SEASONAL SURVEILLANCE OF MOSQUITO EGGS AND LARVAE IN VILLAGES SURROUNDING THE CHANA POWER PLANT, SONGKHLA PROVINCE, THAILAND

ABSTRACT Mosquito population dynamics in industrial-adjacent communities are driven by complex interactions between seasonality and anthropogenic habitats. This study investigated seasonal abundance, species composition, and spatial oviposition patterns of mosquito eggs and larvae surrounding the Chana Power Plant, Thailand. Ovitraps and larval surveys were conducted across 3 seasonal phases (preoutbreak, outbreak, and postoutbreak), using a census approach. Data were analyzed via chi-square tests and a 2-part Hurdle model (logistic and negative binomial regression) to account for zero inflation and overdispersion. Mosquito dynamics exhibited a decoupling of oviposition stability from larval abundance; ovitrap positivity showed no significant seasonal variation, whereas larval indices—House Index (HI), Container Index (CI), Breteau Index (BI), and Pupal Index (PI)—peaked significantly during the outbreak phase. Aedes aegypti exhibited a significant increase from preoutbreak (60.61%) to postoutbreak (86.44%); odds ratio (OR) = 4.14, 95% confidence interval (CI): 1.50–11.51, P = 0.01. Conversely, Ae. albopictus declined from a preoutbreak peak (45.45%) during the postoutbreak phase (OR = 0.34, 95% CI: 0.14–0.85, P = 0.02) . Spatial analysis revealed a significant indoor oviposition preference during the outbreak (61.49% vs. 39.18%, P < 0.001), with Ae. aegypti favoring domestic containers and Ae. albopictus preferring plant-associated habitats. Negative binomial regression indicated no significant seasonal associations for mosquito abundance of either species, although Ae. aegypti showed a borderline trend toward lower abundance postoutbreak (incident rate ratio [IRR] = 0.74, 95% CI: 0.54–1.01, P = 0.059). Mosquito-borne risks are highly seasonal and spatially heterogeneous. We recommend a dual-track vector control approach: prioritizing household-level management for Ae. aegypti and broader environmental control for Ae. albopictus , synchronized with seasonal climatic shifts.