One of the yellowing diseases that affects melon (Cucumis melo) crops cultivated under plastic greenhouses in southern Europe is caused by a closterovirus transmitted by the greenhouse whitefly Trialeurodes vaporariorum. A Cucumis melo var. agrestis accession shows a certain level of resistance to that virus. Under free‐choice conditions, the reproduction of T. vaporariorum on this accession was significantly lower than on the susceptible control accession C. melo cv. ‘Bola de Oro’, and this suggests that T. vaporariorum prefers to colonize other accessions before C. melo var. agrestis. Under no‐choice conditions, we observed that T. vaporariorum reproduction on C. melo var. agrestis was less than on the susceptible controls. The results showed the participation of both antixenosis and antibiosis resistance mechanisms against T. vaporariorum in C. melo var. agrestis. It is difficult to cultivate melon completely free from T. vaporariorum and yellowing disease. However, success in breeding commercial melon cultivars which incorporate the antixenosis and antibiosis found in C. melo var. agrestis together with biological or chemical insect control, or a combination of these, would reduce the insect population and, therefore, the melon‐yellowing disease would occur later and in less severe form.

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