Abstract
Virulence of five different fungal isolates, Trichoderma longibrachiatum, T. harzianum, Aspergillus terreus, A. niger and Penicillium oxalicum was evaluated against the adult fruit fly, Ceratitis capitata (Wied.) to control or suppress its population before the application of the sterile insect technique (SIT) in the field. Filtrate and three spore suspension concentrations (10(4), 10(6) and 10(8) spores/ml) of each fungal isolate were applied to the adult flies (> 24 h. old). Some biological aspects such as adult survival (after 5, 10 and 15 days from emergence), female fecundity and male sterility throughout two weeks were studied. The results revealed that there were significant decreases (P<0.05) in the survival of males at all ages. Males were more susceptible than females (P<0.05). Moreover, the results indicated significant decreases (P<0.05) in the average number of eggs laid per female per day throughout two weeks when T longibrachiatum (108 spores/ml), T. harzianum and A. niger (filtrate, 10(4), 10(6) and 10(8) spores/ml) and P. oxalicum (10(4), 10(6) and 10(8) spores/ml) were applied to adults. However, significant increases (P<0.05) were observed in the male sterility when T longibrachiatum (filtrate and 10(8) spores/ml), T. harzianum (filtrate, 10(6) and 10(8) spores/ml). A. niger (10(6) and 10(8) spores/ml) and P. oxalicum (10(4), 10(6) and 10(8) spores/ml) were used. Laboratory results revealed that the tested fungi can be applied in the field under controlled humidity for suppressing population density of the Mediterranean fruit fly by using the attractant-contaminant traps to transmit the fungal infection to the rest of the population.