Laboratory investigations on development, longevity and reproduction of the European red mite, Panonychus ulmi (Koch) (Acari: Tetranychidae) at two high temperatures
2002
Khan, I.A. | Sengonca, C. (Bonn Univ. (Germany). Dept. of Entomology and Plant Protection)
The European red mite, Panonychus ulmi (Koch) (Atari: Tetranychidae) is an important pest of apple in massy countries of the world. Biological data on its development, longevity and reproduction was insufficient at and above 25 degree centigrade. The present experiments were, therefore, designed to obtain experimental data on these parameters in the life history of P. ulmi at 25 and 30 degree centigrade temperatures. The results showed that mean duration frosts egg to adult stage decreased from 18.1 to 12.8 days for females and from 17.9 to 12.2 days for males with increasing temperature. Mean duration of pre- oviposition period decreased from 3.9 to 3.2 days and oviposition period from 13.9 to 10.6 days. Mean longevity of females decreased from 17.8 to 13.8 days and of males from 13.9 to 11.9 days. Mean total fecundity decreased, from 80.0 to 51.0 eggs/female while mean daily fecundity decreased from 5.7 to 4.7 eggs/female. Female to male ratio was 3:1 at 25 degree centigrade and 4:1 at 30 degree centigrade. The percentage of survivorship was higher at 25 degree centigrade with 94.7% while it was 74.8% at 30 degree centigrade.
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