INFLUENCE OF INSECT AND SEED SAMPLE SIZE AND HEAT TREATMENT ON THE INFESTATION OF CALLOSOBRUCHVS CHINENS1S (L.) ON MUNGBEAN, VIGNA RADIATA (L) Wilczek *)

Abstrak

The  influence  of  different  insect  and  seed  sample  size  and  heat  treatment  on  the  infestation  of  bean  weevil, Callosobruchus chinensis on mungbean,Vjg/m radiata (L.) Wilczek, was studied. Insect and seed sample size as well as varieties/genotype had significant influence in obtaining large responses in the number of eggs and progenies of the bean weevil. Use of at least 10 adult weevils to infest test samples containing at least 40 seeds for a 5-day oviposition period should produce reliable results when infesting mungbean seeds with unsexed weevils. Dry heat treatment was very effective in disinfesting mungbean seeds from the bean weevil in different developmental stages. It improved germination depending upon the condition of the seed before tr eatment and certain temperature limits. A suggested  treatment for mungbean dismfestation using dry heat would be 60°C and 70°C for  two-and one-hour treatments, respectively at 12% moisture content. For seeds in bulk, 60°C is much preferred.Key words:   Callosobruchus chinensis/ Insect and seed sample size/Mungbean infestation/Heat treatment