Phytochemical prospecting and larvicidal bioactivity of janaguba latex
(Himatanthus drasticus) mart. Plumel (Apocynaceae) on Aedes aegypti L. (Diptera:
Culicidae)
Biolarvicide; Arboviruses; Dengue; Phenolic compounds.
Arboviruses are a public health problem. In Brazil, dengue,
chikungunya and Zika, transmitted to humans by female Aedes aegypti L.
The control of this vector takes place mainly through the application of chemical products, in the
However, its unrestrained use has brought serious problems such as damage to the environment,
to non-target species and the resistance of this mosquito strains to such products. So,
The objective of this study was to carry out a phytochemical prospection and evaluate the larvicidal activity
of Himatanthus drasticus latex extracts against A. aegypti. The extracts were obtained
by macerating 5 g of powdered latex separately concentrated in 100 mL of the solvents
methanol, ethyl acetate and hexane. The concentrations of 100, 200, 300, 400 and 500 ppm of
each extract were tested in triplicate with a pyriproxyfen solution as a control
positive and distilled water and dimethylsulfoxide as a negative control. prospecting
phytochemistry of the methanolic extract showed the presence of phenolic compounds, such as
anthocyanins, anthocyanidins, catechins, chalcones, aurones, leucoanthocyanidins and tannins
condensed. The insecticidal bioactivity was more significant for the methanolic extract. At
Lethal concentrations (LC) of the 50 and 90% methanolic extract were 190.76 and 464.74 ppm,
respectively. After 48 hours of exposure, the extracts using methanol, acetate of
Ethyl and hexane in their highest concentrations (500 ppm) caused larval mortality of
100, 73.33 and 66.67%, respectively. These extracts also promoted changes in the
external morphology of the larvae, such as damage to the anal papillae, darkening of the body and
reduction in the number of bristles. The methanolic extract showed greater expressiveness for
morphological changes. H. drasticus latex has larvicidal activity against
third instar of A. aegypti and is more significant when obtained by maceration in
methanol. The methanolic extract of H. drasticus latex contains phenolic compounds with
insecticidal activity against A. aegypti larvae.