Effect of temperature on development, mortality, fecundity, and reproduction of Aphis rumicis L. (Homoptera: Aphididae) on broadleaf dock ( Rumex obtusifolius ) and Swiss chard ( Beta vulgaris vulgaris var. cida )

Temperature effects on developmental period, survival rate, and reproductive capacity of Aphis rumicis L. were studied on Broadleaf dock and Swiss chard at four constant temperatures (17.5°C, 20°C, 22.5°C, and 25°C). The developmental time of immature stages ranged from 10.9 days at 17.5°C to 6.5 days at 25°C on Broadleaf dock, and 11.8 days at 17.5°C to 6.5 days at 25°C on Swiss chard. The total percentage of survivorship of immature stages varied from 54.2% and 67.6% 17.5°C–25°C on Broadleaf dock, and 49.7% and 62.4% at 17.5°C–25°C on Swiss chard. The largest r m value occurred with 0.2845 at 25°C on Broadleaf dock and with 0.2785 at 25°C on Swiss chard. The results obtained on this study indicated that Swiss chard was a less favorable host of the A . rumicis than Broadleaf dock. The optimal temperature for A . rumicis growth, developmental time, and reproduction was 22.5°C–25°C.