Individual and Interactive Effects of a Predator and Controphic Species on Mosquito Populations

Abstract

Species sharing the same trophic level as mosquito larvae (hereafter, controphic species) may have complex effects on mosquitoes by sharing both predators and food resources. We conducted an outdoor artificial pool experiment to assess the individual and interactive effects of a predator (Anax imperator) and controphic species (primarily Daphnia magna) on larval populations of two common mosquitoes, Culex pipiens and Culiseta longiareolata. Controphic species did not significantly affect survival to pupation of C. pipiens but did increase time to metamorphosis and reduce size at metamorphosis. Culex pipiens and D. magna, both primarily filter feeders, probably compete for food resources. Controphic species caused a small reduction (21.9%) in C. longiareolata survival, an unexpected result given that C. longiareolata larvae are thought to be primarily periphyton grazers while D. magna is a filter feeder. Controphic species did not affect C. longiareolata time to, or size at, pupation. Anax imperator reduced C. longiareolata survival to pupation (78%) and size at pupation (11.5%) while increasing development time in males only (11.3%). Anax imperator caused a smaller (32.4%), but statistically significant, reduction in the number of C. pipiens surviving to the pupal stage but did not significantly affect size at or time to pupation. The predator did not reduce controphic species densities, and controphic species did not result in increased predator growth. We predicted that controphic species, by serving as competitors, would result in fewer C. pipiens surviving to pupation in the absence of predators. In the presence of the predator, the negative competitive effect of controphic species would be attenuated by the positive effect of serving as alternative prey. Our results followed this pattern although the predator × controphic species interaction was not statistically significant (P = 0.157). Because previous studies showed that D. magna did not affect predation rates by A. imperator on C. longiareolata larvae, and because controphic species did not have a strong competitive effect, we did not predict and did not find a predator × controphic species interactive effect.

Microzooplankton Stoichiometric Plasticity Inferred from Modeling Mesocosm Experiments in the Peruvian Upwelling Region

“…In the omnivore NNPZ-o configurations we also allow top-down control, hereafter called intraguild predation, within the microzooplankton compartment (Figure 2). Intraguild predation is seen in our model as controphic species predation rather than cannibalism, since we assume that each microzooplankton compartment represents many species encompassing a range of sizes (Stav et al, 2005). We differentiate between the NNPZ-s (specialist) and NNPZ-o (omnivore) configurations by means of different microzooplankton feeding behavior represented by different prey capture coefficients (φ) to simulate variations in food preferences.…”

Predators indirectly control vector-borne disease: linking predator–prey and host–pathogen models

“…Because vector-borne pathogens are dependent on a vector species for transmission, pathogen persistence may be affected by predator -vector dynamics in addition to predator -host interactions. For example, a variety of predators consume the larvae of different diseasetransmitting mosquito species (Kumar & Hwang 2006;Floore 2007 for recent reviews), and these predators are capable of regulating mosquito populations (Chase & Knight 2003;Stav et al 2005;Juliano 2007Juliano , 2009Seng et al 2008). To date, however, there has not been a theoretical exploration of the impact of predatorvector interactions on the transmission or persistence of vector-borne pathogens.…”

Opportunistic foraging by heteropteran mosquito predators

“…The abundance of these dipteran species is known to be affected by predation by notonectids (Blaustein 1998;Eitam et al 2002;Blaustein et al 2004;Hampton 2004), copepods Rao 1999, 2003;Rao and Kumar 2002;Rey et al 2004), coleopterans (Von Kögel 1987Lundkvist et al 2003;, and larval odonates (Fincke et al 1997;Stav et al 2005). Such assemblages of multiple prey and predators in aquatic environments can be exploited for biological control using a community ecology approach (Murdoch et al 1985;Symondson et al 2002;Blaustein and Chase 2007).…”

“…Equally, the effect of the availability of alternate prey on the survival of target prey species in a community with a common predator species must be assessed. Relative size of the target and non-target prey generally affects predator preference, as exhibited by the copepods Mesocyclops thermocyclopoides (Kumar and Rao 2003), the dragonfly nymph Anax imperator (Stav et al 2005), and the dytiscid beetles Rhantus sikkimensis and R. consputus (Von Kögel 1987). The water bugs considered in the present study have differences in prey size preferences and predatory attributes with respect to their larval mosquito prey (Saha et al 2007a, b).…”