Resistance of different almond varieties to Eurytoma amygdali (Hymenoptera, Eurytomidae)

Eurytoma amygdali Enderlein is one of the most important pests of almond trees in Iran. In this investigation, seven new and commercial almond varieties and genotypes were evaluated in East Azarbaijan province. The results showed that there was a significant difference among the different varieties of almonds (P<0.01) in terms of infestation percentage of almond fruits. Azar and Shokoofeh varieties and genotype ALC721 with an average of more than 50% infestation had the highest infestation percentage among the tested varieties, whereas Ferragnes, Sahand, A200 and Eskandar with less than 10% infestation had the lowest infestation percentage to this pest. study the number of wasp stings in the antixenosis test showed that Azar variety with an average of 2.07±0.96 had the highest wasp stings, whereas Sahand and Ferragness (with the mean of 0.61±0.43 and 0.60±0.51, respectively) had the lowest wasp stings. The highest percentage of fallen fruits due to wasp stings were observed in Azar, Shokoofeh, Eskandar, Ferragnes and ALC721 with an average of more than 35% and the lowest percentage of fallen fruits observed in A200 and Sahand with an average of less than 10%. The results of olfactory test showed that the highest number of female wasps was attracted to Eskandar, Azar, ALC721 and Shokoofeh varieties, whereas the lowest was attracted to Sahand and Ferragnes varieties. In general, the results of this study showed that Azar and Shokoofeh varieties and genotype ALC721 were the most susceptible varieties to almond seed wasp among the studied varieties. Ferragnes and Eskandar varieties, despite the high percentage of fruit drop due to wasp stings, had a low infestation percentage of almond fruits at the end of the season. Sahand and A200 varieties with the lowest percentage of fruit drop due to wasp stings and also the lowest infestation percentage of almond fruits at the end of the season were the most resistant varieties to the almond seed wasp.