Species composition of male Bactrocera spp. captured by methyl eugenol traps in Karawang Mango Orchards, Indonesia

ABSTRACT

Fruit flies (Diptera: Tephritidae) are major pests reducing mango (Mangifera indica L.) productivity in Indonesia. Information on fruit fly community structure in Karawang Regency remains limited, and the ecological implications of male-biased sampling using methyl eugenol have not been previously evaluated. This study aimed to analyze the species composition, diversity, and dominance structure of fruit flies in a mango orchard in Ciampel District using methyl eugenol traps, providing the first ecological baseline for Bactrocera communities in Karawang. Sampling was conducted from August to December 2025 using five traps during four sampling periods at two-week intervals. Captured specimens were identified morphologically using standard taxonomic keys. A total of 1,469 individuals representing six species were recorded: Bactrocera dorsalis, B. occipitalis, B. zonata, B. kandiensis, B. correcta, and B. umbrosa. Bactrocera dorsalis was the dominant species (57.99%). The Shannon–Wiener diversity index (H′ = 1.28) indicated moderate diversity, whereas the Simpson dominance index (C = 0.38) indicated low dominance. The fruit fly community was relatively stable but strongly dominated by B. dorsalis, reflecting host availability within the semi-polyculture orchard. Nevertheless, because methyl eugenol selectively attracts male individuals, the observed community structure should be interpreted as a male-biased representation of the fruit fly assemblage. This study provides the first ecological baseline of male-attracted Bactrocera communities in Karawang and highlights the importance of considering attractant-induced sampling bias in ecological assessments. The findings support the development of location-specific integrated pest management strategies, including optimizing the Male Annihilation Technique (MAT) and conserving natural enemies.