AGE AND REPRODUCTIVE STATUS OF PHEROMONE TRAPPED FEMALES OF RED PALM WEEVIL, Rhynchophorus ferrugineus (Olivier) (COLEOPTERA: CURCULIONIDAE)

Morphological changes in the ovarian system of red palm weevils,  Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), reared on coconut  frond piece, were studied at Department of Entomology, UAS, GKVK, Bangalore during  2001 as a function of adult age and reproductive status. Development of ovarian system  was studied in both unmated and mated females after dissection at regular intervals.  Number of eggs were counted in both lateral and common oviducts. Higher numbers of  eggs were found in mated females of 10 to 25 day old weevils. Females were graded into  four categories viz., virgin or umnated, gravid, laying and spent females, based on the  ovarian development, number of eggs in lateral and common oviducts and the quantity  of accumulation of fat globules in the abdominal cavity. Pheromone trapping using  synthetic ‘Ferrolure’ was done in red palm weevil infested coconut gardens at Tumkur district of Karnataka. Pheromone trap captured weevils were brought to laboratory,  dissected and reproductive status was identified based on the grading of laboratory  reared weevils. Most females captured in the pheromone traps were gravid (45-70%) which  had initiated egg development followed by virgins (14-25%). The percentage of laying  and spent females caught in the traps was very low. This method forms a basis for  determining the reproductive potential of pheromone trap caught weevils which otherwise  cause a great damage in the coconut gardens.