scholarly journals Differential effects of conspecific and heterospecific density on the development of Aedes aegypti and Aedes albopictus larvae

2018 ◽  
Author(s):  
Robert S Paton ◽  
Katherine Heath ◽  
Anthony J Wilson ◽  
Michael B Bonsall
Keyword(s):  
Aedes Aegypti ◽  
Interspecific Competition ◽  
Resource Availability ◽  
Larval Density ◽  
Single Species ◽  
List Type ◽  
Contest Competition ◽  
Species Competition ◽  
Demographic Stochasticity ◽  
Successful Development

AbstractBetween-species competition shapes the distribution and abundance of populations. Aedes aegypti and Ae. albopictus are vectors of pathogens such as dengue and are known to compete at the larval stage.The outcome of this inter-species competition has been found to be context dependent, with the strength and direction changing with resource availability and type. We were motivated by this uncertainty, and aimed to elucidate the magnitude and mechanism of competition.We manipulated the larval density of mixed and single species cohorts of larvae, measuring the effects on survivorship and development time. Unlike other related studies, we adjusted the feeding regime so that the per-capita resource availability was kept constant across all density treatments, at a level sufficient for successful development. This ensured that each larvae at least had the opportunity to gain the requisite resources for pupation.Our analysis found that Ae. aegypti suffered notably less mortality due to intra- and interspecific competition. For both species, intra- and interspecific competition led to the survival of faster developing individuals, with the exception that slower developing Ae. albopictus larvae survived when exposed a combination of both high con- and heterospecific densities.These results show that the competition between Ae. aegypti and Ae. albopictus can still occur even when resources are theoretically adequate for development. This suggests that larvae can alter resource seeking and consumption parameters when exposed to high densities of conspecifics and heterospecifics, leading to contest competition. Evidence for resource-independent mechanisms of competition such as crowding are also found, as is evidence for the importance of demographic stochasticity in population processes.

Larval Competition Between the Introduced Vector of Dengue Fever in Australia, Aedes-Aegypti (L), and a Native Container-Breeding Mosquito, Aedes-Notoscriptus (Skuse) (Diptera, Culicidae)

1986 ◽  
Vol 34 (4) ◽  
pp. 527 ◽  
Author(s):  
RC Russell
Keyword(s):  
Aedes Aegypti ◽  
Competitive Advantage ◽  
Interspecific Competition ◽  
New South ◽  
Larval Density ◽  
Larval Survival ◽  
South Wales ◽  
Survival And Development ◽  
Two Temperatures ◽  
Laboratory Investigations

The introduced vector of dengue, Aedes aegypti, has disappeared from New South Wales at the same time as the indigenous Ae. notoscriptus has increasingly intruded into the domestic environment. Laboratory investigations of larval survival and development rates for both species, alone and in various combinations, at two temperatures under varying conditions of density and food, were conducted to test the hypothesis that the latter species had a competitive advantage. For both species, in intra- and interspecific competition, survival declined markedly, and development rate increased considerably, with increasing density and decreasing food in intra- and interspecific competition. Decrease in food supply had relatively greater effect than increase in larval density, although combining both had the greatest effects. Although the native Ae. notoscriptus had a marginal advantage over the introduced Ae. aegypti at 22�C, the situation was reversed at 28�C. Overall, however, the predominant species in mixed cultures was usually advantaged. The hypothesis was not proved, although the results indicated that Ae. notoscriptus may have a competitive advantage over Ae. aegypti in cooler areas when the former species is predominant.

scholarly journals Impacts of diurnal temperature and larval density on aquatic development of Aedes aegypti

PLoS ONE ◽  
2018 ◽  
Vol 13 (3) ◽  
pp. e0194025 ◽  
Author(s):  
Josef Zapletal ◽  
Madhav Erraguntla ◽  
Zach N. Adelman ◽  
Kevin M. Myles ◽  
Mark A. Lawley
Keyword(s):  
Aedes Aegypti ◽  
Larval Density ◽  
Diurnal Temperature

scholarly journals Mating Competitiveness of Transgenic Aedes aegypti (Diptera: Culicidae) Males Against Wild-Type Males Reared Under Simulated Field Conditions

2020 ◽  
Vol 57 (6) ◽  
pp. 1775-1781
Author(s):  
David S Kang ◽  
Joanne M Cunningham ◽  
Diane D Lovin ◽  
Dave D Chadee ◽  
David W Severson
Keyword(s):  
Aedes Aegypti ◽  
Environmental Stress ◽  
Environmental Conditions ◽  
Mating Success ◽  
Genetically Modified ◽  
Field Isolate ◽  
Larval Density ◽  
Laboratory Strain ◽  
Adult Mosquito ◽  
Male Mating

