D3292: Population dynamics of leafhopper Jacobiasca lybica (Hemiptera: Cicadellidae) and its incidence on citrus ages in the Moulouya area of Morocco

The cotton leafhopper (Jacobiasca lybica) is one of the polyphagous species which is considered one of the serious pests in vineyards and recently in citrus crops in Morocco where it started to affect seriously the citrus fruits quality. The bio-ecological parameters of this leafhopper are poorly understood especially that no study had been done before under Moroccan conditions. The population dynamic and incidence of J. lybica were monitored for the first time on different citrus ages in a citrus crop during 2019 and 2020 in Berkane region of Morocco, using five yellow sticky traps for each experimental unit that were collected weekly for the identification and counting of leafhopper adults. Our results indicated that seven to eight peaks of adult flight were observed, while eight generations should have been predicted according to degree-days (DD) obtained during 2019 until September, furthermore, five leafhopper adult peaks were observed in young trees during 2019, while seven peaks were found on old citrus orchards. However, during 2020, seven to eight peaks of adult flight were observed from July to December with a total of ten generations predicted by DD, and eight leafhopper adult peaks were clearly observed in young trees, and seven peaks were found on old citrus orchards. Citrus fruit incidence symptoms started to appear during September and revealed the abondance of leafhoppers on old trees (12% of citrus fruit with incidence symptoms) than the young ones (8%).