138 Aphis rumicis o/i Varieties of Yic'm faha, 



Variety 

 Bohus beans 

 (Sweden) 



Mazagan 



English field 



Heligoland 



Scotch var, 

 Granton 



Winter beans 

 (Dorset) 



Winter beans 

 (Somerset) 



Winter beans 

 (Essex) 



Spring tick 

 (Suffolk) 



Carse beans 



No. of 



variety 



I 



II 



III 



IV 



VI 



VII 



VIII 



IX 



No. of 

 plant 



1 



2 



3 



4 



5 



6 



7 



8 



9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 29 

 30 

 31 

 32 

 33 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 42 

 43 

 44 

 45 

 46 

 47 

 48 

 49 

 50 

 51 

 52 

 63 

 54 

 55 

 56 

 57 

 58 

 59 

 60 



Table I. 



Date in May 

 a. V. $ aphids 



commenced killed 

 producing off 

 13 27 



Stock plant 

 26 



12 

 13 



13 



12 

 13 



13 



13 



14 

 13 



Stock plant 



27 



Stock plant 

 28 

 29 

 28 



Stock plant 

 27 



Stock plant 



27 



20 

 27 

 Stock jilant 



27 



26 

 Stock plant 



27 



Stock plant 

 27 



Stock plant 

 27 



28 

 27 

 Stock plant 



Total 



aphids 



produced 



1275 



1058 



967 



904 



884 



1188 

 1154 

 1068 



992 



632 



978 

 759 

 680 

 636 

 631 



738 

 723 

 622 

 502 

 497 



753 

 677 

 544 

 542 

 441 . 



641 

 630 

 575 

 542 

 430 



656 

 525 

 501 



458 

 426 



541 

 536 

 450 



276 



487 

 413 

 407 

 396 

 391 



650 

 477 

 425 

 349 

 176 



Mean figure 



of infestation 



and probable 



error 



1018±51-3 



1007±511 



737 ±43-7 



016±39-9 



591 ±39-1 



564 ±38-2 



513±36-4 



451 ±38-2 



419 + 32-9 



415±32-8 



