Comparative analysis of gut and ovarian microbiota in Dactylopius opuntiae (Hemiptera: Dactylopiidae) from distinct Moroccan regions

Abstract

Introduction Investigating the hidden microbial world within insect hosts yields new insights into their biology, ecology, and adaptation. Dactylopius opuntiae (Cockerell), a major invasive pest of the cactus Opuntia ficus-indica , causes severe economic and ecological damage in Morocco and other arid regions. However, little is known about its associated bacterial microbiota and how it varies across environmental gradients. This study explored the bacterial diversity of D. opuntiae and evaluated how it varies across tissue types, developmental stages, and contrasting environmental regions. Methods We characterized bacterial communities in two tissue types (gut and ovary) of adult females and in whole-body samples of nymphs, collected from two ecologically contrasting regions of Morocco: Marrakech (arid, semi-desert climate) and Al Hoceima (humid, Mediterranean climate). Using 16S ribosomal RNA (rRNA) gene sequencing, we evaluated differences in diversity, composition, and relative abundance across regions and developmental stages. Results Sequencing generated approximately 2.84 million reads across all samples, of which 91.9% were retained after quality filtering and contaminant removal, and 91.2% were successfully classified to bacterial taxa. Our results revealed clear geographic structuring of the microbiota. In insects from Marrakech, the adult gut and ovary harboured comparatively lower bacterial diversity and were dominated by Pseudomonadota , whereas whole-body nymph samples were dominated by Bacillota (>70% relative abundance). In contrast, samples from Al Hoceima showed consistently higher bacterial richness across stages and tissues, with Pseudomonadota accounting for approximately 60–90% of reads. Differential abundance analysis identified several taxa with nominal tissue- and region-associated differences ( p < 0.05), including Thiomonas , Burkholderia , and Acinetobacter baumannii for tissues, and Staphylococcus xylosus , Klebsiella pneumoniae , Salmonella enterica , and Ferrovum myxofaciens for regions. The most represented bacterial orders in Al Hoceima samples were Burkholderiales , Enterobacterales , Nitrosomonadales , and Rhodocyclales . Discussion/conclusion Together, these findings highlight the spatial variability of insect–microbe association in D. opuntiae and point to candidate bacterial taxa whose distribution covaries with regional environmental conditions. This study provides baseline, descriptive microbiome data and a foundation for future functional investigations of microbial roles in host biology, which may in turn inform microbiome-aware pest management strategies across Moroccan agroecosystems.