关键词: 二疣犀甲, 形态学, 生物学特性, 发育历期, 雌雄二型, 性比

Abstract:  【Aim】 To observe systematically the biological and morphological characteristics of Oryctes rhinoceros in the laboratory. 【Methods】 The morphological characteristics and development process of O. rhinoceros fed by the mixture of cow dung and dust (4∶1, m/m) under the laboratory conditions of 26±1℃, RH 75%-95%, and photoperiod 10L∶14D were recorded every 6 hours. and the body length, body width and body weight at different developmental stages were measured. 【Results】 O. rhinoceros is an insect that undergoes complete metamorphosis, and has four developmental stages in the whole life, i.e., egg, larva, pupa and adult. The average egg period, the whole larval period, the pre-pupal and pupal periods of O. rhinoceros were 8.88, 156.82, 9.45, and 33.75 d, respectively, and the generation period was 326 to 455 d. The body length and weight of the 1st instar larvae were 4.16 mm and 0.64 g, those of the 3rd instar larvae were 65.66 mm and 12.14 g, and those of pupae were 51.62 mm and 9.72 g, respectively. Adults emerged at the early stage were larger in body size than those emerged at the late stage. The significant difference was manifested (P≤0.05) in morphological characteristics, such as body length, body width, horn length and weight of adults at different emergence time. O. rhinoceros adults showed sexual dimorphism, and the sex ratio (female to male) of the offsprings was 1.23∶1. 【Conclusion】 O. rhinoceros is an important pest of coconut palm plants, and its biological and morphological studies are the basis of selecting pest prevention and control technologies. The results of this study may provide a theoretical foundation for O. rhinoceros control.

Key words: Oryctes rhinoceros, morphology, biological characteristics, developmental duration, sexual dimorphism, sex ratio