Abstract Efforts directed at genetic modification of mosquitoes for population control or replacement are highly dependent on the initial mating success of transgenic male mosquitoes following their release into natural populations. Adult mosquito phenotypes are influenced by the environmental conditions experienced as larvae. Semifield studies conducted to date have not taken that under consideration when testing male mating fitness, and have compared mating success of males reared under identical environmental conditions. We performed pairwise mating challenges between males from a genetically modified laboratory strain (BF2) versus males from a recent Trinidad field isolate of Aedes aegypti (L.), a major vector of multiple arboviruses. We utilized larval density and nutrition to simulate environmental stress experienced by the Trinidad males and females. Our results indicated that environmental stress during larval development negatively influenced the competitiveness and reproductive success of males from the Trinidad population when paired with optimum reared BF2 males. Small (0.027 m3) and large (0.216 m3) trials were conducted wherein stressed or optimum Trinidad males competed with optimum BF2 males for mating with stressed Trinidad females. When competing with stress reared Trinidad males, optimum reared BF2 males were predominant in matings with stress reared Trinidad females, and large proportions of these females mated with males of both strains. When competing with optimum reared Trinidad males, no difference in mating success was observed between them and BF2 males, and frequencies of multiple matings were low. Our results indicate that future mating competition studies should incorporate appropriate environmental conditions when designing mating fitness trials of genetically modified males.

Habitat use, interspecific competition and phylogenetic history shape the evolution of claw and toepad morphology in Lesser Antillean anoles

2020 ◽  
Vol 129 (3) ◽  
pp. 630-643 ◽  
Author(s):  
Michael L Yuan ◽  
Catherine Jung ◽  
Marvalee H Wake ◽  
Ian J Wang
Keyword(s):  
Interspecific Competition ◽  
Functional Traits ◽  
Functional Morphology ◽  
Biotic Interactions ◽  
Single Species ◽  
Morphometric Data ◽  
Opposite Pattern ◽  
Geometric Morphometric ◽  
Vegetation Use ◽  
Selective Forces

Abstract Ecologically functional traits are the product of several, at times opposing, selective forces. Thus, ecomorphological patterns can be disrupted locally by biotic interactions, such as competition, and may not be consistent across lineages. Here, we studied the evolution of claws and toepads in relationship to macrohabitat (vegetation), use of structural microhabitat (perch height) and congeneric competition for two distantly related Lesser Antillean anole clades: the Anolis bimaculatus and Anolis roquet series. We collected univariate and geometric morphometric data from 254 individuals across 22 species to test the hypotheses that functional morphology should covary with both vegetation and perch height and that the presence of a competitor may disrupt such covariation. Our data showed predictable associations between morphology and macrohabitat on single-species islands but not when a congeneric competitor was present. The outcomes of competition differed between series, however. In the A. bimaculatus series, species with a sympatric congener diverged in claw and toepad traits consistent with functional predictions, whereas A. roquet series anoles showed either no association between habitat and morphology or the opposite pattern. Our results demonstrated that ecomorphological patterns across macrohabitats can be disrupted by competition-driven microhabitat partitioning and that specific morphological responses to similar ecological pressures can vary between lineages.

Container Size Alters the Outcome of Interspecific Competition Between Aedes aegypti (Diptera: Culicidae) and Aedes albopictus

2018 ◽  
Vol 56 (3) ◽  
pp. 708-715 ◽  
Author(s):  
Allison T Parker ◽  
Allison M Gardner ◽  
Manuel Perez ◽  
Brian F Allan ◽  
Ephantus J Muturi
Keyword(s):  
Aedes Aegypti ◽  
Interspecific Competition ◽  
Aedes Albopictus

Resource matching across habitats is limited by competition at patch scales in an estuarine-opportunist fish

2005 ◽  
Vol 62 (4) ◽  
pp. 913-924 ◽  
Author(s):  
Karl M Polivka
Keyword(s):  
Interspecific Competition ◽  
Resource Availability ◽  
Large Scale ◽  
Substantial Reduction ◽  
Fish Growth ◽  
Matching Theory ◽  
Temporal Scales ◽  
Specific Effects ◽  
Resource Matching ◽  
Number Of Individuals

I used field observations, assays, and experiments with the euryhaline cottid Cottus aleuticus to evaluate the extent to which average resource availability drives the large-scale distribution of these fish among upstream and estuarine habitats and how interspecific competition from a congener affects its performance in the estuary. Population densities of C. aleuticus were only consistent with resource densities across years during two of five study years, indicating a lack of resource matching at large temporal scales. On shorter temporal scales, fish growth rates that were two to three times higher in the estuary compared with the stream were inconsistent with the predictions of resource matching theory. A manipulation of C. aleuticus density showed that the estuary could support at least twice the number of individuals that occurred there; thus, the profitable estuary is underutilized. Interspecific competition with Cottus asper was partially responsible for this underutilization as indicated by a substantial reduction in growth and condition among C. aleuticus individuals in experimental manipulations that compared intra- and inter-specific effects. Observed spatial overlap between these two cottids combined with the results of the competition experiment suggests that C. aleuticus is more strongly limited in its ability to use estuarine habitats opportunistically by interspecific competition than by intraspecific competition.

scholarly journals Dynamics of Spruce budworms and single species competition models with bifurcation analysis

