Biological response of red palm weevil ( Rhynchophorus ferrugineus , Olivier) (Coleoptera: Curculionidae) on six different varieties of date palm

The red palm weevil is a notorious insect pest of the palm family around the palm-growing regions of the world. This study investigated the biological effects of six commercially important date palm varieties viz. Dahki, Muzaft, Aseel, Gulistan, Begum Jungi and Fasley on red palm weevil. The newly emerged larvae were cultured on soft portion of the stem of selected varieties in plastic boxes at controlled conditions between 27 ± 2 °C and 65 ± 2% R.H. in incubators. The observations were documented on the number of eggs laid, fecundity, larval and pupal developmental periods, adult life span and sex ratio of red palm weevil. The Dhakki variety was found as the most susceptible having maximum number of eggs hatching (9.5) and weight losses (8.90 g) whereas; Fasley variety was found least susceptible having least egg hatching percentage (8.47) and weight losses (2.94). The maximum total larval developmental duration of 87.2 days was recorded on the variety Fasley which decreased to 64.8 days when red palm weevils were cultured on Dhakki variety. The maximum survival was recorded on variety Dhakki while the minimum survival was recorded on the variety Fasley. The maximum adult longevity (110 days) of female weevils was recorded on variety Dhakki while minimum adult longevity of 50.27 days was recorded on variety Fasley. Our results indicated that varieties significantly influence the development of red palm weevil and can be used as a viable tool for the management of red palm weevil.