Mortality of Caribbean fruit fly (Diptera: Tephritidae) immatures in coated fruits.
Hallman G. J., Nisperos-Carriedo M. O., Baldwin E. A., Campbell C. A.
Author Affiliation: Subtropical Horticulture Research Station, USDA-ARS, 13601 Old Cutler Road, Miami, FL 33158, USA.
Journal of Economic Entomology 87 : 752-757
Abstract : The fruit coatings Primafresh 31, Sta-Fresh 360HS, Sta-Fresh 600 and Nature Seal were studied for their ability to kill larvae of Anastrepha suspensa infesting fruits. Mortality in grapefruits ranged from 33% (Primafresh 31) to 100% (Sta-Fresh 600). Methyl cellulose and shellac, known to restrict gaseous exchange, were identified as substances in Nature Seal that reduced survival of the pest; Nature Seal with 4% methyl cellulose and 17% shellac caused 99.2% mortality in grapefruits. Coating of cold-stored mangoes and carambolas did not increase mortality. Hot-air treatment of Nature Seal (2% methyl cellulose plus 10% shellac)-coated grapefruits increased mortality compared with uncoated fruits; when both were exposed to hot air at 48°C for 60 min, no larvae survived treatment of coated grapefruits, whereas 24% survived treatment of uncoated grapefruits. Fruits of Averrhoa carambola immersed in 46°C Nature Seal heated slower than those immersed in 46°C water. More damage occurred to A. carambola immersed in Nature Seal than in water at 46°C. Carbon dioxide and alcohol levels were higher in coated grapefruits, and oxygen levels were lower compared with uncoated grapefruits.