Mosquito Biting and Movement Rates as an Emergent Community Property and The Implications for Malarial Interventions

Abstract

Malaria, a mosquito-vectored disease, continues to be one of the most important scourges afflicting humankind. In this paper, we take a mosquito-centric approach by studying mosquito states (i.e., energy, neurological health, and toxin information state) to demonstrate how key parameters of malaria, biting and movement rates and mosquito survival, are all emergent properties of those states when considered in the context of the background community interactions. We do so as follows: First, we develop a dynamic state variable model of mosquito biting and movement decisions that maximize mosquito expected reproductive success (fitness), and then we embed those optimal policies in a Monte Carlo simulation wherein mosquitoes attempt to feed on human hosts at domiciles where insecticide-treated bednets (ITNs) and insecticidal residual wall sprays (IRSs) are used. We find that biting rates, at the domicile level, are not impacted by mosquito state but that emigration rates from domiciles are determined by an interaction between mosquito energy state, information state, and risk of predation. This means that malaria incidence, at the village level at least, may be best understood as a response of mosquitoes to their ecological community that includes nectar-bearing plants, predators, the spatial arrangement of homes, and the protection of humans in those homes.

Modelling evolutionarily stable strategies in oviposition site selection, with varying risks of predation and intraspecific competition

“…However, many studies have attempted to estimate general daily adult survival probability, denoted here by S. Daily mortality could reflect a number of environmental conditions, such as inter-pool distances (affecting flight time while searching), the effects of species that prey on adult mosquitoes, or human intervention such as insecticide spraying (Roitberg and Mangel 2010). In our simulations, we varied S between realistic extremes to cover a wide range of environments with different adult mortality (for empirical estimates, see Kiszewski et al 2004), and gave only a qualitative relationship between S and the activity-specific survival rates, S b and S g .…”

Environmental influences on mosquito foraging and integrated vector management can delay the evolution of behavioral resistance

“…This should not affect our results as we did not vary larval habitat abundance, but for a model investigating a combination of ATSB and larval source management, such detail could be relevant. Additionally, sugar feeding may be expressed more or less strongly depending on age (Foster and Takken 2004), have a different diel periodicity than blood host seeking, or depend on the extent of spatial separation between domiciles and nectariferous plants and the outside predation risk (Ma and Roitberg 2008;Roitberg and Mangel 2010). Individual-or agent-based models that track energetic state to capture state-based foraging decisions in more detail do exist (Ma and Roitberg 2008;Roitberg and Mangel 2010;Zhu et al 2015).…”

“…Additionally, sugar feeding may be expressed more or less strongly depending on age (Foster and Takken 2004), have a different diel periodicity than blood host seeking, or depend on the extent of spatial separation between domiciles and nectariferous plants and the outside predation risk (Ma and Roitberg 2008;Roitberg and Mangel 2010). Individual-or agent-based models that track energetic state to capture state-based foraging decisions in more detail do exist (Ma and Roitberg 2008;Roitberg and Mangel 2010;Zhu et al 2015). However, our simplified behavioral model captures two critical aspects of sugar-feeding behavior: (i) sugar feeding tends to occur facultatively, that is, it becomes more common as blood hosts are rarer and (ii) it affects vectorial capacity by both extending the duration of the gonotrophic cycle and lowering the biting rate on humans, and increasing mosquito survivorship (Stone and Foster 2013).…”

“…Further, we assume that all resources are well‐mixed in the environment; that mosquitoes are aware of the relative abundance of resources; and that time or energetic costs associated with entering or leaving houses are negligible. Investigating these issues would require a different type of model (e.g., Roitberg and Mangel ), and is beyond the scope of the current paper. Here, host exploitation is given by: …”

A Community-Ecology Framework for Understanding Vector and Vector-Borne Disease Dynamics

“…Three papers in this compendium (kershenbaum et al, 2010;Roitberg and mangel, 2010;Vonesh and Blaustein, 2010) consider the importance of predation risk. Early theoretical and empirical studies focused on predators' effects on prey populations via mortality from prey consumption.…”