Morphometric and molecular insights into Bactrocera dorsalis (Hendel, 1912) (Diptera: Tephritidae) infestation on Ziziphus mauritiana Lamk. (Indian Jujube)

TL;DR

This study combines physical and genetic analysis to understand the infestation patterns of fruit flies on Indian jujube crops.

Contribution

The integration of morphometric and molecular data offers a novel framework for distinguishing B. dorsalis populations.

Findings

Morphometric measurements revealed sexual dimorphism and population variability in B. dorsalis.

Molecular analysis using COI gene sequences showed phylogenetic proximity to B. invadens and B. kandiensis.

Principal component analysis highlighted distinct trait contributions between male and female populations.

Abstract

Bactrocera dorsalis (Diptera: Tephritidae), is an oriental fruit fly, commonly infesting fruit crops, especially Indian jujube (Ziziphus mauritiana) and other fruit crops in India. This study combined morphometric and molecular approaches to evaluate population variability. Eggs were creamy white, elliptical, and measured length and width of 1.30 and 0.23 mm. Mature maggots attained 7.87 and 1.94 mm, while pupae averaged 4.91 and 1.90 mm. Adults exhibited clear sexual dimorphism, with females larger (body length 6.87 mm; wing expanse 12.48 mm) than males (body length 5.74 mm; wing expanse 10.48 mm). Principal component analysis indicated that male traits such as body length and maggot size loaded strongly on the first component, while female wing and thoracic traits contributed predominantly to the second component, cumulatively explaining over 100% of the variation. Molecular characterization using COI gene sequences revealed phylogenetic clustering patterns that were consistent with the morphometric differentiation observed among populations and indicated close phylogenetic proximity of Indian populations to B. invadens and B. kandiensis. The integration of morphometric and molecular datasets thus provides a reliable framework for distinguishing populations of B. dorsalis, which is essential for accurate diagnostics, monitoring, and region-specific management strategies.

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