122 Food Plants of Aphis rumicis 



29. 5. 13. The aphis infests the stem in vast numbers, almost along the whole of 

 its length, also beneath the leaves along the mid-ribs. They are big, 

 healthy individuals, the winged forms being much larger than those 

 present on Euonymus B. Most of the winged forms are actively 

 walking on the muslin cover as though wanting to escape. 

 4. 6. 13. Enormous numbers of winged forms are now present, crowding round 

 the top of the musUn cover, and not on the plant at all. It is 

 noticeable that during the progress of the uifestation, the colonies 

 of apterous forms first collected at the apex of the young growing 

 stem, and gradually extended towards the base, until the whole 

 stem was covered. Many also along the mid-rib, and main veins 

 of the leaves. 



24. 6. 13. Plant dead, all the aphids dead. 



Plant No. 2. Rumex sanguineus. 



Infected from Euonynms B with four apterous viviparous females. 



Several aphids produced. 



Several colonies present on this plant, also nymphs of winged forms 



produced. Colonies present on mid-rib ))eneath the leaves. 

 A few winged forms produced. 



Now faiiiy heavily infested, but numbers not so great as m case of No. 1 ; 

 there are fewer winged forms present. 

 4. 6. 13. Aphids not nearly so numerous as in No. 1 ; chiefly collected at top of 

 the stem, but one colony forming half-way down. A few winged 

 forms present, walking on the muslin cover. Several colonies 

 beneath the leaves, on the mid-rib and veins. 

 16. 6. 13. Plant fauly heavily infested ; numbers of w. v. $'s, which are crowding 

 round the top of the muslin cover. Infestation not so heavy as No. 1. 

 28. 6. 13. Plant heavily infested, vast numbers of winged forms actively crawling 

 over the muslin cover. Many apterous forms clustered along the 

 length of the stem, and beneath the leaves, along the mid-rib, many 

 of these very small. 

 8. 7. 13. Plant dead, aphids all dead. 



Plant No. 3. Broad Beans. 



Infected from Euonymus B with five w. v. $'s. 



A few aphids produced, but it would appear that the w. viviparous 

 females from B are weak and are not producing happily. Rein- 

 fected with 3 w. V. $'s from B. 

 Only a few aphids present. Reinfected with four w. v. $'s from Euony- 

 nms B. 

 24. 6. 13. Many colonies produced, situated on the upper part of the stem and in 

 axils of the leaves. A few nymphs of winged forms present. Aphids 

 big and healthy. 

 28. 6. 13. Winged forma present. 



