Citrus Rind Borer (CRB), Prays endolemma Diakonoff,is the number one menace of Pummelo Industry in the Philippines. The dissected female genitalia (n=171) showed a sclerotized wide lower part of the ductus bursae forming two broad sclerites (cestum), each bearing a dentate ridge. This is characteristic of the species. Larva was the destructive stage of the insect. It fed on the tissues beneath the exocarp, particularly on the 'flavedo'. The larva underwent five instars before it crawled out of the rind to pupate. It appears that all fruits in one fruiting season could possibly be infested with CRB, without the intervention of any control measures.