Biometrical Analysis Of Leucinodes Orbonalis Guenee On Brinjal

Studies on biometrical analysis were carried out to test the applicability of Dyar's law to the larvae of Leucinodes orbonalis, when reared in BOD incubator (26±1°C, RH 65±5 %) on brinjal. The measurements of head capsule width of the larvae fell into five well defined groups, each indicating an instar. The mean observed (0.23–1.48 mm) and calculated head capsule width (0.25–1.58 mm) and progression factors were close to each other (1.60 and 1.59), which indicated that an increase in head width during successive instars was in geometrical progression and it followed the Dyar's law. The progression factors determined from the body length and width indicated great deviation and supported Przibram's and Megusar theory. The multiple correlation coefficient (R2 = 0.999) also indicated a very high predictability of head capsule width through larval body length and width.