Larval Development Varies Across Pond Age and Larval Density in Cope's Gray Treefrogs, Hyla chrysoscelis

Abstract Background Malaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated. Methods This study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder and slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite. Results Overall, mosquito emergence, duration of development and adult phenotypic quality were significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. Conclusions These results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmentally friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae (s.l.) mosquito-rearing programmes. Graphic abstract

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Colonization patterns and life-history dynamics of Culex mosquitoes in artificial ponds of different character

Canadian Journal of Zoology ◽

10.1139/z93-078 ◽

1993 ◽

Vol 71 (3) ◽

pp. 568-578 ◽

Cited By ~ 4

Author(s):

D. Dudley Williams ◽

Annette Tavares-Cromar ◽

Donn J. Kushner ◽

John R. Coleman

Keyword(s):

Life History ◽

Dissolved Oxygen ◽

Water Temperature ◽

Larval Development ◽

Development Time ◽

Larval Density ◽

Strong Relationship ◽

Terrestrial Vegetation ◽

Widespread Species ◽

Artificial Ponds

The relationship between the biology and habitat of larval mosquitoes was studied in a series of artificial ponds of differing characteristics established across a terrestrial vegetation gradient from open fields to deep woods. The ponds were uniformly colonized by two widespread species of Culex, both characteristic of small bodies of water, including artificial, "container" habitats. First-instar larvae of Culex restuans were found within 2 days of filling the ponds with water and four or five generations were produced from May until the end of September. One very long generation occurred in July, which corresponded to maximum larval densities. Overall, there was a strong relationship between larval development time of C. restuans and larval density. A few larvae of Culex pipiens pipiens occurred sporadically throughout the summer, but numbers did not increase until C. restuans populations began to wane in late July. Thereafter two, or possibly three, generations were produced into the autumn. The patterns of colonization, synchrony of life history, and growth of these two species were remarkably consistent amongst the ponds, despite considerable variation in both their physical and biological environments (e.g., over the 2 years of study, conductivity ranged from 20 to 890 μS, pH from 6.4 to 10.7, dissolved oxygen from 0 to 13.5 ppm, and water temperature from 5 to 29.8 °C). Density of C. restuans was related to water temperature and pH at the "open" site and to water temperature, dissolved oxygen, percent algae, and percent detritus at the "edge of the woods" site. At the "deep woods" site, larval numbers were related to temperature, pH, conductivity, and dissolved oxygen. At both the edge and deep wood sites, larval development time of C. restuans increased with mean water temperature to 20 °C. Above this temperature, larval development time tended to decrease.

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Auditory object formation in Cope’s gray treefrogs (Hyla chrysoscelis)

The Journal of the Acoustical Society of America ◽

10.1121/1.4805942 ◽

2013 ◽

Vol 133 (5) ◽

pp. 3407-3407

Author(s):

Mark A. Bee ◽

Katrina M. Schrode

Keyword(s):

Hyla Chrysoscelis ◽

Auditory Object ◽

Gray Treefrogs

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Do female frogs exploit inadvertent social information to locate breeding aggregations?

Canadian Journal of Zoology ◽

10.1139/z07-074 ◽

2007 ◽

Vol 85 (9) ◽

pp. 921-932 ◽

Cited By ~ 44

Author(s):

E.M. Swanson ◽

S.M. Tekmen ◽

M.A. Bee

Keyword(s):

Social Information ◽

Hyla Chrysoscelis ◽

Timing Of Breeding ◽

Sensory Cues ◽

Bufo Americanus ◽

Long Distance ◽

Advertisement Calls ◽

Inadvertent Social Information ◽

Gray Treefrogs ◽

Breeding Seasons

The advertisement calls of male anurans (frogs and toads) are loud and conspicuous signals, and the sound generated by breeding aggregations of males propagates over long distances. As a by-product of communication within an aggregation, the sounds of a frog chorus constitute a form of inadvertent social information that provides potential long-distance cues about the location and timing of breeding. We investigated whether female American toads ( Bufo americanus Holbrook, 1836) and Cope’s gray treefrogs ( Hyla chrysoscelis Cope, 1880) use the sounds of a chorus to locate breeding aggregations in the absence of other sensory cues. Females of both species approached speakers broadcasting recordings of a chorus made from distances of 0, 20, and 40 m, but not from distances of 80 and 160 m. Female toads also exhibited phonotaxis to a completely artificial chorus sound, but female gray treefrogs did not. We found little evidence to suggest that female American toads and Cope’s gray treefrogs differed substantially in their responses to natural chorus sounds despite potential differences in the predictability and duration of breeding seasons in these two species. Our results suggest that the inadvertent social information of a chorus could be used over short distances to locate breeding aggregations.

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Absence of Cold Acclimation Response in Gray Treefrogs, Hyla chrysoscelis and Hyla versicolor

Journal of Herpetology ◽

10.2307/1565311 ◽

1998 ◽

Vol 32 (2) ◽

pp. 283 ◽

Cited By ~ 3

Author(s):

Richard L. Lukose ◽

Howard K. Reinert

Keyword(s):

Cold Acclimation ◽

Hyla Versicolor ◽

Hyla Chrysoscelis ◽

Acclimation Response ◽

Gray Treefrogs

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Improvement of water quality for mass anopheline rearing: Evaluation of the impact of ammonia-capturing zeolite on larval development and adult phenotypic quality

10.21203/rs.3.rs-96289/v2 ◽

2021 ◽

Author(s):

Nwamaka Oluchukwu Akpodiete ◽

Frederic Tripet

Keyword(s):

Water Quality ◽

Larval Development ◽

Larval Density ◽

Malaria Vector Control ◽

Larval Rearing ◽

Emergence Success ◽

Phenotypic Quality ◽

Rearing Density ◽

Daily Water ◽

The Impact

Abstract BackgroundMalaria vector control approaches that rely on mosquito releases such as the sterile insect technique (SIT) and suppression or replacement strategies relying on genetically modified mosquitoes (GMM) depend on effective mass production of Anopheles mosquitoes. Anophelines typically require relatively clean larval rearing water, and water management techniques that minimise toxic ammonia are key to achieving optimal rearing conditions in small and large rearing facilities. Zeolites are extensively used in closed-system fish aquaculture to improve water quality and reduce water consumption, thanks to their selective adsorption of ammonia and toxic heavy metals. The many advantages of zeolites include low cost, abundance in many parts of the world and environmental friendliness. However, so far, their potential benefit for mosquito rearing has not been evaluated.MethodsThis study evaluated the independent effects of zeolite and daily water changes (to simulate a continuous flow system) on the rearing of An. coluzzii under two feed regimes (powder or slurry feed) and larval densities (200 and 400 larvae per tray). The duration of larval development, adult emergence success and phenotypic quality (body size) were recorded to assess the impact of water treatments on mosquito numbers, phenotypic quality and identification of optimal feeding regimes and larval density for the use of zeolite.ResultsOverall, mosquito emergence, duration of development and adult phenotypic quality was significantly better in treatments with daily water changes. In treatments without daily water changes, zeolite significantly improved water quality at the lower larval rearing density, resulting in higher mosquito emergence and shorter development time. At the lower larval rearing density, the adult phenotypic quality did not significantly differ between zeolite treatment without water changes and those with daily changes. ConclusionsThese results suggest that treating rearing water with zeolite can improve mosquito production in smaller facilities. Zeolite could also offer cost-effective and environmental-friendly solutions for water recycling management systems in larger production facilities. Further studies are needed to optimise and assess the costs and benefits of such applications to Anopheles gambiae s.l. mosquito rearing programmes.

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