Population dynamics of Aleyrodes proletella L. (Hemiptera: Aleyrodidae) and its parasitoids in Düzce Province of Turkey

Abstract

Cabbage whitefly, Aleyrodes proletella L. (Hemiptera: Aleyrodidae), causes severe damage to Brassica vegetables. This study was conducted to evaluate the seasonal population dynamics of A. proletella and its parasitoids throughout the 2016 and 2017 growing seasons in Duzce Province in Turkey. To estimate whitefly density and parasitism rates, collard leaf samples infested with whitefly were collected from fields where no pesticides were applied. Collard leaves were cultured for emergence of the adult parasitoids, which were identified as Encarsia tricolor Forster (Hymenoptera: Aphelinidae) based on morphological and molecular characteristics. Seasonal mean densities of A. proletella ranged from 11.20 to 19.30 nymphs/leaf in 2016 and from 15.19 to 86.66 nymphs/leaf in 2017. The highest parasitism rates were 6.46% and 24.79% in 2016 and 2017, respectively. Whitefly nymphs peaked in July and August during both years. The first parasitized whitefly nymphs were observed in July, and maximum parasitism rates occurred in the second half of August during both years. These findings provide significant contributions for studies involving the conservation of parasitism of A. proletella.