Different treatment dose intervals, dosimetry, methods, and mango cultivars used in each
of the irradiation studies discussed above make it difficult to draw general conclusions about
an effective irradiation dose for mango seed weevil (Table 1). Based on the studies of Seo et
al. (1974) and Heather and Corcoran (1992), an irradiation dose of 100 Gy is adequate to
sterilize mango seed weevil and 300 Gy will usually prevent adult emergence. Studies by
Thomas (1975) and Milne et al. (1977) suggest a higher dose is required to prevent adult
emergence in South Africa. Research in South Africa has focused on obtaining a quicker kill
because, in late season, mango seed weevils occasionally emerge from the ripening fruit on
the tree (Heather 1992). This event is unlikely under conditions in Hawaii and Australia with
early and mid-season mango varieties, where weevils typically emerge from fruit only after
the flesh has decayed on the ground and the seed is exposed. Consequently, it is more difficult
to prevent some emergence of weevils with irradiation in South Africa..