Effect of four commercial barley varieties on life table parameters of Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae)

Abstract

Angoumois grain moth, Sitotroga cerealella (Olivier) is one of the most important pests of stored products and known as factitious host for mass rearing of insect natural enemies. Effect of four commercial barely varieties including Fajr 30, Behrokh, Nik and Yousef on life table parameters of S. cerealella was determined at 26 ± 2 °C, 65 ± 5% RH and a photoperiod of 12:12 h (L: D). Data were analyzed based on the age-stage, two-sex life table theory. The results revealed that there were significant differences among various barely varieties regarding the developmental times, adult longevity and fecundity of S. cerealella. The longest developmental time (56.72 ± 0.29 days) was observed on Yousef. The longest and shortest male longevity were obtained on Behrokh (6.77 ± 0.27 days) and Yousef (5.79 ± 0.16 days). Moreover, female longevity ranged from 6.20 ± 0.18 to 7.23 ± 0.24 days on Yousef and Behrokh, respectively. The highest values of intrinsic rate of increase (r) were estimated 0.0719 ± 0.004 and 0.0717 ± 0.003 day -1 on Fajr 30 and Behrokh, respectively and the lowest values were 0.0539 ± 0.004 and 0.0542 ± 0.003 day -1 on Nik and Yousef, respectively. The longest generation time (T) was observed on Yousef. Furthermore, peaks of reproductive value occurred at ages of 45, 49, 48 and 53 days when reared on Fajr 30, Behrokh, Nik and Yousef, respectively. It can be concluded that Fajr 30 and Behrokh can be used for mass rearing programs of S. cerealella as an alternative host for natural enemies.