ABSTRACT
Acute lethal toxicity of Cyanobacteria [blue-green algae] was investigated against 3rd larval stages of Musca domestica and Culex pipiens and 4th larval stages of Spodoptera littoralis and Agrotis ipsilon. The LD50s were 1.94, 2.33, 7.59 and 9.10 mug for M. domestica, C. Pipiens, S. Littoralis and A. ipsilon, respectively. The slope functions were 4.045 +/- 0.332 [M. domestica], 4.122 +/- 0.336 [C. Pipiens], 4.15 +/- 0.35 [S. littoralis] and 3.72 +/- 0.34 [A. ipsilon]. These LD50s markedly affected the larval, pupal and adult time of durations as well as suppressed the oviposition of the survivor adults. The LD50 did not show any marked effect as serum acetyl cholinesterase and gave nearly the same level of AchE activity. No doubt, Cyanobacteria are safe and promising agent for insect control