Baccharis dracunculifolia (Asteraceae) essential oil toxicity to Culex quinquefasciatus (Culicidae)

Abstract

The control of mosquitoes by means of chemical insecticides has been a problem, mainly due to the possibility of resistance developed by insects to xenobiotics. For this reason, demand for botanical insecticides has increased. In this sense, the present work aims to verify the susceptibility and morphological and biochemical alterations of Culex quinquefasciatus larvae after exposure to essential oil (EO) of leaves of Baccharis dracunculifolia. To observe the larvicidal action, larvae were exposed to EO at concentrations of 25, 50, 100, and 200 mg/L, until their emergence to adults. The control group was exposed to deionized water and dimethyl sulfoxide. Morphological analyses were also carried out using hematoxylin and eosin, mercury bromophenol blue, Nile blue, and periodic acid Schiff. Biochemical analyses of total glucose, triacylglyceride (TAG), protein, and acetylcholinesterase levels were performed. The phytochemical analysis of the EO showed (E)-nerolidol as the major compound (30.62%). Larvae susceptibility results showed a LC of 34.45 mg/L for EO. Morphological analysis showed that there were histological changes in midgut. For biochemical analyses, the glucose level in the larvae exposed to EO for 24 h decreased significantly, unlike the TAG levels, which increased. The total protein level of the larvae also increased after exposure for 24 h, and acetylcholinesterase levels decreased significantly. Taking all our data into account, we can conclude that EO causes destabilization in larva, leading to histological changes, metabolic deregulation and, consequently, their death.

Shedding light on toxicity of SARS-CoV-2 peptides in aquatic biota: A study involving neotropical mosquito larvae (Diptera: Culicidae)

“…The larvae of C. quinquefasciatus used in this study were obtained in a semi-natural breeding place maintained at the Bioterium of the Biological Research Laboratory of the Federal Goiano Institute - Campus Urutaí (GO, Brazil), according to procedures recommended by Gerberg et al (1994) which were also used by Alves et al (2018) and Alves et al (2020) . Briefly, the females lay on plastic trays (50 cm × 40 cm x 25 cm) covered with Sombrite®60 % mesh, containing 25 L of deionized water and 20 g of feed used to feed mice.…”

Larvicidal Activity of Eucalyptus globulus (Myrtaceae) and Origanum majorana (Lamiaceae) Essential Oils against the Sand Fly Phlebotomus papatasi (Diptera: Psychodidae)

“…The peritrophic matrices are considerable physical barriers between the contents of the insect-gut lumen and the underlying digestive epithelial cells of the insect midgut (Tellam, 1996). The observed histopathological effect on the midgut of P. papatasi larvae due to E. globulus and O. majorana oils were similar to the effect of other xenobiotics which triggered a detoxification process (Alves et al, 2018).…”

Herbal oils in healthcare: a review

“…Among the reports already available, it is possible to observe the essential oils of several species with anti-inflammatory potential (Florão et al, 2012;Guimaraes et al, 2021), fungicidal, anti-bactericidal (Petenattiet al, 2000Cobos et al, 2001;Demo et al, 2005) antiulcerogenic (Klopell et al, 2007) and as an insect repellent (Abad;Bermejo, 2007;Garcia et al, 2005;Alves et al, 2018). Furthermore, one of the plants that has its known medicinal use in Brazil is Carqueja (Baccharis spp.)…”