Relative abundance of field bean (Lablab niger Medick) pod-borers and distribution patterns of the borer, Adisura atkinsoni Moore

Studies on the relative abundance of pod-borers and distribution patterns of the dominant borer, Adisura atkinsoni Moore, were conducted at Bangalore (Karnataka, India) with a view to develop a field screening procedure in the field bean, Lablab niger, to pod-borers. Nine species of borers constituted the borer complex on L. niger. The borers population peaked in October. Eggs and early instar larvae of Adisura followed a clumped distribution pattern. Older larvae, however, were distributed uniformly in the field. Adisura moths preferred to lay eggs between 50.8 and 63.5 cm on the erect type of L. niger and between 101.6 and 114.3 cm on the creeping type of the plant. Plant height had a significant positive correlation with the maximum number of Adisura eggs, but up to nearly 115 cm. Adisura eggs peaked in number during October, while larvae did so during November–December. Implications of the aforementioned observations in field screening are suggested.