Toxicity of the blue-green alga Oscillatoria agardhii to the mosquito Aedes aegypti and the shrimp Artemia salina.

The cyanobacterium Oscillatoria agardhii 27, which does not produce mammalian neuro- or hepatotoxins, was highly toxic to the larval stages of the yellow fever mosquito Aedes aegypti: its 24-h LC50 values against fourth-and second-instar larvae of A. aegypti were 8.7 and 6.1 μg live cells/ml, respectively. The toxin was water-soluble and was partially purified but the chemical nature of the toxic compound(s) is still unknown. Aqueous solutions were also toxic to the newborn larvae of the brine shrimp, Artemia salina, used for the bioassay. The toxic activity of these solutions decreased markedly on heating to ≧90°C for 15 min.