A mosquito predator survey in Townsville, Australia, and an assessment of Diplonychus sp. and Anisops sp. predatorial capacity against Culex annulirostris mosquito immatures

Abstract

A twelve-month survey for mosquito predators was conducted in Townsville, Queensland, Australia, which is located in the arid tropics. The survey revealed the presence of five predaceous insects but only Anisops sp. (backswimmers) and Diplonychus sp. were common. Predatorial capacity and factors influencing this capacity were then assessed for adult Anisops sp. and adult and nymph stages of Diplonychus sp. against Culex annulirostris mosquito immatures under laboratory conditions. Predatorial capacity bioassays showed that adult Diplonychus sp. preyed upon both larval and pupal stages of Cx. annulirostris quite successfully. Nymphs of Diplonychus sp. proved to be more successful with smaller prey immatures, and Anisops sp adults did not prey successfully on any prey pupae. Increasing the foraging area and introducing aquatic vegetation significantly reduced the predatorial capacity of Diplonychus sp. nymphs, while only vegetation and not foraging area had a significant effect on adult Diplonychus sp. predation capacity. Overall, adult Diplonychus sp. proved to be a more efficient predator than Anisops sp., and field trials are now recommended to further assess the potential of Diplonychus sp. as a biocontrol agent.

The Roles of Predators, Competitors, and Secondary Salinization in Structuring Mosquito (Diptera: Culicidae) Assemblages in Ephemeral Water Bodies of the Wheatbelt of Western Australia

“…However, we were unable to implicate dytiscids, or any other individual predator group, as widespread regulators of mosquito abundance, by a negative association, across the landscape. This may be because of the level of taxonomic discrimination, but most predators are polyphagous (Campos et al 2004, Cisneros and Rosenheim 1997, Mogi 2007, Shaalan et al 2007, Woodward and Hildrew 2002. It is possible we consistently missed some predators, through sampling error.…”

“…Much recent literature has focused on effects of odonates and hemipterans as predators and oviposition deterrents of mosquitoes (Arav and Blaustein 2006;Blaustein 1998;Blaustein et al 2004;Bond et al 2006;Quiroz-Martinez et al 2005;Shaalan et al 2007;Spencer et al 2002;Stav et al 1999Stav et al , 2000Yanoviak 1999Yanoviak , 2001. We found a negative, but nonsigniÞcant, trend between the density of mosquitoes and densities of Odonata and Hemiptera (linear regressions: r 2 ϭ 0.022, F 1, 178 ϭ 4.001, P ϭ 0.047, and r2 ϭ 0.041, F 1, 178 ϭ 7.581, P ϭ 0.007, respectively, critical ␣ ϭ 0.002).…”

Biological Control of Mosquito Vectors: Past, Present, and Future

“…Indeed, mosquito young instars are preyed upon by a large number of aquatic organisms including fish [21,27,28,29], amphibians [30,31], copepods [32,33], odonate young instars [34], water bugs [35,36,37,38], and even larvae of other mosquito species [39,40]. Biological control of mosquitoes using vertebrates has mostly focused on the role of larvivorous fish that consume the aquatic larval stage of mosquitoes [26].…”

Species Interactions Among Larval Mosquitoes: Context Dependence Across Habitat Gradients

“…In contrast, habitat structure significantly reduced the success of visually hunting hemipterans Diplonychus sp. (123) and Notonecta undulata (125) attacking Culex . Further investigations of the effects of habitat structure on the success of pool-dwelling invertebrate predators are needed.…”

“…Many mosquitoes co-occur with multiple predators (23, 51, 60, 71, 123, 129, 141), so MPEs seem likely.…”