t)AViDSON — Biological Studies of Aphis riimicis L. 309 



They produced 11 and 22 females respectively, which were adult on 5. 12. 20 

 and 9. 12. 20. A third w. v. ? produced only sexual ? ? . 



Broad Beans B,„.— 5. 12.20. Infected with a. v. ? from B^. 23. 12. 20. 

 One a. v. $ produced, remainder are w. v. ? ? ; total 20. 



Broad Beans Bi^.— 1. 12. 20. Infected with 10 w. v. ? ? from B,. 

 26. 12. 20. All the aphids produced are sexual ? ? . 



Broad Beans Bj^. — 23. 12. 20. Infected with the one a. v. ^ from Bi„. 

 9. 1. 21. Offspring consists of 10 w. v. ° 5 adult, 2 adult a. v. ° ° , and 

 remainder nymphs of winged forms ; some $ 3' ■ 



Broad Beans B13.— 26. 12. 20. Infected with 10 w. v. 2 j from B,o. 

 1.1.21. Fourw. V. 5 ° have produced young. 12.1.21. All offspring are 

 oviparous 5 + ; some are adult. 



Broad Beans B,4.— 10. 1. 21. Infected with 2 a. v. ° % from B,,. 5. 2. 21. 

 w. V. 5 $ (sexuparae), $ $ , and 4 a. v. ° ^ produced. 



Broad Beans B.s— 10. 1. 21. Infected with 5 w. v. ° ° from B,j. 24. 1. 21. 

 18 oviparous ^ ? produced. 



Broad Beans B.^.— 24. 1. 21. Infected with 4 a. v. ? ? from B^. 3. 2. 21. 

 3 c? c? ; several w. v. ^ ^ ^^^'^ 1 a. v. J produced. 



Broad Beans B,,.— 5. 2. 21. Infected with 5 w. v. ° ° from B^. 21. 2. 21. 

 Only one w. v. ^ reproduced, and gave 6 oviparous 5 + ■ 



Broad Beans Bis. — 3. 2. 21. Infected with the 5 a. v. J + fi'om Bio. 

 23. 2. 21. 2 a. V. ° o ; several <? $ ; several w. v. 5 $ present. 19. 2. 21. 

 The 5 original a. v. 5 mothers put on a new plant, and on 2. 3. 21 they had 

 produced 3 a. v. J $ , some <? $ , and w. v. ^ ? • 



Broad Beans Bi,.— 23. 2. 21. Infected with 5 w. v. ? ° from Bie. 10. 3. 21. 

 All oviparous ^ + produced. 



Broad Beans Bw. — 2.3.21. Three plants infected each with one a. v. J 

 from B18. 26. 3. 21. 5 a. v. ? ?, one $ , and 40 w. v. ? ? produced. 



(f) Uuonymus JSuropaeus Infected frotn Broad Beans. 



Euonymus Eg. — 16. 6. 20. Infected with a. v. ^ ^ > offspring of winged 

 migrants on Broad Beans. 29. 6. 20. Many aphids present, mostly a. v. ^ + , 

 but some w. v. ^ + • 



JSuonymus E,. — 10. 7. 20. Infected with 25 w. v. ^ ? from Beans B. 

 18. 7. 20. Many colonies- produced beneath the leaves. 5. 8. 20. Aphids 

 small size, dark colour, many winged forms ; infestation heavy ; plant has no 

 young growth. 



Euonymus Eg. — 19. 8. 20. Infected with 15 w. v. 5 + from Beans B4. 

 31. 8. 20. Many aphids produced, some adult a. v. ° ° 14. 9. 20. Plant 

 heavily infested ; many aphids wandering over the plant and muslin cover. 



