Screwworm pupae. - - New World Screwworm Fly. A type of parasitic insect known as new world screwworm fly (Cochliomyia hominivorax Coquerel) that causes widespread damage to livestock in the western hemisphere, is now present in North Africa and could pose a similar threat to Africa, the Middle East and southern Europe. When experts confirmed the insect?s presence in North Africa, the Food and Agriculture Organization of the United Nations (FAO) immediately notified its member states in the threatened areas warning that the parasite could have disastrous consequences to livestock, wildlife and even the human population. It is feared that the insect can spread rapidly to areas with suitable conditions in other countries causing damage to livestock industries. FAO called for urgent surveillance, identification of the parasite and information on confirmed cases, and also offered technical assistance. The screwworm is considered one of the most important insect pests of livestock in the western hemisphere, with economic consequences estimated at hundreds of millions of dollars per year. It can be eradicated using the sterile insect technique as has been successfully done in the USA, Mexico and Guatemala. However, such a control programme will take time to develop and is costly.