Journal of Advances in Biology & Biotechnology

The papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae), is a polyphagous invasive pest whose population growth is strongly influenced by host-plant suitability. Life-table and age-specific fecundity studies were conducted during 2020–21 and 2021–22 to compare the demographic performance of P. marginatus on papaya (Carica papaya), potato sprouts (Solanum tuberosum) and hibiscus (Hibiscus rosa-sinensis). Daily survivorship (l_x) and age-specific fecundity (m_x) were recorded and used to estimate major population parameters. Oviposition generally extended over eight days, and peak fecundity occurred consistently around day 20 irrespective of host. Papaya supported the greatest reproductive potential, recording gross reproductive rates (GRR) of 353.58 and 335.12 and net reproductive rates (R₀) of 140.07 and 125.11 females female⁻¹ during 2020–21 and 2021–22, respectively. Corresponding R₀ values were 121.64 and 116.67 on potato sprouts and 112.95 and 102.07 on hibiscus. Pooled over the two years, R₀ was highest on papaya (132.59), followed by potato sprouts (119.16) and hibiscus (107.51). Approximate generation time varied little among hosts, averaging 19.27, 19.20 and 19.11 days on papaya, potato sprouts and hibiscus, respectively. Recalculation of the demographic parameters yielded intrinsic rates of increase (r_m) of approximately 0.254, 0.249 and 0.245 female⁻¹ day⁻¹ on papaya, potato sprouts and hibiscus, respectively. The results demonstrate that all three hosts can sustain multiplication of P. marginatus, although papaya provides comparatively favourable conditions for population increase. The findings have implications for pest surveillance, maintenance of laboratory cultures and timing of management interventions.