In Vitro Predation Efficiency of Ladybird Beetles as a Biocontrol Agent on Aphids Available in Bangladesh Coast

Aphids ( Aphis spp. ) are significant pests in agriculture, and the use of ladybird beetles (Coccinellidae) as biological control agents offers a sustainable alternative to chemical pesticides. However, their predation efficiency in coastal agroecosystems remains underexplored. This study evaluated the predation efficiency of three coccinellid species- Coccinella transversalis , Menochilus sexmaculatus , and Cheilomenes sanguinea against Aphis craccivora and Aphis gossypii under controlled laboratory conditions (21 ± 4°C; 67 ± 1% RH). Larvae were individually placed in Petri dishes with three replicates per species, and aphid consumption was recorded across all larval stages and adult beetles. Menochilus sexmaculatus exhibited rapid development and consumed comparable aphid numbers in a shorter period (consumed 37.7 ± 2.0 A. craccivora and 41.8 ± 2.0 A. gossypii by 4th instar of beetle on day 8), indicating high early-stage efficiency. C. sanguinea consumed fewer aphids overall (consumed 19.7 ± 1.3 A. craccivora , 18.0 ± 1.7 A. gossypii by 4th instar of beetle on day 15), but showed consistent feeding across stages, suggesting potential for sustained control. C. transversalis demonstrated the highest total consumption (consumed 55.0 ± 18.5 A. craccivora , 46.0 ± 1.7 A. gossypii by 4th instar of beetle on days 13–14), supporting its role as a long-term biocontrol agent. These results highlight the species-specific predation efficiencies of coccinellids and support their integration into ecologically based pest management programs. Field validation is recommended to assess performance under variable coastal conditions.