LONGEVITY, FECUNDITY, AND FERTILITY OF THE RED PALM WEEVIL, RYNCHOPHORUS FERRUGINEUS OLIVIER (COLEOPTERA: CURCULIONIDAE) ON NATURAL AND ARTIFICIAL DIETS

Abstract

Life parameters including pre-oviposition period, oviposition period, larval and pupal periods, adult male and female development times, and generation span, were obtained for the red palm weevil, Rhynchophorus ferrugineus Olivier, reared on artificial diets of oat, potato, pineapple, and palm fiber sheath, and on natural diets of sugarcane, palm heart, and palm leafbase. Significant differences in the duration of all life parameters were found when fed on various diets. The pre-ovipositional periods ranged from 3.15 to 3.61 d, while the oviposition periods ranged from 3.2 d to 3.8 d. The developmental times of larvae ranged from 70.8 d to 102.2 d, while the development time of pupae ranged from 16.1 d to 22.2 d. The developmental time of adults previously reared on natural diets were longer than those fed on artificial diets. Differences in the development time occurred between males and females reared on different diets, except on sugarcane and palm leafbase. The generation span ranged from 93.2 d to 131.3 d. Significant differences in the average number of eggs deposited per female, previously reared in their larval stages on various diets, ranged from 68.2 eggs to 185.2 eggs, while the average number of eggs deposited per female per day ranged from 1.28 eggs to 3.03 eggs. The percentage of hatchability (viability of eggs) ranged from 74.3% to 93.3%. The mean total number of eggs laid by females, eggs deposited 30 d after one full copulation with males of similar age, and rate of egg hatch decreased significantly with increasing weevil age, and ranged from 65.5 eggs (1-d-old female) to 43.5 eggs (45-d-old female). The rate of egg hatch, also decreased significantly with increasing weevil age, and ranged from 75.8% (1-d-old weevils) to 47.4% (45-d-old weevil). The short copulatory period was adequate for insemination of the female during copulation. Feeding of R. ferugineus on different diets resulted in different life parameters.