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

• Published in: Oecologia Vol. 173; no. 3; pp. 1033 - 1042
• Main Authors: Murrell, Ebony G., Juliano, Steven A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer 01-11-2013; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Aedes; Analysis of Variance; Animal and plant ecology; Animal Distribution - physiology; Animal, plant and microbial ecology; Animals; Aquatic insects; Bioassays; Biological and medical sciences; Biomedical and Life Sciences; Colonization; COMMUNITY ECOLOGY; Community ecology - Original research; Competition; Competitive Behavior - physiology; Containers; Culex; Culicidae - physiology; Ecological competition; Ecological succession; Ecology; Food Chain; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Hydrology/Water Resources; Insect larvae; Larvae; Larval development; Life Sciences; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Missouri; Models, Biological; Mosquitoes; Mosquitos; Plant Sciences; Plant succession; Predation; Predation (Biology); Predators; Species; Species Specificity; Time Factors; Toxorhynchites rutilus; Tradeoffs; Trees; Vectors. Intermediate hosts; Missouri; Mosquitoes; Succession; Competition–predation tradeoff; Culex; Colonization–competition tradeoff; Competition; Insecta; Parasite; Colonization-competition tradeoff; Aedes; Competitive ability; Sensitivity resistance; Arthropoda; Culicidae; Ectoparasite; Predation; Competition-predation tradeoff; Invertebrata; Vector; Diptera; Colonization
• ISSN: 0029-8549; 1432-1939
• DOI: 10.1007/s00442-013-2674-z

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); or (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-laboratory 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.