Contents lists available at ScienceDirect Ecotoxicology and Environmental Safety journal homepage: www.elsevier.com/locate/ecoenv Enhanced mosquitocidal efcacy of colloidal dispersion of pyrethroid nanometric emulsion with benignity towards non-target species Prabhakar Mishra b ,SnehaDutta a , Manidipa Haldar a , Priyanka Dey a , Drishty Kumar a , Amitava Mukherjee a , Natarajan Chandrasekaran a,∗ a Centre for Nanobiotechnology, Vellore Institute of Technology, Vellore, Tamil Nadu, India b Department of Biotechnology, School of Applied Sciences, REVA University, Bengaluru, Karnataka, India ARTICLEINFO Keywords: Pyrethroid Permethrin Nanoemulsion Larvicidal Pupicidal Biosafety ABSTRACT The rising threat of vector-borne diseases and environmental pollution has instigated the investigation of na- notechnology-based applications. The current study deals with a nanotechnological application involving the usageofnanometricpesticidessuchaspermethrinnanoemulsion.Themeandropletdiameterandzetapotential of the prepared permethrin nanoemulsion were found to be 12.4 ± 1.13nm and −20.4 ± 0.56mV, respec- tively.Thetemporalstabilityofpermethrinnanoemulsionwasfoundtobe4dayswhencheckedintheexternal environment. The permethrin nanoemulsion exhibited LC 50 values of 0.038 and 0.047mgL−1 and 0.049 and 0.063mgL −1 against larval and pupal stages of Culex tritaeniorhynchus and Aedes aegypti, respectively. The re- sults obtained from the larvicidal and pupicidal assay were corroborated with the histopathological and bio- chemical profles of hosts upon treatment with nanometric pesticide. Further, the biosafety studies of the na- nopesticide were carried out against diferent non-target species like freshwater algae (Closterium), Cicer arietinum (Chickpea) and Danio rerio (Zebrafsh), and the mosquitocidal concentration of nanopesticide was found to be non-toxic. The following study, therefore, describes the mosquitocidal efcacy of nanometric pes- ticideformulatedinagreenerapproach,whichcanbecomeasubstituteforconventionalpesticideapplicationin an eco-benign manner. 1. Introduction Aedes aegypti and Culex tritaeniorhynchus are the predominant vec- tors for dengue, chikungunya, and Japanese encephalitis and are pre- valentinthetropicalandsubtropicalregionsaroundtheglobe.Priorto the adult stage, these mosquito species thrive in water bodies ranging from tree holes to old tyres to ephemeral ponds and other stagnant water(Muthenenietal.,2014).Theforemostthrustareaofcontrolling these vectors is killing them at their early life stages via biological or through chemical ways (WHO, 2009), which could annihilate these vectors.Regulatingthemosquitopopulationattheearlyaquaticstages could be an easily implementable practice in any ecological habitat (Djènontin et al., 2014) and requires less usage of pesticides than re- quired to kill adult vector mosquito population. Because of the un- controlledapplicationofconventionalpesticidetowardscontrollingthe mosquito vector population, the mosquito population and other pre- dominant pest and insect species have developed pesticide resistance, and this can further cause environmental hazards (Wattanachai and Tintanon, 1999; Liu et al., 2005; Salahuddin et al., 2004). Some pesticides are water-immiscible, and hence, dissolution of these using organic solvents are excessively practiced all around the globe, which furtherenhancesthetoxicprofletowardsnon-targetspecies.Enormous use of the conventional pesticidal compounds have endowed its sub- stantial efectivity towards elevation in the agricultural yield (FAO, 2005) through combating the pest and other insect vectors (Naik and Prasad, 2006); however, it has simultaneously created havoc in the agriculture and health sector (Bhatnagar, 2001). The insecticide-treated bed nets and indoors residual spraying are some of the strategies, which are involved in combating the transmis- sionofdeadlyvector-bornediseasesaroundtheglobe.Despitethefact that several new synthetic pesticides with signifcant potency have frequently been introduced in the market, their usage will result in a lethal impact towards the ecosystem and human wellbeing eventually (RobertandOlson,1989).Therecentimprovementsinnanotechnology provided potential revolutionization in a variety of applicative strate- giesfromtargeteddrugdeliverytopestcontrol(Aureletal.,2007; Kim etal.,2007; Raietal.,2009; Amerasanetal.,2015).Thenano-derived pesticides tend to have higher efciency in comparison to https://doi.org/10.1016/j.ecoenv.2019.03.096 Received15June2018;Receivedinrevisedform16March2019;Accepted23March2019 ∗ Corresponding author. Senior Professor & Director, Centre for Nanobiotechnology, VIT, Vellore, 632014, India. E-mail addresses: nchandrasekaran@vit.ac.in, nchandra40@hotmail.com (N. Chandrasekaran). Ecotoxicology and Environmental Safety 176 (2019) 258–269 0147-6513/ © 2019 Elsevier Inc. All rights reserved. T