Abstract
The reproductive behavior and development of red palm weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera Dryophthoridae) was studied in laboratory by rearing it on five popular date palm cultivars, viz., 'Barhi', 'Beraim, 'Ruthana,' 'Sukkary' and 'Wannana', and sugarcane with an objective to determine the host-plant effects. Observations were made on the number and rate of eggs laid, incubation period, hatching percentage, larval and pupal developmental periods, adult longevity and sex ratio. The cultivars, Sukkari.,, Ruthana. and, Barhi. favored oviposition and development of red palm weevil comparatively. The, Ruthana. cultivar recorded highest number of eggs / female (392.50 +/- 1.558 eggs) at the highest rate (4.17 +/- 0.021 eggs / female / day), the longest pupal developmental period (19.30 +/- 0.259 days) and the strongest female bias in the sex-ratio (56: 48 per cent). The, Sukkary. cultivar showed longest male (111.20 +/- 1.426 days) and female (120.80 +/- 0.188 days) lifespan, fastest completion of larval period (29.66 +/- 0.132 days) and highest (96%) egg-hatching percentage. Adults from, Barhi. recorded second longest (male 104.10 +/- 0.883 and female 98.90 +/- 0.613 days, respectively) lifespan. On the other hand, 'Beraim' and, Wanana. cultivars showed developmental delay in the lifecycle of red palm weevil. Both the cultivars showed lowest egg-hatching percentage (92%), the lowest adult longevities (less than 81 days), lowest egg-laying (less than 240 eggs) in a lifetime and longest duration of immature stages (over 70 days). The observations from sugarcane revealed lower oviposition and hatching percentage, and longer period for adult emergence than the date palm cultivars.