Probing Behavior of Aphis gossypii on Resistant and Susceptible Muskmelon12

Abstract

Microscopic examination of stylets and sheaths and electronic recording of the probing behavior of the melon aphid on resistant and susceptible muskmelon revealed pronounced differences in probing on the 2 lines. Relative to the susceptible line, ‘Top Mark,’ stylets and sheaths in the resistant line, 91213, had significantly more branches ending in the phloem. Electronic recording of aphid probing revealed that on the resistant plants a significantly greater percentage of the probes led to stylet contact with the phloem sieve cells, but a smaller proportion of the sieve cell contacts resulted in ingestion than was the case on susceptible plants. In addition, the duration of periods of ingestion from the sieve cells was 2- to 3× greater on susceptible than on resistant plants.