Mosquitoes are recognized as one of the deadliest organisms as they function as primary vectors for diseases that affect humans and result in millions of fatalities annually (Rasool et al., 2020; Aremu et al., 2022). They transmit a variety of pathogens, including yellow fever, Zika, chikungunya, dengue, and filariasis, and pose significant health risks in tropical and subtropical regions (WHO, 2018). Culex quinquefasciatus, a nematode, that transmits Wuchereria bancrofti, the causative organism of lymphatic filariasis, is linked to approximately 120 million infections, of which 76 million have damaged lymphatic and renal systems (Mariappan and Tyagi, 2018). Similarly, Aedes aegypti mosquitoes are also known to transmit dengue, which is rapidly becoming a global disease pandemic transmitted to humans through the bite of infected Aedes mosquitoes. They are also accountable for the transmission of yellow fever, Chikungunya, and Zika viruses (Adeleke, 2019; Kumar et al., 2023).

In order to reduce the global disease burden caused by mosquitoes, a variety of physical and chemical methods for controlling mosquito-borne diseases have been employed. However, these methods have limited effectiveness in reducing mosquito populations (Kumar et al., 2023). Integrated vector management (IVM) approaches, such as the use of long-lasting insecticide-treated nets (LLINs), indoor residual spraying (IRS), and environmental management, as well as larval source reduction, have been successful in reducing mosquito populations through targeting their behavioural attributes and destroying their larval breeding sites (WHO, 2018). Larviciding, which involves the use of bug sprays, is also a promising method for reducing mosquito populations in their breeding sites (Dambach et al., 2021). However, the widespread use of chemical methods like pyrethroids is associated with resistance challenges (Keita et al., 2021; Aremu et al., 2022). The development of resistance and the diversity of breeding habitats pose an urgent threat to the complete eradication of mosquitoes as vectors. Therefore, there is a pressing need to develop alternative methods to control vectors and combat these parasites.

Plants contain phytochemicals that have biological activity and aid in defence against pathogenic microorganisms and insects (Aremu et al., 2023). Additionally, because they are target-specific, biodegradable, and eco-friendly, plants can serve as a substitute for conventional insecticides. These insecticides have different modes of action, reducing the probability of resistance in mosquito populations (Kumar et al., 2023). Plants are a rich source of various biologically active compounds that are effective against mosquito vectors due to their diverse modes of action. The bioactive compounds in plants may have heightened biological activity due to the synergistic effects of active or individual compounds (Tousif et al., 2022). Unlike conventional insecticides with single-component bioactive compounds, plant-derived insecticides contain multiple chemical compounds that act in unison on both physiological and behavioural processes through several mechanisms of action that counter the development of resistance (Kumar et al., 2023). Hence, a more effective and sustainable approach to managing Ae. aegypti and Cx. quinquefasciatus would involve the utilization of bioinsecticides through unconventional methods.

Guava (Psidium guajava L.) is an important member of the Myrtaceae family and is widely cultivated as a fruit tree throughout the world, particularly in tropical and subtropical regions (Kartini and Sofia, 2022). Due to its high nutritional, health, and pharmacological values, guava has been a crucial tropical fruit for several decades and has been reported to have multiple beneficial pharmacological effects, such as those on diabetes, cardiovascular disease, and cancer (Suwanwong and Boonpangrak, 2021). Its adaptability to different environments is a key factor contributing to its widespread cultivation around the world. Studies using High Performance Liquid Chromatography (HPLC) and GCMS analyses of the phytochemicals have identified the presence of flavonoids, flavanols, proanthocyanidins, dihydrochalcones and anthocyanidins, benzophenones, tannins, saponins, polyphenols, steroids, terpenoids, triterpenoids, and glycosides (Tousif et al., 2022; Kumar et al., 2023). These phytoconstituents possess larvicidal properties and can be used to control mosquito populations both in the laboratory and in the field (Muema et al., 2016; Arunthirumeni et al., 2023). Furthermore, the type of solvent used in the extraction plays a significant role in determining the characteristics and biological activities of these phytochemicals (Aremu et al., 2022).

Biological control strategies focused on immature mosquito stages may impact vector competence. Silva et al. (2021) and have both described the Psidium taxa to have great ecological, economic and medicinal relevance due to their essential oils chemical diversity and biological potential. Mendes et al. (2023) have also reported the inclusion of complexes of 2-hydroxypropyl-β-cyclodextrin with bioactive compounds in P. guajava in control of Ae. aegypti. There is evidence that using bioactive substances to alter mosquito habitat factors can drastically lower mosquito populations and have an adverse effect on the vector competence and life history attributes of adult mosquitoes (Muema et al., 2016; Alvarez et al., 2016). As a result, targeting immature mosquito stages is a viable approach for eliminating vector-borne diseases (Rawal, 2019; Kendie, 2020). Given P. guajava's significant medicinal importance and larvicidal potential, the present study aimed to evaluate the efficacy of its leaf extract using methanol, ethyl acetate, and aqueous solvents, with the possibility of identifying the solvent with the preferred larvicidal attributes. Additionally, phytochemical characterization analysis was conducted with GCMS to identify potential larvicidal compounds from each solvent fraction for the development of larvicidal products in the future.