), 

 the pear and on Sorbus 

 aucuparia, Sorbus domesticus 

 and Sorbus torminalis. I 

 have frequently found it on 

 the hawthorn, but at the 

 same time as when observed 

 on the apple. 



In colour it is subject 

 to much variation, unlike 

 A. pomi and A. fitchii. 



The " stem mother," or 

 apterous viviparous female, is at first mottled with green and 

 yellow, laterally bluish, with a rusty tinge around the bases of 

 the cornicles, but she gradually becomes dull bluish to black 

 or slaty-grey, or purple, covered with meal ; in form this stage 

 is globular. The larvae vary but are usually yellowish-green, 

 mottled with yellowish, head pale, cornicles blackish and legs 

 blackish, becoming bluish at the sides with pale yellowish bases. 

 The apterous viviparous females are smaller than the stem mother, 

 rusty red to almost pink, with brown marks on the sides of the 

 abdomen and on the thorax ; tapering cornicles, dusky at the apices, 

 yellow at their base ; later they become dusky purplish-black, dusky 

 red basally and covered with white meal. The pupa varies from 



[F. Edenden. 



FIG. 109. "STEM MOTHER" (VIVIPAROUS FEMALE) 



OF Aphi* sorbi, KALT. 



(Greatly enlarged.) 



