Arid-Adapted Paradiaptomid Copepods Contribute to Mosquito Regulation

We are writing to describe the predatory potential of calanoid copepods for the regulation of mosquito larval populations in aquatic environments. Mosquito-borne diseases continue to drive unparalleled human morbidity and mortality (Ferguson 2018), and directly threaten other wildlife (George et al. 2015). This disease burden is most concentrated in Sub-Saharan Africa, where aquatic habitats exploited by mosquitoes are often temporary and, under natural conditions, characterised by arid-adapted ecological communities. These communities can be predator rich, contributing to the regulation of aquatic larval mosquito populations and therefore the adult vectors of the diseases at the landscape scale. A newly described southern African copepod species, Lovenula raynerae Suárez-Morales, Wasserman and Dalu 2015 (Paradiaptominae) (Figure 1), has been identified as an efficacious predatory agent for the natural regulation of medically important mosquito populations in temporary aquatic environments (Cuthbert et al. 2018). Evidenced from video analyses (see supplementary material video 1), the mosquito killing rates by this species even seem to be bolstered by wasteful consumption, where larval mosquitoes are killed and partially consumed, or not consumed at all. Furthermore, novel ecological assessments of other paradiaptomids in the Eastern Cape Province of South Africa (Paradiaptomus lamellatus Sars 1895) (Cuthbert et al. 2020 and ongoing work by these authors) and Central District of Botswana (Lovenula falcifera Lovén 1845) (Buxton et al. 2020b) have shown similar patterns for mosquito control. Calanoid copepods, such as paradiaptomids, have classically been thought to not consume mosquitoes and thus offer no biocontrol potential (Marten and Reid 2007). However, the predatory efficiency and extensive distribution of paradiaptomids in Africa (Rayner et al. 2001) suggests widespread contributions to mosquito control by this diaptomid subfamily. The paradiaptomids are mostly endemic to Africa and are adapted to life in temporary wetlands. As temporary wetland specialists, they produce drought-resistant eggs that rapidly hatch and develop following rainfall events, enabling predator populations to develop quickly (Wasserman et al. 2018), in turn enhancing disease vector regulation potential. However, very little ecological work has been done on this widespread group, apart from recent studies in southern Africa (see Bird et al. 2019 and references therein; Cuthbert et al. 2020). Although this recent research has focused on control of Culex spp., similar efficacies against other mosquito genera (e.g. Aedes and Anopheles) are likely, but require further investigation. Understanding ecosystem services provided by key taxonomic groups is essential for effective environmental management. We posit that the paradiaptomids provide widespread natural mosquito biocontrol services that are Letter