The Infestations of Asiatic Palm Weevil (Rhynchophorus vulneratus Panzer) in Coconut Palms in Yogyakarta Special Region, Indonesia (Early View)

Abstract

The Asiatic palm weevil, Rhynchophorus vulneratus, is a major insect pest of coconut palms in Indonesia. This pest poses a significant threat to coconut palm populations, causing substantial economic losses. However, information regarding the altitude preferences of R. vulneratus remains limited. This research aimed to investigate the infestation and study polymorphism of R. vulneratus at varying altitude levels in Yogyakarta, Indonesia, which encompasses habitats from 0 to 1,000 m above sea level (asl). The study was conducted across five altitude levels during the rainy, transition, and dry seasons. R. vulneratus populations and habitat preferences were assessed using aggregation pheromone traps at each site. Color polymorphism was studied by observing the pronotum patterns of captured individuals and using gen CytB to identify R. vulneratus. Results indicated that altitude significantly influences the abundance and diversity of color morphs of R. vulneratus. The weevils exhibited a preference for habitats at 0-300 m asl. Rusty red morphs were more prevalent (64.94%) than red stripe (30.52%), and intermediate morphs (4.55%). The red stripe morph displayed higher pronotum pattern variation (38 variations in males and 29 in females) than the rusty red morphs (30 variations in males and 28 in females). Molecular analysis based on the genetic distances confirmed that red stripe, rusty red, and intermediate morphs belonged to R. vulneratus. Its populations tended to increase during the dry season (June–September, with 2,417 individuals captured) and decrease during the wet season (February–April, with 151 individuals captured). The peak capture rate occurred in September during the dry season (1,025 individuals).