Effect of temperature on two-sex life table parameters of Stethorus gilvifrons (Coleoptera: Coccinellidae) feeding on Tetranychus urticae (Acari: Tetranychidae)

Abstract

Stethorus gilvifrons is considered as one of the most important predators of the spider mites. Current study was conducted to examine the effect of temperature on life table parameters of the predatory coccinellid, S. gilvifronsMulstant. The predatory coccinellids were originally collected from sugarcane fields of Khuzestan province and were reared on infected maize plants by Tetranychus urticae Koch at 15, 20, 25, 27, 30 and 34 ± 0.5 ̊C, %60±5 RH and a photoperiod of 16:8(L:D) h. in growth chamber. All of the cohort individuals were died at 38 ̊C. The obtained results showed that temperature significantly affected all developmental time and population growth parameters of the predator. Developmental time of S. gilvifrons decreased with increasing temperatures from 15 ̊C to 34 ̊C. The lowest and highest values of intrinsic rate of increase (r) were 0.0003 (day-1) at 15 ̊C and 0.2052 (day-1) at 34 ̊C, respectively. The values of net reproductive rate (R0) were 1.025, 19.021, 38.58, 43.61, 68.61 and 70.05 (offspring) at 15, 20, 25, 27, 30 and 34 ̊C, respectively. The highest value for total fecundity was 249.52 (offspring) at 30 ̊C. The shortest and longest female longevity were 18.13 and 30.68 (days) at 34 and 25 ̊C, respectively. Mean generation time decreased with increasing temperatures, and the least value was estimated at 34 ̊C. The highest values of gross reproductive rate (GRR) were 283.43 (offspring) at 27 ̊C. Also, the values of finite rate of increase (λ) were 1.0003, 1.050, 1.117, 1.155, 1.182 and 1.227 (day-1) respectively at above mentioned temperatures. The results can be used for biological control of the spider mites and developing a mass rearing system for S. gilvifrons.

Keywords

• temperature
• demographic parameters
• biological control
• stethorus gilvifrons
• spider mite