ATTACK OF THE STEM BORING PEST Ostrinia furnacalis Guenee (LEPIDOPTERA: PYRALIDAE) ON SWEET CORN PLANTS (Zea mays saccharata [Sturt.] Bailey)

Sweet corn (Z. mays saccharata) is widely cultivated around Denpasar City, Bali as a food and vegetable, but the main obstacle to sweet corn cultivation is the attack of stem borers (O. furnacalis). The results of the study showed that the percentage of corn stem borer attacks ranged from 5% to 28%. The number of natural enemies showed 4.13 to 6.26 individuals. The dynamics of the corn stem borer pest population showed a range from 0.09 to 0.23. The relationship between temperature and the population of corn stem borer pests is significantly positive with a correlation coefficient of r = 0.87 (R2 = 0.73), with the regression equation Y1 = 24.097 + 0.190X1 (Y1 = population of stem borers and X1 = temperature). The relationship between stem borers and humidity has a very significant effect with a coefficient (r) = 0.94 (R2 = 0.89), with the regression equation Y1 = -182.815 + 2.729 X2 (X2 = humidity). The relationship between temperature and the population of natural enemies has a significant positive effect with a coefficient of r = 0.853 (R2 = 0.73) with the regression equation Y2 = 21.37 + 0.9367X1 (Y2 = population of natural enemies).