The Entomopathogenic Fungi and for Management of the Melon Fly : Pathogenicity, Horizontal Transmission, and Compatability with Cuelure.

In the laboratory, the pathogenicity of thirteen isolates of (Metschnikoff) Sorokin and two isolates of (Balsamo) Vuillemin against the melon fly (Coquillett) were assessed by exposing adults to 0.3 g of dry conidia (~3 × 10 conidia) of each isolate for 5 min and monitoring mortality for up to 5 days. Compatibility with a male pheromone, cuelure, (4-(p-acetoxyphenyl)-2-butanone), was determined by testing conidial germination and germ tube growth of the most promising isolate, ICIPE 69, in the presence of cuelure at different temperatures. For horizontal transmission, the flies were separated by sex, separately exposed to ICIPE 69, and subsequently mixed with non-exposed flies from the other sex. The most pathogenic isolates were ICIPE 69, 18, and 30, causing mortalities of 94, 87, and 81%, with 5 days post-exposure, respectively. ICIPE 69 caused the highest pupal mortality of 74%, with 15 days post-exposure. Horizontal transmission of ICIPE 69 among male and female was confirmed by 59 and 67% mortality after exposure to infected donor males and females, respectively. ICIPE 69 affected the oviposition, but not hatchability, of infected females. ICIPE 69 is, therefore, a potential isolate for biopesticide development for management in cucurbit production systems.