Predation resistance does not trade off with competitive ability in early-colonizing mosquitoes

Abstract

The tradeoff between colonization and competitive ability has been proposed as a mechanism for ecological succession, and this tradeoff has been demonstrated in multiple successional communities. The tradeoff between competitive ability and predation resistance is also a widely-described phenomenon; however, this tradeoff is not usually postulated as a cause of ecological succession. Early successional species that arrive before predator colonization could be either (1) Less vulnerable to predation than their successors, by virtue of being poor competitors (direct competition-predation tradeoff); (2) Equally or more vulnerable to predation, because they normally colonize ahead of predators in succession and therefore are not evolutionarily adapted to avoid predators that they rarely encounter (no competition-predation tradeoff). To test these alternative hypotheses, we established water-filled containers in an oak-hickory forest. We allowed half of the containers to be naturally colonized by early-successional Culex mosquitoes, mid-successional Aedes mosquitoes, and the mosquito predator Toxorhynchites rutilus. In the other half of the containers we prevented Aedes colonization via systematic removal of Aedes eggs, but allowed Culex and T. rutilus to colonize. The numbers of mature Culex larvae and pupae, and later the total number of Culex, were significantly greater in containers where Aedes had been removed, which suggests that Culex are competitively suppressed by Aedes. Toxorhynchites rutilus abundance and colonization rate were unaffected by the removal of Aedes, and densities of both Culex and Aedes decreased significantly with T. rutilus abundance in both treatments. In-lab bioassays showed that Culex were significantly more vulnerable to predation by T. rutilus than were Aedes. These data are consistent with the hypothesis that Culex and Aedes demonstrate a direct colonization/competition tradeoff, and are inconsistent with the hypothesis of a direct competition/predation tradeoff.

Contributions of temporal segregation, oviposition choice, and non-additive effects of competitors to invasion success of Aedes japonicus (Diptera: Culicidae) in North America

“…Experiments at this site in June-July 2010 indicated that A. japonicus comprised >90 % of the Aedes in 19 L buckets (Murrell and Juliano 2013), whereas experiments in May–August 2011 yielded assemblages in 19 L buckets with A. japonicus and A. triseriatus co-dominant (Murrell et al 2014). Thus, the relatively low density of A. japonicus in the present field results is not surprising.…”

“…A. japonicus is competitively inferior to A. albopictus (Kesavaraju et al 2010; Armistead et al 2008a, b), and merely competitively equivalent to the North American tree hole mosquito Aedes triseriatus (Say) (Hardstone and Andreadis 2012; Alto 2011), two container-dwelling Aedes species that are often sympatric and syntopic with A. japonicus in Eastern North America. A. japonicus also does not appear to be less vulnerable than other Aedes species to the larval predator Toxorhynchites rutilus (Coquillett) (Murrell and Juliano 2013). …”

Invasion Biology ofAedes japonicus japonicus(Diptera: Culicidae)

“…restuans in containers in Connecticut after Ae. j. japonicus became established in the state, and Murrell & Juliano (71) observed negative effects of Ae. j. japonicus on Culex (primarily Cx.…”

“…j. japonicus is less susceptible to T. rutilus predation than Culex spp., which have different foraging behaviors than Aedes spp. in general (71). Therefore, it is not yet clear whether Ae.…”

Avaliação de índice de infestação de Culex quinquefasciatus e registro de reclamações de incômodo em áreas referentes aos piscinões de Santo André, SP

“…Com muito alimento e sem a regulação da cadeia ecológica de predação, a espécie tende a proliferar em elevada densidade, tornando-se uma praga urbana. Murrel & Juliano (2013) fizeram um teste em abrigos naturais controlados que seriam ocos de árvores separando grupos de larvas em dois grupos. No primeiro grupo foram colocadas larvas de Culex quinquefasciatus, Aedes aegypti e uma espécie predadora de ambas, Toxorrinchites rutilus.…”