Insights into the cultivable gut-associated bacterial community of the red palm weevil (Rhynchophorus ferrugineus) from Al Ahsa, Eastern Saudi Arabia

The red palm weevil ( Rhynchophorus ferrugineus ) is a major pest of date palms in the Al Ahsa region, Saudi Arabia. This study aimed to characterize the cultivable gut-associated bacterial community of R. ferrugineus and to provide preliminary insights into their potential functional attributes. Gut bacteria were isolated from larval and adult stages using culture-dependent methods and identified based on 16S rRNA gene sequencing followed by phylogenetic analysis. The obtained isolates included several bacterial taxa, such as Klebsiella, Citrobacter, Acinetobacter calcoaceticus, and Halomonas spp., along with Gram-positive species such as Enterococcus faecalis and Staphylococcus equorum. Selected isolates were subjected to qualitative screening for enzymatic activities, including cellulolytic, xylanolytic, amylolytic, and proteolytic activities, based on clear-zone formation. In addition, biofilm-formation potential was qualitatively screened using Congo Red Agar. Overall, this study provides a culture-dependent characterization of gut-associated bacteria in R. ferrugineus. These findings offer baseline information on cultivable microbial associates and support future investigations using advanced molecular and functional approaches.