Spatial Distribution Modeling of Stegomyia aegypti (Diptera: Culicidae) under Current and Future Climate Scenarios in Okara City, Punjab, Pakistan

Saliha Asif; Maryam  Riasat; Muhammad  Naeem

doi:10.65139/v7wpzt72

Authors

Saliha Asif Department of Zoology, Riphah International University, Faisalabad Campus, Pakistan Author
Maryam Riasat Department of Zoology, Riphah International University, Faisalabad Campus, Pakistan Author
Muhammad Naeem Department of Zoology, Riphah International University, Faisalabad Campus, Pakistan Author

DOI:

https://doi.org/10.65139/v7wpzt72

Keywords:

Stegomyia aegypti, dengue vector, species distribution modeling, MaxEnt, climate change, SSP scenarios

Abstract

Dengue fever is a rapidly spreading vector-borne disease in Pakistan, with Stegomyia aegypti (formerly Aedes aegypti) as its primary mosquito vector. Okara City, located in Punjab Province, has experienced recurring dengue outbreaks, yet systematic spatial risk mapping of the vector remains limited. This study used a MaxEnt-based species distribution modeling (SDM) approach to map the current habitat suitability of St. aegypti in Okara City and to project changes in suitability under two future climate scenarios, SSP245 (moderate emissions) and SSP585 (high emissions), for the years 2050 and 2070. Mosquito occurrence data were collected from 12 geo-referenced sites within the urban and peri-urban boundary of Okara City (132.56 km²). Environmental predictors included the urban built-up index, distance to standing water, mean annual temperature, NDVI, annual rainfall, and distance to the road. The model showed excellent discriminatory performance. Under current conditions, 47.38 km² (35.7%) of the city boundary was classified as high-suitability habitat. Future projections indicated a progressive increase in high-suitability area under both SSP pathways, reaching up to 95.17 km² (71.8%) under SSP585 by 2050. Urban intensity and proximity to standing water were identified as the strongest predictors of vector occurrence. These findings provide spatially explicit risk information for dengue surveillance and vector control prioritization in Okara City.

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