Implications of guppy (Poecilia reticulata) life‐history phenotype for mosquito control

Abstract

Guppies (Poecilia reticulata) are frequently introduced to both natural and artificial water bodies as a mosquito control. Laboratory studies have demonstrated that guppies can consume large numbers of larval mosquitoes. Our study investigates how intraspecific variability in guppy phenotype affects their importance as a mosquito biocontrol and how habitat conditions (natural ponds vs. water storage containers) may influence insect biomass and guppy feeding. Using a blocked experimental design, we established stream‐side mesocosm ponds with half receiving gravel substrate to simulate pond‐bottom habitat. To provide realistic diet choices and insect abundances, we allowed the mesocosms to colonize naturally with aquatic insect larvae for 1 month before introducing guppies. We tested two distinct guppy phenotypes (from high‐ and low‐predation streams) alongside fish‐free controls. After 1 month, we measured insect biomass in the mesocosms and examined guppy gut contents to document direct predation. While overall insect biomass was not significantly different across the three fish treatments, we observed a significant reduction in mosquito biomass in fish treatments compared to fish‐free controls, as well as intraspecific differences in feeding. Overall insect biomass was significantly higher in mesocosms without gravel, while habitat condition had no effect on mosquito biomass. As guppy phenotype responds to changes in their environments, it is an important consideration for biocontrol policy to anticipate potential ecosystem effects. We close by relating our findings to other studies and by discussing the implications and potential risks of using guppies to control mosquitoes.

Biodiversity and ecosystem risks arising from using guppies to control mosquitoes

“…Faecal analysis from wild guppies suggests a much lower average mosquito feeding rate than in laboratory experiments [13,16]. In Trinidad, we have observed extensive feeding on mosquitoes when guppies are housed in planters full of stagnant water [17], but not in moving waters or in natural populations [18,19]. Guppies also eat fewer mosquitoes in polluted water, probably because they have a greater diversity of food choices [20].…”

Altered visual environment affects a tropical freshwater fish assemblage through impacts on predator–prey interactions

“…Torres-Dowdall et al 2012;Kranz et al 2018;Ehlman, Martinez & Sih 2018) Gordon et al 2015). These abilities, as well as effective dispersal strategies common in Poecilidae, may also contribute to the guppy's impact as an invasive species in many places outside its native range (El-Sabaawi et al 2016;Warbanski et al 2017). Ultimately, linking the short-term effects of anthropogenic change to long-term demographic change at the community scale will allow for greater power in predicting which species are likely to not only appropriately behaviourally respond to environmental change but also persist at high abundance in spite of (or because of) it.…”

“…flying insects concentrating around light), or disorient prey (Fleming & Bateman 2018). These abilities, as well as effective dispersal strategies common in Poecilidae, may also contribute to the guppy's impact as an invasive species in many places outside its native range (El-Sabaawi et al 2016;Warbanski et al 2017). reduced snowpack making hares The reported resilience of guppy populations in response to a major anthropogenic disturbance in Trinidadian streams has implications worldwide.…”

Toxicity of Terahertz-Based Functional Mineral Water (Plant-Derived) to Immature Stages of Mosquito Vectors

“…Naturally occurring agents such as predators [ 5 ], herbal extracts [ 6 ] or microbial mosquitocides [ 7 ] have become increasingly attractive and profitable alternatives as they are recognized as green pest-control agents, possibly with novel modes of action. For example, guppies ( Poecilia reticulata ) are frequently introduced to both natural and artificial water bodies as biological control agents for mosquitoes [ 8 , 9 ]. Another example is functional water produced from plant-derived minerals, or acid electrolyzed water, which has proven useful in agricultural pest control and medicinal disinfection [ 10 , 11 , 12 , 13 ].…”