Relative Growth Relations in Morphological Characters of the Rice Stem Borer, Chilo suppressalis WALKER

Abstract

The relative growth relations observed in morphological characters of the rice stem borer, Chilo suppressalis, captured by light trap and reared in the laboratory are presented in this papar.
The relative growth relations are shown by an equation: y=bx^α (HUXLEY, 1932)
Values of αs in this equation were approximately 1 for length of fore-wing vs. adult body length or expansion of fore-wings and for adult body weight vs. number of eggs in ovary, and 3 for length of fore-wing vs. adult body weight or number of eggs in ovary. The relative growth relation was also found between larval and adult characters that is, αs were approximately 1 for larval weight vs. number of eggs in ovary and 0.4 for larval weight vs. length of fore-wing. Values of αs for length of fore-wing vs. adult head width were lesser than 1.
The index of wing load of males (1st generation 2.0, 2nd generation 1.9) was lighter than that of females (3.1 and 3.6, respectively). There were no significant differences in relative growth relations between the moths grown on the rice plant and on a water oat, Zizanla latifolia.