The reproductive status of five species of Chrysomya caught in liver-baited traps in Papua New Guinea was determined. The species trapped were the Old World screw-worm fly, Chrysomya bezziana Villeneuve and the blowflies, C. megacephala (F.), C. saffranea (Bigot), C. rufifacies (Macquart) and C. varipes (Macquart). The results were compared with data obtained by other workers for the Australian sheep blowfly, Lucilia cuprina (Wiedemann) and the American screw-worm fly, Cochliomyia hominivorax (Coquerel).