Larval and gut enzyme toxicity of n-hexane extract Epaltes pygmaea DC. against the arthropod vectors and its non-toxicity against aquatic predator

Abstract

The crude n-hexane extracts Epaltes pygmaea (NH-Epx) displayed a steady larval toxicity against Culex quinquefasciatus and Aedes aegypti at the maximum dosage of 125 ppm. The level of α- and β carboxylesterase activity was downregulated to the sub-lethal dosage of NH-EPx (75 ppm) in both vectors. The level of GST and CYP450 gets upregulated. The LC₅₀ and the LC₉₀ of NH-EPx were observed at 63 and 117 ppm and 73 and 120 ppm dosage against both the vectors, respectively. NH-EPx treatment showed morphological alterations in the gut tissues. The non-target screening recommends that NH-EPx is safe against aquatic predator.

Keywords:

• Epaltes
• n-hexane
• larvicide
• CYP450
• repellent and aquatic predator

Disclosure statement

The authors declare no conflict of interest.

Additional information

Funding

This research work was partially supported by Chiang Mai University. Also, the author P. V. was financially supported by the Early Career Research Award funded by Science and Engineering Research Board [DST-SERB], Government of India [FILE NO.ECR/2018/000552].