Determining some biological parameters of Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) on cotton mealybug and the rate of parasitism in field conditions

Abstract

Aenasius arizonensis (Girault) (Hymenoptera: Encyrtidae) is the primary parasitoid of Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). Some biological parameters of this parasitoid have not been fully understood. Therefore, this study was conducted to determine biological parameters of A.arizonensis at 25 °C, 65% R.H, 16 : 8 L : D with Age-stage Two-sex life table and effectiveness of this parasitoid in field conditions in Turkey. The results showed that pre-oviposition, oviposition and post-oviposition periods of A. arizonensis were calculated as 1.5, 26, and 3.1days, respectively. In addition, total mean longevity was determined as 31 days for female, and 18 days for male individuals. Moreover, total mean fecundity and daily mean fecundity were also found as 83 mealybugs/female, and 4.1 mealybugs/female/day, respectively. The intrinsic rate of increase (r), net reproduction rate (R 0 ), finite rate of increase (λ), gross reproductive rate (GRR), and mean generation time (T) were found 2 0.135, 41.25, 1.144, 60.90, and 27.57, respectively. Field studies have been conducted to determine the efficacy of this parasitoid in 2018 in Adana and Mersin / Turkey. The parasitism rate was risen to 78 -80% in September, both in Adana and Mersin provinces, attributed to early releases in August, 2018. In conclusion, higher parasitism rates showed that this parasitoid can be successfully used against cotton mealybug as an effective biological control agent.