Prospection of plant-based bio-insecticides for mosquito vector control in Tanzania: A comprehensive review

Mosquito-borne diseases, including malaria, dengue, chikungunya, zika, and lymphatic filariasis, pose significant public health challenges in Tanzania. Current vector control strategies largely depend on synthetic insecticides, but the emergence of insecticide resistance, environmental persistence, and non-target toxicity necessitates alternative, eco-friendly solutions. Plant-based bioinsecticides are gaining attention due to their biodegradability, low mammalian toxicity, and complex phytochemical profiles that hinder resistance development. This systematic review synthesizes 41 studies conducted in Tanzania up to November 2025, evaluating indigenous plant species for insecticidal and repellency activities against mosquito vectors. A total of 74 plant species from 22 families were identified across 13 Tanzanian regions, with 46 assessed for insecticidal activity. Leaves were the most utilized plant part, while sequential solvent extraction and essential oil isolation via steam distillation and hydro-distillation were the predominant extraction techniques. Larvicidal assays dominated, with 58% of tested extracts exhibiting high potency (LC₅₀ < 100 μg/mL). Plant species with high larvicidal activity included Commiphora merkeri , Dioscorea sansibarensis , Tephrosia vogelii , Uvariodendron pycnophyllum , Harrisonia abyssinica , Annona squamosa , Annona senegalensis , Annona muricata , and Neorautanenia mitis . Highly promising species for adulticidal activity and repellency were Warburgia ugandensis , Neorautanenia mitis , Tessmannia densiflora , Chenopodium ambrosioides , Ocimum spp., Syzygium aromaticum , and Cinnamomum verum . Despite encouraging findings, most studies remain laboratory-based, emphasizing the need for expanded field trials, improved extraction methods, and formulation development to harness Tanzania's rich plant biodiversity for sustainable mosquito vector control.