Mosquito Species Richness, Composition, and Abundance along Habitat-Climate-Elevation Gradients in the Northern Colorado Front Range

Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO 80523, USA.
Journal of Medical Entomology (Impact Factor: 1.95). 08/2008; 45(4):800-11. DOI: 10.1603/0022-2585(2008)45[800:MSRCAA]2.0.CO;2
Source: PubMed


We exploited elevation gradients (1,500-2,400 m) ranging from plains to montane areas along the Poudre River and Big Thompson River in the northern Colorado Front Range to determine how mosquito species richness, composition, and abundance change along natural habitat-climate-elevation gradients. Mosquito collections in 26 sites in 2006 by using CO2-baited CDC light traps yielded a total of 7,136 identifiable mosquitoes of 27 species. Commonly collected species included Aedes vexans (Meigen) (n = 4,722), Culex tarsalis Coquillett (n = 825), Ochlerotatus increpitus (Dyar) (n = 546), Ochlerotatus trivittatus (Coquillett) (n = 303), Aedes cinereus Meigen (n = 280), Ochlerotatus melanimon (Dyar) (n = 146), Ochlerotatus dorsalis (Meigen) (n = 67), Culiseta inornata (Williston) (n = 52), Ochlerotatus pullatus (Coquillett) (n = 38), Ochlerotatus spencerii idahoensis (Theobald) (n = 37), and Culex pipiens L. (n = 29). Species richness was highest in plains habitats at elevations below 1,600 m. Numerous species were found exclusively or predominantly at low elevations below 1,700 m [Anopheles earlei Vargas, Anophelesfreeborni Aitken, Coquilletidia perturbans (Walker), Culex erythrothorax (Dyar), Cx. pipiens, Culex territans Walker, Oc. dorsalis, Ochlerotatus hendersoni (Cockerell), Oc. melanimon, and Oc. trivittatus], whereas others occurred predominantly at high elevations above 2,300 m [Ae. cinereus, Culiseta incidens (Thomson), Culiseta morsitans (Theoblad), Ochlerotatus cataphylla (Dyar), Ochlerotatus intrudens (Dyar), Oc. pullatus, and Ochlerotatus punctor (Kirby)]. Ae. vexans and Cx. tarsalis were abundant in the plains (< 1,600 m; mean June-August temperature > 19.5 degrees C), occurred at low abundances in foothills and low montane areas (1,610-1,730 m; 18.0-19.5 degrees C), and they were collected only sporadically in montane areas above 1,750 m (mean June-August temperature < 17.5 degrees C). These findings suggest that future climate warming may lead to shifts in distribution patterns of West Nile virus vectors (e.g., Cx. tarsalis) toward higher elevations in Colorado.

