The eggs of three Amazonian species of the genus Mansonia (Diptera: Culicidae) were analyzed using morphological and morphometric characters. Eggs of Mansonia humeralis Dyar & Knab, 1916 were morphologically different from those of Mansonia titillans (Walker, 1848) and Mansonia amazonensis (Theobald, 1901), which were more similar to each other according to linear and geometric morphometry. A principal component analysis generated from elliptic Fourier contour data (PC1—92.6% and PC2—2.61%) indicated that Ma. amazonensis and Ma. titillans are more similar to each other than either is to Ma. humeralis. Discriminant multivariate analysis was highly accurate with only four classification errors and a 90% accuracy rate. The results indicate that the three Amazonian species can be precisely distinguished in the egg stage and that geometric morphometry based on elliptic Fourier contours is a promising method for distinguishing eggs of species of Mansonia. An identification key based on egg morphology is provided to distinguish the four Neotropical species.

Background: Aedes aegypti is currently controlled with synthetic larvicides; however, mosquitoes have become highly resistant to these larvicides and difficult to eradicate. Studies have shown that insecticides derived from fungal extracts have various mechanisms of action that reduce the risk of resistance in these mosquitoes. One possible mechanism is uncontrolled production of reactive oxygen species (ROS) in the larvae, which can cause changes at the cellular level. Thus, the crude extract of Xylaria sp. was evaluated to investigate the oxidative effect of this extract in A. aegypti larvae by quantifying the oxidative damage to proteins and lipids. Methods:The larvicidal potential of the crude extract of Xylaria sp. Was evaluated, and the extract was subsequently tested in human lung fibroblasts for cytotoxicity and ROS production. ROS level was quantified in the larvae that were killed following exposure to the extract in the larvicide test. Results:The crude extract of Xylaria sp. Caused cytotoxicity and induced ROS production in human lung fibroblasts and A. aegypti larvae, respectively. In the larvicide trial, the extract showed an LC 50 of 264.456 ppm and an LC90 of 364.307 ppm, and was thus considered active. The extract showed greater oxidative damage to lipids and proteins, with LC 90 values of 24.7 µmol MDA/L and 14.6278 ×10 -3 nmol carbonyl/ mg protein, respectively.Conclusions: Crude extracts of Xylaria sp. induced oxidative stress that may have caused the mortality of A. aegypti larvae.

Background: Aedes aegypti is the primary vector of viruses, such as Zika, chikungunya, yellow fever, and dengue. In this context, a biomonitored chemical study was conducted to evaluate the activity of the crude extract of the endophytic fungus Phomopsis sp. against the larvae of Aedes aegypti.Methods: Crude extract, fractions, and isolated substances were evaluated in in-vitro assays against third-stage larvae of Aedes aegypti. Results:We isolated 3-nitropropionic acid with an LC 50 of 15.172 ppm and LC 90 of 18.178 ppm after 24 hours of larval exposure. Conclusions:The results indicated that 3-nitropropionic acid exerted larvicidal activity.

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