Economic Importance of Rice Stem-borer (Diopsis macrophthalma) in Malawi

Abstract

SUMMARYExperiments were carried out in which injuries caused by Diopsis macrophthalma larvae were simulated. The results show that these larvae can have negative or positive effects on rice (number of stems, height, maturation time, number of ears and yield), depending on time and level of attack, growing conditions and variety. The results suggest that under normal conditions the effect on number of stems, height, number of ears and yield is positive, and only becomes negative if poor growing conditions are combined with a late, heavy attack. An experiment with Diopsids was carried out to evaluate the simulation experiments.