Influence of the Temperature Degrees on the Biological Aspects of Cotton Mealybug Phenacoccus solenopsis Tinsley, (Hemiptera: Pseudococcidae) on Hibiscus Plants

Abstract

The aim of this study shed light on the influence of two constant temperature degrees, 25±1°C, 30±1°C and fluctuate laboratory temperature ranged from 21.9±3.19°C to 31.7±3.91°C with an average of 26.8±3.5°C., on certain biological aspects of the cotton mealybug Phenacoccus solenopsis Tinsley (1989) (Hemiptera: Pseudococcidae). The results showed that the total life cycle of the solenopsis mealybug was shorter for females compared to males and it was significantly affected by the tested temperature degrees, the females lasted 17.0±1.8, 14.7±1.5 and 20.6±2.4 days at 25±1°C, 30±1°C and fluctuated temperatures 26.8±3.5°C, respectively, Whereas the male life cycle required 18.8±1.5, 15.9±2.1 and 21.9±2.9 days at 25±1°C, 30±1°C and 26.8±3.5°C, on the Hibiscus plant leave (China rose), Hibiscus rosa-sinensis L. respectively. The generation periods also significantly affected by the tested temperatures it was 28.2±3.0, 23.9±2.1 and 20.1±1.2 days for the insects reared at 25±1°C, 30±1°C and 26.8±3.5°C, respectively. Adult males lived shorter than females; the adult female's longevity required 24.9±2.2, 22.2±3.2 and 24.3±2.0 days at 25±1°C, 30±1°C and 26.8±3.5°C, respectively, while adult males longevity lasted 2.5±1.1, 2.3±0.9 and 2.3±0.8 days at 25±1°C, 30±1°C and 26.8±3.5°C, respectively. The fecundity of the solenopsis mealybug also significantly affected by the tested temperatures; the females laid 349.3±85.8, 382.0±49.9 and 309.8±69.0 Eggs/female at 25±1°C, 30±1°C and 26.8±3.5°C, respectively. Sex ratio between males and females of P. solenopsis are not affected by the different tested temperatures. From the obtained results, it could be concluded that the cotton mealybug, lasted short time for the development at constant temperature degree of 30±1°C than the other temperatures of 25±1°C and fluctuated temperature of 26.8±3.5°C.