Predatory efficacy of five locally available copepods on Aedes larvae under laboratory settings: An approach towards bio-control of dengue in Sri Lanka

Abstract

Many countries are in search of more effective and sustainable methods for controlling dengue vectors, due to undeniable inefficiencies in chemical and mechanical vector control methods. Bio-control of vectors by copepods is an ideal method of using interactions in the natural ecosystem for vector management, with minimum consequences on the environment. Current study determined the predatory efficacy of five locally abundant copepod species on, Aedes larvae under laboratory conditions. Copepods were collected from the pre-identified locations within the districts of Gampaha and Kandy, and identified morphologically. Individual species of copepods were maintained as separate colonies with Paramecium culture and wheat grain as supplementary food. Five adult copepods of each species was introduced into separate containers with 200 larvae (1 st instar) of Aedes aegypti . Number of larvae survived in containers were enumerated at 3 hour intervals within a duration of 24 hours. Each experiment was repeated five times. The same procedure was followed for Ae . albopictus . Significance in the variations among predation rates was evaluated with General Linear Modelling (GLM) followed by Tukey’s pair-wise comparison in SPSS (version 23). Significant variations in predation rates of studied copepod species were reported (p<0.05), whereby M . leuckarti indicated the highest followed by M . scrassus , while C . languides indicated the lowest predatory efficacy. The effect of different Aedes larval species on the predation rates of copepods remained significant (p<0.05), even though the effect on predatory efficiency was not significant. Based on the findings, both M . leuckarti and M . scrassus , with the highest predatory efficiencies, could be recommended as potential candidates for biological controlling of Aedes vectors in Sri Lanka.

Naturally Occurring Microbiota Associated with Mosquito Breeding Habitats and Their Effects on Mosquito Larvae

“…Besides, Udayanga et al [ 46 ] found that the predatory efficiencies varied significantly among the copepod species; Mesocyclops leuckarti showed the highest predatory efficiency for Ae . aegypti and Ae .…”

“…aegypti and Ae . albopictus larvae [ 46 ]. Mesocyclops aspericornis was the most effective predator of Aedes mosquitoes while Mesocyclops darwini was less efficient [ 43 ].…”

Diversity and Species Composition of Microbiota Associated with Mosquito Breeding Habitats: A Study from Kurunegala District in Sri Lanka

“…Several such species of copepods, namely, Cyclops vernalis, Megacyclops formosanus, Mesocyclops aspericornis, M. edax, M. guangxiensis, M. longisetus, and M. thermocyclopoides, were reported as active predators of young mosquito instars [40,41]. Udayanga et al [42] reported that Mesocyclops leuckarti had a successful predatory effect on Ae. aegypti and Ae.…”

A Review: Aedes-Borne Arboviral Infections, Controls and Wolbachia-Based Strategies

“…Experimental vector control methods include the introduction of biological agents such as larvivorous fish [ 111 ], copepods (a group of small crustaceans) [ 112 ] or Bacillus thuringiensis [ 113 ], typically for larvae control. A study investigating the community effectiveness and efficacy of the use of larvivorous fish for dengue vector control reported that although the use of larvivorous fish could be effective in reducing the immature vector stages in small settings such as containers, these results could be minimal as it would require large coverage of multiple production of larvivorous fish containers to achieve any impact in an area of dengue endemicity [ 111 ].…”