Vol. 2, Issue 6 (2017)
Pathogenicity of Beauveria bassiana against cucurbit fruit fly Dacus ciliates (loew) Diptera: Tephritidea
Author(s): Mutadar Alaa Faleh, Bassim Shehab Hamad, Ammar Ahmed Sultan
Abstract: The current study was conducted to evaluate the efficiency of three local isolates of Beauveria bassiana on two stages (larvae and adults) of cucurbit fruit fly Dacus cilliatus under laboratory conditions. The results showed that both stages were sensitive to the concentrations of 105, 107 and 109 spores / ml. Depending on the LC50 values the highest efficiency on females was achieved by the isolate Bb100, it was 1 × 102 sporesml. followed by Bb 17 isolate with the median lethal concentration of 1.1 × 105 sporesml. The most severe isolates was Bb 100 depending on LT50 that was 4.15 days followed by Bb47 (4.5 days).
According to LC50 values, Bb100 isolate was the most severe on males, the LC50 value was 8.3 x 103 sporesml. and then Bb 17 (2.7 x 105 sporesml.) and BE47 (5 × 10 6 sporesml.). The results of median lethal time, which expresses on virulence, showed superior of Bb100 with LT50 2.5 days, then the isolate of BE47 (5.5 days) and Bb17 (9 days) at concentration of 109 spores / ml. Females were greater sensitivity than males when exposed to the suspension of all isolates. The effect of B. bassiana isolates on the cucurbits fruit fly larvae was measured depending on the adult’s emergence rates. The reduction rate of adults emergence was increased with increasing of concentration, the highest was at concentration of 109 sporesml. (75%) for the isolate Bb 100 that significantly differed from other isolates, in both of them the reduction rate reached to 66%.