Toxicity of plumbagin and juglone to the eggs of the cotton stainer,Dysdercus koenigii

Toxicity of two plumbaginoids viz., plumbagin and juglone to the eggs of the cotton stainer,Dysdercus koenigii was studied by a residual film technique. Of these two, plumbagin showed the higher toxicity against different-age eggs with LC₅₀ ranging from 0.0044 to 0.0066%. Eggs showed low susceptibility in the middle of embryogenesis. The toxicity of plumbaginoids, especially plumbagin, is discussed in relation to mode of action and prospects of its use as an ovicide in control of the insect.