Rate of Reproduction of the Pea Aphid on Different Alfalfa Plants*

Publisher Website
Google Scholar
Abstract
A study was made in 1934-1935 of 354 resistant and susceptible alfalfa plants on which nymphs of the pea aphid, Illinoia pisi, were caged. At the end of 10 days the av. number of progeny per parent and the % mortality for each plant were calculated. The optimum temp. for pea aphid reproduction and life was several degrees higher on alfalfa plants that appeared to be susceptible (s) under field conditions than on plants that appeared to be resistant (r). The pea aphid re-produced more rapidly and the mortality was less on s plants than on r. Aphids reproduced more rapidly on selfed progeny of s selections than on the selfed progeny of r selections. Some r plants furnished satisfactory food for aphid reproduction. These plants may be resistant because of their ability to withstand the feeding of aphids. When aphids were confined to flowering and vegetative branches of the same plant, they reproduced faster on the flowering branches. Although in this summary of the expts. plants have been classed as resistant or susceptible, there was considerable range in mortality and rate of reproduction within the 2 groups.

This publication has 1 reference indexed in Scilit: