Predators ofAnopheles gambiaesensu lato (Diptera: Culicidae) Larvae in Wetlands, Western Kenya: Confirmation by Polymerase Chain Reaction Method

Abstract

Polymerase chain reaction analysis was performed to determine whether mosquito predators in wetland habitats feed on Anopheles gambiae sensu lato (s.l.) larvae. Aquatic mosquito predators were collected from six wetlands near Lake Victoria in Mbita, Western Kenya. This study revealed that the whole positive rate of An. gambiae s.l. from 330 predators was 54.2%. The order of positive rate was the highest in Odonata (70.2%), followed by Hemiptera (62.8%), Amphibia (41.7%), and Coleoptera (18%). This study demonstrates that the polymerase chain reaction method can determine whether aquatic mosquito predators feed on An. gambiae s.l. larvae if the predators have undigested An. gambiae s.l. in their midgut or stomach. KeywordsAnura; aquatic insect; Coleoptera; Hemiptera; Odonata Despite a long history of efforts to control malaria, malaria remains a major threat to human health. Because the development of a vaccine for malaria has been slow, and parasite resistance to antimalaria drugs is developing rapidly, vector control is considered the most practical method for reducing malaria transmission in developing countries (Trape et al. 2002, Fillinger et al. 2004. Common measures for malaria vector control include bed nets and indoor residual spray using DDT or pyrethroids (Kouznetsov 1977, Lindblade et al. 2006. However, there is concern about toxicity to nontarget organisms (Henry and Kishimba 2006) and vector resistance to chemical insecticides (Corbel et al. 2003, Etang et al. 2003, Hargreaves et al. 2003, Casimiro et al. 2006. Because chemical insecticides also kill predators of mosquitoes (Service 1977), the reduction of predators may increase vectors; therefore, the use of chemical insecticides requires caution.Among the various natural ecological forces controlling vector populations, predation on immature Anopheles gambiae sensu lato (s.l.) appears to be a major factor controlling population size. Predation on An. gambiae larvae contributes considerably (between 13.4 and 84.5%; Chandler and Highton 1977) to overall larval mortality (between 92.6 and 97.1%; 2 Corresponding author: Center for Ecological Research, Kyoto University, 2-509-3 Hirano, Otsu 520-2113, Japan (oobug@hotmail.com). Service 1971Service , 1973Service , 1977. However, little research has been devoted to the effects of larval predation on mosquito population structure and ecology, possibly because of difficulties in identifying and quantifying the impact of the most common predators in the field. NIH Public AccessUsing the serological method, Service (1973Service ( , 1977 found that predators of An. gambiae s.l. include amphibians as well as the insects from the orders Araneida, Odonata, Hemiptera, Hymenoptera, Diptera, and Coleoptera. Schielke et al. (2007) showed that An. gambiae s.l. DNA can be detected after ingestion by members of the families Lestidae (Odonata), Libellulidae (Odonata), and Notonectidae (Hemiptera). Although the authors fed single laboratory-raised An. gambiae sensu stricto to the predators under laboratory condit...

Microbial larvicides for mosquito control: Impact of long lasting formulations ofBacillus thuringiensisvar.israelensisandBacillus sphaericuson non‐target organisms in western Kenya highlands

“…Diverse orders of aquatic vertebrates and invertebrates prey on mosquito larvae (Kweka, Zhou, Gilbreath, et al., 2011; Ohba et al., 2010). In addition to direct predation, the predators cause considerable indirect impacts on the population dynamics of the prey species (Åbjörnsson, Brönmark, & Hansson, 2002; Lima, 1998).…”

“…A variety of non-target organisms has been found to coexist with the mosquito fauna in aquatic habitats (Bukhari, Takken, Githeko, & Koenraadt, 2011;Fillinger, Sombroek, et al, 2009;Service, 1977) and to play a critical role in regulating the aquatic stages of mosquitoes through predation and competition. Diverse orders of aquatic vertebrates and invertebrates prey on mosquito larvae Ohba et al, 2010). In addition to direct predation, the predators cause considerable indirect impacts on the population dynamics of the prey species (Åbjörnsson, Brönmark, & Hansson, 2002;Lima, 1998).…”

Do Chenopodium ambrosioides-Synthesized Silver Nanoparticles Impact Oryzias melastigma Predation Against Aedes albopictus Larvae?

“…The use of chemicals insecticides in routine mosquito control operations led to the development of resistance in the targeted vector species [55,91], as well as to detrimental effects on non-target organisms, with special reference to biological control agents such as larvivorous fishes and other important aquatic predators of Culicidae [26,96,105,112]. Therefore, plant-based insecticides may serve as suitable alternative to synthetic molecules as they are environmentally safe, biodegradable, and are easily available in all parts of the world [4,10,16,53,124].…”

Presence and distribution of mosquito larvae predators and factors influencing their abundance along the Mara River, Kenya and Tanzania

“…Representatives from at least six insect orders, thirteen arachnid families, as well as crustaceans, amphibians, fish, birds and mammals have been reported as being potential mosquito larvae predators (Mogi 2007 , Medlock and Snow, 2008 ). Some studies in Kenya reported mosquito larva predation in rice irrigation schemes and wetlands around Lake Victoria (Mwangangi et al 2007 ; Minakawa et al 2007 ; Ohba et al 2010 ). However, most of these studies limit their research to specific types of aquatic insects, principally the Family Notonectidae (Koivisto et al 1997 ; Murdoch et al 1984 ).…”