Susceptibility of Ceratitis capitata Wiedemann (Diptera: Tephritidae) to entomopathogenic fungi.
The Mediterranean fruit fly Ceratitis capitata (Wiedemann) is one of the most serious pest of fruits in Syria and present all year round. This fly is active on different host plants, such as mango, peach, fig, apple, pear, and citrus. The number of generations per year varies with local temperatures and host plant. The objective of this research was: to evaluate the pathogenicity of entomopathogenic fungi on adults of C. capitata under laboratory conditions. Flies for experiments were obtained from a population reared in Laboratory conditions at 25 +/- 2 degrees C, 70 +/- 2% RH, and a photoperiod of 16:8 [L: D] h. Four concentrations (3 x 10(4), 3 x 10(5), 3 x 10(6), 3 x 10(7) conidia/ml) of Beauveria bassiano (Balsamo) and Paecilomyces fumosoroseus (Wize) were tested on adults of C. capitata less than 3 days old. The flies were inoculated with spores by dipping them for 10-15 seconds in 10 ml of conidial suspension or water for control respectively. After that, flies were transferred to plastic cages with diet and water. There were 10 flies per cage and 4 replicates per concentration. Adults of the Mediterranean fruit fly, C. copitata, were high susceptible. In case of B. bassiana 100% of flies were dead at 3 x 10(7) conidia/ml and 82.5% at 3 x 10(6) conidia/ml. For P. fumosoroseus the mortality of flies was 70% at 3 x 10(7) conidia/ml and 62.5% at 3 x 10(7) conidia/ml. However, in low levels of concentration (3 x 10(4) and 3 x 10(5) conidia/ml respectively) only 7.5% and 30% flies died. Mouldiness of the dead flies ranged from 77.5% to 72.5% for the two higher concentrations (3 x 10(7) and 3 x 10(6) conidia/mt) of B. bassiona and 52.5% for P. fumosoroseus at 3 x l0(7) conidia/ml. The fungal mycelium of both entomopathogenic fungi emerged through the soft parts of the exoskeleton, such as the wing bases, legs bases, head and membranous regions of the abdomen. In case of B. bassiana additional the ovipositor was mouldy.
Ali
All
A
Humboldt Universität zu Berlin, Institute for Horticultural Sciences Department of Phytomedicine, Lentzeallee 55-57, DE-14195 Berlin, Germany.
Sermann
Helga
H
Büttner
Carmen
C
D000818:Animals; D033622:Ceratitis capitata / Q000254:growth & development / Q000382:microbiology*; D005658:Fungi / Q000472:pathogenicity*; D007928:Lethal Dose 50; D010143:Paecilomyces / Q000472:pathogenicity; D010572:Pest Control, Biological / Q000379:methods*; D011679:Pupa / Q000382:microbiology