Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development

Abstract

Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level). To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission.

Bacteria-mediated hypoxia functions as a signal for mosquito development

“…They also involve obligate associations where particular species of microbes are directly transferred from parents to offspring or between individuals of the same insect species (1,41). Mosquito larvae can experience resource limitation in the field (42). However, they present the paradoxical situation of hosting highly variable communities of environmentally acquired microbes, yet fail to develop under axenic conditions when provided a nutritionally complete diet.…”

Mosquito distribution in a saltmarsh: determinants of eggs in a variable environment

“…In addition, there was no evident relationship between ostracod presence and mosquito distribution, suggesting that their significance as an aquatic competitor on mosquito egg distribution choices is minimal, and potentially ostracods and Ae. camptorhynchus may occupy separate niches within the water bodies (Rowbottom et al ). Furthermore, there was no evidence that the presence of any other invertebrates found in these soil cores had any importance on Ae.…”

“…However, more recent laboratory evidence suggests this form of competition may have limited effects on Ae. camptorhynchus development (Rowbottom et al ). Currently, little is understood about the distribution of Ae.…”

Fine-temporal forecasting of outbreak probability and severity: Ross River virus in Western Australia

“…The outcome of these environmental drivers can enhance vector–host interactions, viral transmission and spillover to humans [11, 18, 19]. Vectors in particular are highly responsive to changes in environmental conditions, having the greatest potential for rapid translation into increased abundance and infections [15, 20, 21].…”