2020 ◽  
Vol 9 (6) ◽  
pp. 217-222
Author(s):  
Farah Tasnim ◽  
Md. Kamrujjaman
Keyword(s):  
North America ◽  
Mathematical Models ◽  
Bifurcation Analysis ◽  
Population Model ◽  
Choristoneura Fumiferana ◽  
Single Species ◽  
Species Competition ◽  
Numerical Examples ◽  
Competition Models ◽  
Forest Lands

Choristoneura Fumiferana is perilous defoliators of forest lands in North America and many countries in Europe. In this study, we consider mathematical models in ecology, epidemiology and bifurcation studies; the spruce budworm model and the population model with harvesting. The study is designed based on bifurcation analysis. In particular, the results support population thresholds necessary for survival in certain cases. In a series of numerical examples, the outcomes are presented graphically to compare with bifurcation results.

scholarly journals What Drives Life-History Variation in the Livebearing Fish Poeciliopsis prolifica? An Assessment of Multiple Putative Selective Agents

2021 ◽  
Vol 8 ◽  
Author(s):  
Andrea J. Roth-Monzón ◽  
Mark C. Belk ◽  
J. Jaime Zúñiga-Vega ◽  
Jerald B. Johnson
Keyword(s):  
Life History ◽  
Population Density ◽  
Interspecific Competition ◽  
Resource Availability ◽  
Life History Traits ◽  
Life History Evolution ◽  
Embryo Size ◽  
Selective Pressures ◽  
Selective Agents ◽  
Livebearing Fish

Life-history traits are directly linked to fitness, and therefore, can be highly adaptive. Livebearers have been used as models for understanding the evolution of life histories due to their wide diversity in these traits. Several different selective pressures, including population density, predation, and resource levels, can shape life-history traits. However, these selective pressures are usually considered independently in livebearers and we lack a clear understanding of how they interact in shaping life-history evolution. Furthermore, selective pressures such as interspecific competition are rarely considered as drivers of life-history evolution in poeciliids. Here we test the simultaneous effects of several potential selective pressures on life-history traits in the livebearing fish Poeciliopsis prolifica. We employ a multi-model inference approach. We focus on four known agents of selection: resource availability, stream velocity, population density, and interspecific competition, and their effect on four life-history traits: reproductive allocation, superfetation, number of embryos, and individual embryo size. We found that models with population density and interspecific competition alone were strongly supported in our data and, hence, indicated that these two factors are the most important selective agents for most life-history traits, except for embryo size. When population density and interspecific competition increase there is an increase in each of the three life-history traits (reproductive allocation, superfetation, and number of embryos). For individual embryo size, we found that all single-agent models were equivalent and it was unclear which selective agent best explained variation. We also found that models that included population density and interspecific competition as direct effects were better supported than those that included them as indirect effects through their influence on resource availability. Our study underscores the importance of interspecific competitive interactions on shaping life-history traits and suggests that these interactions should be considered in future life-history studies.

scholarly journals An impressive capacity for cold tolerance plasticity protects against ionoregulatory collapse in the disease vector, Aedes aegypti

2019 ◽  
Author(s):  
Amanda Jass ◽  
Gil Y. Yerushalmi ◽  
Hannah E. Davis ◽  
Andrew Donini ◽  
Heath A. MacMillan
Keyword(s):  
Aedes Aegypti ◽  
Cold Acclimation ◽  
Recovery Time ◽  
List Type ◽  
Cold Temperatures ◽  
Beneficial Effects ◽  
Disease Vector ◽  
Chill Coma ◽  
Insect Biogeography ◽  
Do So

AbstractThe mosquito Aedes aegypti is largely confined to tropical and subtropical regions but its range has recently been spreading to colder climates. As insect biogeography is closely tied to environmental temperature, understanding the limits of Ae. aegypti thermal tolerance and their capacity for phenotypic plasticity is important in predicting the spread of this species.In this study we report on the chill coma onset and recovery, as well as low temperature survival phenotypes of larvae and adults of Aedes aegypti that developed or were acclimated to 15°C (cold) or 25°C (warm).Developmental cold acclimation did not affect chill coma onset of larvae but substantially reduced chill coma onset temperatures in adults. Chill coma recovery time was affected by both temperature and the duration of exposure, and developmental and adult acclimation both strongly mitigated these effects and increased rates of survival following prolonged chilling.Female adults were far less likely to take a blood meal when cold acclimated and simply exposing females to blood (without feeding) attenuated some of the beneficial effects of cold acclimation on chill coma recovery time.Lastly, larvae suffered from hemolymph hyperkalemia when chilled, but development in the cold attenuated the imbalance, which suggests that acclimation can prevent cold-induced ionoregulatory collapse in this species.Our results demonstrate that Aedes aegypti larvae and adults have the capacity to acclimate to cold temperatures and do so at least in part by better maintaining ion balance in the cold. This ability for cold acclimation may facilitate the spread of this species to higher latitudes, particularly in an era of climate change.

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