Evaluation of some melon lines for their resistance against melon aphid,Aphis gossypii Glover

The melon aphid, Aphis gossypii Glover Hemiptera: Aphididae , which has a very wide host range including cucurbit species, causes serious direct and indirect damage to many crops. In both greenhouse and open field melon cultivation in Antalya in southwestern Turkey , the control of this pest generally depends on the use of chemical insecticides, resulting in a rapid increase in resistance to a wide range of insecticides. In the present study, a total of 23 melon lines 22 indigenous and 1 exotic belonging to 2 varieties Cucumis melo var. inodorus and C. melo var. reticulatus were evaluated for resistance to the pest. The study consisted of 2 consecutive work packages; in the first stage, 23 melon lines were evaluated for resistance to A. gossypii by using the antixenosis test method under growth chamber conditions at 26/20 °C day/night temperatures, respectively , with a photoperiod of 16:8 h light:dark ; in the second stage, the most resistant 4 lines PI-414723, UNLU, TK15, and ŞUKRUBEY were evaluated once more for resistance against the pest by using the choice-test method in climate chambers at 26 °C and continuous light. N3, which was found to be the most susceptible line in the first stage of the study, served as the control. Counts were made 30 min, 1, 2, 4, and 8 h after the aphids were introduced into the test arena a 15-cm diameter Petri dish including leaf discs 2.5 cm diameter belonging to the 5 lines. The results of the choice test showed that the aphids preferred the PI-414723 line 2 aphids/disc after 8 h less than the 3 other resistant lines. Additionally, aphids preferred to settle on the susceptible control N3 6 aphids/disc after 8 h during the experiment. Overall, the results suggest that first PI-414723 and then ŞUKRUBEY, TK15, and UNLU may be used for the management of A. gossypii.