title: Mechanistic basis for morphological damage induced by essential oil from Brazilian pepper tree, Schinus terebinthifolia, on larvae of Stegomyia aegypti, the dengue vector.
abstract: BACKGROUND
  Dengue has become the subject of public health programs worldwide. The lack of a vaccine and the high environmental risk of synthetic insecticides, arouse the interest in natural products against this vector. This study aimed to determine the chemical composition of the essential oil of ripe fruits and seeds of Schinus terebinthifolia Raddi; to evaluate the essential oil effect on mortality of Stegomyia aegypti (Linnaeus, 1792) larvae; and to characterize the structural damage suffered by larvae and their association with different contents of essential oil.
  
  
  METHODS
  Ripe fruits and seeds were crunched and their essential oil was extracted through hydrodistillation, purified, and its phytochemical analysis was carried out through High Resolution Gas Chromatography, coupled with Mass Spectrometry. This essential oil was diluted in a 10-point gradient of 86.22 - 862.20 ppm, at regular intervals of 86.22 ppm. Each point received 50 larvae and the assessments of surviving were made at 24, 48 and 72 hours after inoculation. Structural damage was assessed through measurements of thickness with exoskeleton, evaluating the integrity of the head, thorax, abdominal segments, and air siphon, using ImageJ software. Statistical data analysis was carried out through Logistic Regression and Discriminant Analysis.
  
  
  RESULTS
  56 substances were identified, corresponding to 81.67% of the essential oil composition. Larvae were dose-dependent susceptible to the essential oil; the concentration produced a significant effect on larval mortality. Among the major deformations found in the larvae, it was detected inhibition of chitin synthesis by the activity of the oil, thus reducing the deposition of cuticle layers.
  
  
  CONCLUSIONS
  The essential oil caused death in exposed larvae after 72 hours, in a dose-dependent manner. It also changed the structure of exposed larvae, indicating a direct effect on larval exoskeleton. The results open up possibilities for the use of natural products as an alternative to control dipterans.
authors.affiliation: Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. driellepratti@gmail.com.|Programa de Pós-graduação em Ecologia de Ecossistemas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. driellepratti@gmail.com.
authors.forename: Drielle L A
authors.initials: DL
authors.lastname: Pratti
authors.affiliation: Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. alessandro.ramos@uvv.br.|Programa de Pós-graduação em Ecologia de Ecossistemas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. alessandro.ramos@uvv.br.
authors.forename: Alessandro C
authors.initials: AC
authors.lastname: Ramos
authors.affiliation: Programa de Pós-graduação em Ciências Farmacêuticas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. rodrigoscherer@uvv.br.|Tommasi Analítica, Avenida Luciano das Neves, 2016, Divino Espírito Santo, Vila Velha, ES, Brazil. rodrigoscherer@uvv.br.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Scherer
authors.affiliation: Programa de Pós-graduação em Ecologia de Ecossistemas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. zilma@uvv.br.
authors.forename: Zilma M A
authors.initials: ZM
authors.lastname: Cruz
authors.affiliation: Programa de Pós-graduação em Ecologia de Ecossistemas, Universidade Vila Velha - UVV, Rua Comissário José Dantas de Melo, 21, Boa Vista, Vila Velha, ES, Brazil. arygomes@uvv.br.|Tommasi Analítica, Avenida Luciano das Neves, 2016, Divino Espírito Santo, Vila Velha, ES, Brazil. arygomes@uvv.br.
authors.forename: Ary G
authors.initials: AG
authors.lastname: Silva
mesh_terms: D000330:Aedes / Q000033:anatomy & histology / Q000187:drug effects* / Q000254:growth & development* / Q000502:physiology; D027926:Anacardiaceae / Q000737:chemistry*; D060105:Animal Shells / Q000187:drug effects; D000818:Animals; D001938:Brazil; D004305:Dose-Response Relationship, Drug; D007303:Insect Vectors; D007306:Insecticides / Q000302:isolation & purification / Q000494:pharmacology*; D007814:Larva / Q000033:anatomy & histology / Q000187:drug effects / Q000502:physiology; D009822:Oils, Volatile / Q000302:isolation & purification / Q000494:pharmacology*; D016019:Survival Analysis; D013997:Time Factors
chemical_list: D007306:Insecticides; D009822:Oils, Volatile