The performance of the aphid A. pisum, reared on nine P. sativum varieties, was assessed using mean relative growth rate of aphids (MRGR), number of pigmented embryos (NPE) and pre-reproductive adult weight. The result indicated that MRGR as a measure of growth for A. pisum should be used with caution particularly if assessed over a time as short as three days. Over the range of varieties used, there was a highly significant relationship between pre-reproductive adult weight and NPE. The latter, providing an estimate of initial reproductive rate, is a valuable method for the fast assessment of A. pisum performance on its host plants. The results indicated that the variety Onward had the highest antibiotic resistance, and other varieties were almost equally susceptible.

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