Susceptibility of the Peach Fruit Fly, Bactrocera zonata (Saunders), (Diptera: Tephritidae) to Three Entomopathogenic Fungi

The peach fruit fly, Bactrocera zonato (Saunders) (Diptera. Tephritidae) is one of the most serious polyphagous insect pests in Egypt Its Control depends upon chemical sprays with organophosphate pesticides, especially Malathion mixed with protein baits Then environmental impacts and development of resistance have justified the need to find sustainable control alternatives Therefore, susceptibility of B zonata to three entomopathogenic fungi was studied Laboratory experiments to determine the virulence of the fungi, Beauveria bassiana, Metarhizium anisopliae and Lecanicillium muscarium (formerly Verticilium lecanu) on 2(nd) and 3(rd) instars' larvae, 1 and 6-day old pupae, newly emerged males and females of the pest were conducted at the recommended close 5 g/ liter of water (5 x 10(8) conidia/l) and when each ml was containing 5x10(-5) conidia. Obtained results showed that the Susceptibility of males to the fungi was higher than that of females in both bioassay treatments. The Virulence of Fungi was also higher in oral bioassay than contact one in both sexes Moreover, M anisophae gave higher mortality than B bassiana and L muscarium, reaching 94 4% in males and 76 8%, in females in contact bioassay test Meanwhile, M anisophae gave a mortality level of 100 and 95 2% For males and females, respectively in the oral bioassay. Ill case of M amsophae, median lethal times (LT(50s)) were rather short for males (6 23 8 93 days) than (7.49, 10 89 days) for females, followed by B bassiana, 10 83, 12 69 d For males and 10 17, 14 39 d For females L muscarium showed much longer LT(50)s, 15 32, 18 05 d. for males and 17 02, 22 36 d for Females Data revealed that both 2(nd) instal larvae and 1-day old pupae were more susceptible than 3(rd) instar larvae and 6-day old pupae to all the tested fungi Based oil the obtained results, 2(nd) instar larvae, 1-day old pupae and male adults were used to determine the interactions among the three fungi oil mortality response Results also showed sonic potential effect when M anisopliae was mixed with either B bassiana or L muscarium