Some biological aspects of the red palm weevil, rhynchophorus ferrugineus (oliv er) as influenced b y rearing on certain palm varieties, temperature and relative humidity

Certain biological aspects of Rhynchophorus ferrugineus (Olivier) (larval and pupal periods, male and female longevity as well as female fecundity of eggs) were studied for two successive years from 22/6/2005 to 22/6/2007 on five varieties of palms (Hayani, Eglany, Amry, Zaghlool date palms and Pritchardia ornamental palm) under laboratory conditions. The obtained data revealed that the durations of larvae and pupae were high significantly affected by the tested varieties during the 1st and 2°d generations. Longevity of both males and females insignificantly and high significantly influenced with palm variety during the 1st generation, but during the 2nd one the opposite is true. The highest mean numbers of eggs/female (107.33 and 127.50) were deposited in case of Amry and Zaghlool date palm varieties in the 1st and 2 generations, respectively. The fecundity of females resulted in case of Pritchardia ornamental palm variety was the least during the two aforementioned generations. Duration of larvae significantly correlated with both temperature and relative humidity for all tested varieties during the three generations completed through the two successive years of the present investigation. Pupal duration showed significant correlations with both temperature and relative humidity during the 1st generation with the exception of those in respect to Zaghlool date palm (temperature) and Pritchardia ornamental palm (relative. humidity) that proved to be insignificantly correlated. The correlation between temperature as well relative humidity and longevity of both males and females differed according to the tested varieties. During the 2 generation, mean number of eggs/female significantly correlated with temperature and relative humidity in case of Zaghlool date palm variety. Mean complete developmental period positively and high significantly correlated with temperature during the three generations with the exception of that concerning the first generation which showed a negative relationship. The correlation was highly significant with relative humidity during the three generations, except with Eglany and Amry date palm varieties during the 2 generation that proved to be not significant.