The granulosis virus plays a key role in the management of potato tuber moth in storage. CIP has developed a simple technique for multiplication and formulation of the virus. The dust formulation, produced by selecting and grinding virus-infected larvae from damaged potato tubers and then mixing them with ordinary talc, is used at five kilograms a ton of stored potatoes (20 infected larvae per kilogram). The virus is being produced in Peru, Bolivia, Egypt, and Tunisia. Several other countries and institutions have expressed an interest in having their own production units. Meanwhile, samples are being shipped for testing purposes when requested.

CIP also developed a simple method to multiply the egg-larval polyembryonic parasitic wasp Copidosoma koehleri. This species has been reared and released in Peru, Bolivia, Colombia, Tunisia, Yemen, India, and other countries, in most cases successfully.

Pest incidence can also be reduced through cultural practices such as not planting potato in the warmest and driest seasons, controlling irrigation to prevent soil cracking that allows moths to reach the tubers, hilling-up to properly cover the tubers, using pheromone traps to capture and monitor field populations, and occasionally using a selective insecticide.

Repellent plants such as "muña" (Minthostachys spp., a plant native to the Andes), eucalyptus, or lantana can also help protect stored tubers.

For PTM management, however, resistant plants are not yet part of CIP's program. But a great deal of breeding work is going on, both conventional and genetic engineering, to obtain potato plants that are resistant to the pest and at the same time high yielding and acceptable to farmers and consumers.

To find sources of resistance, CIP scientists screened wild and cultivated potato accessions using the open-container, free-choice infestation method, and recorded the resistant ones. The evaluation of transgenic potato plants containing the B.t. (Bacillus thuringiensis) toxin gene continued with tests under laboratory, greenhouse, and controlled field conditions.