Mosquitocidal activity of Solanum xanthocarpum fruit extract and copepod Mesocyclops thermocyclopoides for the control of dengue vector Aedes aegypti

Abstract

The present study was carried out on Solanum xanthocarpum fruit extract and copepods Mesocyclops thermocyclopoides, which were assessed for the control of dengue vector, Aedes aegypti, under laboratory conditions. The medicinal plants were collected from the outskirts of Bharathiar University, Coimbatore, Tamil Nadu, India. The shade-dried fruit materials were extracted by employing the Soxhlet apparatus with methanol (organic solvent) 8 h and the extracts were filtered through a Buchner funnel with Whatman number 1 filter paper. The fruit extracts were concentrated at reduced temperature on a rotary vacuum evaporator and stored at a temperature of 4°C. S. xanthocarpum fruit extract (SXFE) at 100, 150, 200, 250, and 300 ppm caused significant mortality of Ae. aegypti. The LC(50) and LC(90) of S. xanthocarpum against the first to fourth instar larvae and pupae were 170.91, 195.07, 221.45, 253.18, and 279.52 ppm and 320.62, 366.48, 410.20, 435.16, and 462.10 ppm, respectively. A study was conducted to test whether the predatory efficiency of copepods on first instars changed in the presence of SXFE. The percentage of predatory efficiency of copepod was 6.5 % in treatments without SFXE and the percentage of predatory efficiency increased up to 8.7 % when copepods were combined with SFXE. This increase in predation efficiency may be caused by detrimental effects of the SFXE active principle compound (solanocarpine and solanocarpidine) on the mosquito larvae. Repeated application of fruit extract of S. xanthocarpum does not cause changes in copepod populations because fruit extract is highly degradable in the environment. Therefore, the present investigation clearly exhibits that the fruit extract of S. xanthocarpum and copepod M. thermocyclopoides could serve as a potential of highest mortality rate against the mosquito larvae under laboratory conditions. This is a new eco-friendly approach for the control of Ae. aegypti mosquito as target species. Therefore, this study provides the first report on the combined effect of mosquitocidal activity of this fruit extract and copepods of M. thermocyclopoides against dengue vector Ae. aegypti from India.

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

“…This has been demonstrated for various species of copepods (e.g., M. edax [58], M. thermocyclopoides [54], Megacyclops formosanus [72], M. aspericornis [56]), tadpoles (e.g., Hoplobatrachus tigerinus [70]), fish (e.g., Gambusia affinis [29], Poecilia reticulata [73], Carassius auratus [74], Aplocheilus lineolatus [21]), odonate young instars (e.g., Anax immaculifrons nymphs [75], Brachydiplax sobrina nymphs [76]), and water bugs (e.g., Diplonychus indicus [77]). This opportunity should be explored further, since the exploitation of synergies between ultra-low doses of plant-fabricated mosquitocides and biological control agents may represent a further control option readily available in tropical and sub-tropical developing countries worldwide [13].…”

“…Several species of copepods, such as Cyclops vernalis , Megacyclops formosanus , Mesocyclops (M.) aspericornis , M. edax , M. guangxiensis , M. longisetus and M. thermocyclopoides , have been reported as active predators of mosquito young instars [32,52,53,54,55,56,57,58]. Operationally, the use of copepod predators against mosquitoes in urban and semi-urban habitats is not expensive and requires minimal labour for colony maintenance, highlighting their easy and cheap potential as mass-reared biocontrol agents [59,60].…”

Prevention and Control Strategies to Counter Zika Virus, a Special Focus on Intervention Approaches against Vector Mosquitoes—Current Updates

“…Mesocyclops thermocyclopoides is a predator of the Ae. aegypti mosquito and its predatory efficiency increases by 8.7% in the presence of Solanum xanthocarpum fruit extract (Mahesh Kumar et al, 2012 ). Simple protocols have been developed for breeding Copepod species for maintenance and mass propagation prior to their release as biocontrol measures (Suarez et al, 1992 ).…”

Recent Advances on the Use of Biochemical Extracts as Filaricidal Agents

“…A combined bioefficacy of the fruit extracts of Solanum xanthocarpum and copepods of Mesocyclops thermocyclopoides was assessed for the control of A. aegypti , respectively [ 91 ]. The S. xanthocarpum fruit extract revealed significant larval mortality to A. aegypti 1st–4th instar larvae exposed to dosage of 100–300 ppm (the highest LC 50 = 253.18 ppm).…”

“…The authors reported an increase in the percentage of copepod predatory efficiency in the extract treated sample (8.7%) as compared to 6.5 % in samples without the extract. This increase in predation efficiency was opined by the authors to possibly be due to the detrimental effects of the extract active principle compound (solanocarpine and solanocarpidine) on the mosquito larvae [ 91 ].…”