Neochloris aquatica as a novel mosquitocidal control agent

GIL, M. FLORENCIA; FASSOLARI, MARISOL; BATTAGLIA, MARINA E.; BERÓN, CORINA M.

Maryland

Congreso; 55 Anual Meeting of the Society for Invertebrate Pathology; 2023

During field sampling, in artificial mosquito breeding sites, a group of discarded tires with accumulated rainwater were found. Surprisingly, only one of them contained a bright green culture without mosquito larvae, while the other surrounding tires had a large number of them. The objective of this work was to analyze the effect of the microalga identified as Neochloris aquatica, on larval development or toxic action against Cx. quinquefasciatus, Ae. aegypti and Ae. albopictus. Additionally, microalga effect over oviposition site preference of Cx. quinquefasciatus gravid females was explored. In oviposition site choice tests offering microalga culture or only water, gravid Cx. quinquefasciatus females chose microalga suspension, although neonate larvae did not survive in this substrate. In the bioassays carried out with second-instar larvae using the three mosquito species, larval development was arrested in second/third larval instar when they fed on microalga as only food source. When the microalga suspension was supplemented with a balanced diet, Cx. quinquefasciatus and Ae. albopictus larvae were able to reach adulthood; however, aborted pupae were observed during the emergence to their adult forms. Results from midgut enzyme activity assays showed that in both species, Cx. quinquefasciatus and Ae. albopictus larvae, were capable of digesting the microalga, indicating that the arrest in larval development is not due to a nutritional requirement. Moreover, drastic effects on larval development, metamorphosis, and adult behavior of Ae. albopictus were also registered when larvae fed on the supernatant microalgae cell-free culture supplemented with balanced diet. These results are promising to continue studying the use of the microalga Neochloris aquatica as a potential biocontrol agent.