Outbreak of Hyposidra talaca Walker (Lepidoptera: Geometridae) as a new sporadic pest of mango in northern India: Insights from morphological, molecular, and ecological studies

The outbreak of the black inch worm, Hyposidra talaca Walker (Lepidoptera: Geometridae), traditionally a pest of tea plantations, as a significant threat to mango cultivation in the northern India, was investigated at ICAR-Central Institute for Subtropical Horticulture, Lucknow, India during 2023-24. Field surveys in farmers’ fields at Mallihabad, Mall, Unnao, Sandila and Itaunja revealed that H. talaca caterpillars feed on mango inflorescences (5–10%), pea size fruits (40–50%), developing fruits (30%) and foliage (15–20%), causing severe defoliation and fruit drop. Morphological and molecular characterization, including COI gene sequencing (GenBank: PV037431), confirmed the identity of pest, showing 99.79% similarity with tea-associated isolates. Phylogenetic analysis confirmed its close relationship with conspecific populations, suggesting recent host adaptation. Seasonal incidence peaked during early summer i.e. , 21st and 24th standard meteorological weeks, correlating positively with maximum temperature (r = 0.23*) and evaporation rate (r = 0.32**). The bionomics of H. talaca on mango ( cv. Dusheri) revealed a 22.28 ± 0.42 days larval period and high fecundity (458.76 ± 70.5 eggs/female), indicating outbreak potential. A total of four biological agents, including two predators and two parasitoids associated with H. talaca , were identified. Among these, Cotesia ruficrus (Haliday) and Eocanthecona furcellata (Wolff) are amenable to mass production. This study provides the first evidence of H. talaca infesting mango in India, highlighting its ecological plasticity and climate-driven host shift. These findings emphasize the need for vigilant monitoring and sustainable pest management strategies to protect mango, a vital economic crop in India.