Repellent Efficacy of Monotypic and Binary Formulations of Psidium guajava and Basella rubra Leaf Extracts Against Aedes aegypti
Year: 2026
Type: article
Abstract: Background: The reliance on synthetic mosquito repellents like DEET necessitates the exploration of safer botanical alternatives. This study evaluated the spatial repellency of Psidium guajava (guava) and Basella rubra (Malabar spinach) leaf extracts, both monotypic and binary, against adult female Aedes aegypti mosquitoes. Methods: Using a custom Excito-Repellency Test Chamber Assay, seven formulations were tested: 100% P. guajava, 100% B. rubra, three volumetric combinations (50:50, 25:75, 75:25), a 12% DEET positive control, and an untreated negative control. Fifteen non-blood-fed mosquitoes were exposed per trial, with chamber escape rates tracked over 15 minutes. Relative efficacy was analyzed using One-Way ANOVA and Tukey's HSD post-hoc test. Results: The 100% P. guajava formulation exhibited 66.67% mean repellency, performing at a level statistically comparable to DEET (86.67%, p = 0.1936). Conversely, 100% B. rubra demonstrated weak vapor-phase activity (53.33%) and fell significantly below the synthetic standard (p = 0.0249). Blending the two extracts across all tested ratios yielded a consistent 62.22% repellency rate. While this interaction was additive rather than synergistic, incorporating just 25% guava extract supplied enough volatile terpenoids to elevate B. rubra's spatial performance to a level statistically equivalent to DEET. Conclusions: P. guajava leaf extract is a highly effective standalone botanical spatial repellent. While pure B. rubra lacks the volatility required for vapor-phase deterrence, combining it with guava extract creates a stable, viable alternative formulation for vector control.
Institution: The Manila Times College of Subic
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: gold
OpenAlex ID: W7214219262