Agricultural activities significantly affect freshwater ecosystems, primarily through recurrent contamination of surface water by a broad variety of organic pollutants (Kumar et al., 2023). Pesticides, in particular, are major contaminants of ground and surface water, harming aquatic ecosystems through spray drift, leaching, erosion, and other means (Schulz, 2004). However, the ecotoxicity studies for risk assessment involve relatively lower concentrations of pesticides, below the acute level of toxicity. Additionally, the assessment of transgenerational effects of pesticide pollutants on multiple generations of aquatic insect populations is of increasing concern among the scientific community (Coutellec and Barata, 2011; Coutellec and Barata, 2013).

The extensive and on-going use of pesticides in agriculture is a growing problem, resulting in increased resistance in mosquito vectors (Naqqash et al., 2016). Many of these vectors, such as the yellow fever mosquito Aedes aegypti (Diptera: Culicidae), transmit fatal and extremely debilitating infectious diseases including dengue, yellow fever, Zika, and chikungunya virus. Thus, agrochemicals are indirectly increasing the disease burden transmitted by mosquitoes. The immature stages of A. aegypti are spent in freshwater settings, both natural and man-made (such as ground pools, catch basins, storm drains, and discarded tyres), where they may be exposed to a range of agricultural pesticides (David et al., 2000; Nkya et al., 2013).

Because of improper application and pesticide dispersion many insecticides not only kill insect pests directly but also have a variety of sublethal effects on them (Biondi et al., 2012; Fogel et al., 2013; Guedes et al., 2016). Sublethal effects are defined as changes to the physiology and/or behaviour of insects that survive pesticide treatment at a dose that is either lethal or sublethal (De França et al., 2017). These include developmental delays or accelerations, changes in pupation and emergence rates, alterations in larval and pupal weight, fertility, egg hatching rates and sizes, and adult longevity. Several pesticides have deleterious sublethal effects that suppress pest population growth (Yin et al., 2022; Shafi et al., 2023). Contrarily, stimulatory/hormetic effects have been extensively studied and associated with plausible reasons for insect resurgence and further outbreaks due to enhanced biotic potential (Niu et al., 2024; Zhang et al., 2024).

Two commonly used insecticides, i.e., thiamethoxam and emamectin benzoate, were selected for transgenerational studies. Thiamethoxam is a common neonicotinoid insecticide used for the management of sucking insect pests in different crops (Elbert et al., 2008; Cho et al., 2011). It is an agonist that acts on the nicotinic acetylcholine receptors (nAChRs) in insects’ nervous systems (Tomizawa and Casida, 2005). Because of its broad-spectrum insecticidal activity, thiamethoxam efficiently manages a range of insect pests (Goulson, 2013; Zhang et al., 2024). Emamectin benzoate (EMB), a novel and potentially effective insecticide, paralyses insects for life by mimicking the action of the inhibitory neurotransmitter GABA. The associated GABA channel is irreversibly opened when EMB binds to the GABA receptor complex (Mashal and Obeidat, 2019). It could also activate HACls and pHCls in fall armyworm (Yin et al., 2022; Wang et al., 2025). Using the age-stage two-sex life table, we investigated the long-term effects of sublethal exposure as well as the transgenerational effects of thiamethoxam and emamectin benzoate in A. aegypti. The detoxifying enzyme activities of A. aegypti were also measured. These findings will aid in optimizing pesticide dosage and application schedules for effective chemical management of A. aegypti.