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    • "ighth , it is useful to monitor for the presence of mosquitoes and horse flies at higher elevations . Some species of mosquitoes and horse flies occur exclusively at high elevations . Mosquitoes and horse flies transmit several problematic diseases , such as WNV and anaplasmosis , and producers should be wary of outbreaks ( Clark and Hibler 1973 , Eisen et al . 2008 ) . These outbreaks may be anticipated in relation to the driving climate and weather variables , primarily warmer temperatures , higher precipitation years , and stagnant water . Finally , do not assume that high - elevation grazing areas provide an impenetrable buffer against all livestock parasites . Although high - ele - vation graz"
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    ABSTRACT: Livestock parasitism on high-elevation rangeland (>1,800 m (6,000’)) may not be as well documented as parasitism is at lower elevations because producers assume elevation limits parasite persistence and exposure of livestock to parasites. Certain parasites, such as horn flies, Haematobia irritans (L.) (Diptera: Muscidae), and biting midges, Culicoides spp. (Diptera: Ceratopogonidae), a vector of bluetongue virus, are restricted to lower elevations. However, some parasites are endemic to high elevations, such as the Rocky Mountain wood tick, Dermacentor andersoni (Stiles) (Acari: Ixodidae), a vector of many diseases. Multiple horse fly and mosquito species persist at various elevation gradients, with some having preference for lower or higher elevations. For example, the horse fly, Hybomitra laticornis (Hine) (Diptera: Tabanidae), occurred from 1,700-3,035 m (5,577’-9,957’), Hybomitra phaenops (Osten Sacken) (Diptera: Tabanidae) only occurred above 2,499 m (8,198’), and the western horse fly, Tabanus punctifer (Osten Sacken) (Diptera: Tabanidae), only occurred below 2,250 m (7,381’). This variable elevation range is also expressed by several mosquito species, with six of 12 known mosquito species that transmit West Nile virus at or above 1,750 m (5,740’). Furthermore, gastrointestinal roundworms can survive > 1 yr at high elevations, use larvae inhibition to survive winter, and lungworm infection may increase with elevation. Evidence suggests changing weather patterns, climate variability, and animal movements could shift some parasites and diseases into higher elevations, such as mosquitoes and biting midges. Moving livestock to high-elevation ranges may also increase the opportunity for livestock-wildlife interactions, parasite and disease transmission, and exposure. Producers should develop high-elevation integrated pest management strategies, such as delaying or avoiding parasite treatment to optimize efficacy and reduce input costs, monitoring closely during wet years and periods of livestock-wildlife interactions, using elevation to avoid certain parasites, and not assuming that elevation is capable of preventing livestock parasitism.
    Full-text · Article · Mar 2015
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    • "Both Cx. tarsalis and Cx. pipiens have been found to be more abundant in the riparian regions of the eastern Colorado plains than in the riparian regions of the foothills and higher elevations of the Rocky Mountains (Eisen et al., 2008; Barker et al., 2009). Thus, the geographic distribution of Culex vector abundance is consistent with higher WNV transmission risk in eastern Colorado (Winters et al., 2008). "

    Full-text · Chapter · Sep 2011
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    • "However, despite these numerous investigations, the ecology of entire mosquito assemblages, as opposed to single species , remains poorly studied. Studies focused on relations between mosquito assemblages and environmental factors are mainly descriptive and consider only single environmental factors(e.g.,wetlandtypeÐSchäferetal.2008;altitudeÐ Eisen et al. 2008). However, two of the previous studies employed multivariate analyses of mosquito larvae assemblages in relation to environmental factors characterizing surface-water larval habitats (Nilsson and Svensson 1995, Alfonzo et al. 2005), and two studies were devoted to effects of landscape variables on adult mosquito assemblages (Schäfer et al., 2004, 2006). "
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    ABSTRACT: Despite numerous ecological studies with mosquitoes, it remains unclear what environmental factors are the most important determinants of structure, species richness, and abundance of mosquito assemblages. In the current study, we investigated relations between these characteristics of mosquito larvae assemblages and environmental factors in a large set of different habitats. Particular objectives were (1) to rank the factors regarding their explanatory power, and (2) to quantify the contribution of major sets of factors such as habitat spatial/hydrological (H), water physico-chemical (W), and aquatic vegetation characteristics (V). Variance partitioning and forward selection based on ordinations and multiple regressions were applied to the data set on 79 water-bodies in southwestern Siberia covering a wide gradient of environmental characteristics and diverse mosquito assemblages. The results showed that richness and abundance inter-correlated poorly (r2 = 0.21), and assemblage structure, richness, and abundance depended on different sets of predictors. Explanatory importance of the three sets of environmental factors differed among the three assemblage variables: H, W, and V had equal importance for assemblage structure, while richness and abundance depended on H and V more than on W. The study showed that contradiction between the aims of conservation (support biodiversity) and mosquito control (reduce mosquito abundance) can be avoided, as relevant environmental factors can be used to define habitats with high richness and low abundance (i.e., high conservation value and low nuisance and disease transmission risk) for conservation activities, and conversely for control measures.
    Full-text · Article · Mar 2010 · Journal of Medical Entomology
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