گزارش جداسازی قارچ Fusarium acuminatum Ellis & Everh. از لارو شب‌پره برگخوار سفید بلوط، Leucoma wiltshirei Coll. (Lepidoptera: Erebidae)

The Oak, one of the most important tree species in Iran's forests, which accounts for about 55% of the country's forests, has been subjected to severe damage by the oak moth (Leucoma wiltshirei Coll. 1938). This moth is one of the most important pests of oak trees because it has multiple generations, has high laying potential, is resistant to harsh microclimatic conditions and has a scavenging (oak leaves) diet. In order to find natural biological control agents and use them against the mentioned pest, the oak forests of Fars province were visited and sampled. The deformed or discolored larvae were collected, after surface disinfection with 5% sodium hypochlorite for 1 minute, 96% ethanol for 1 minute and washing three times with sterile distilled water, they were dried on filter paper and then incubated in PDA culture medium and temperature of 25 degrees. After 5 days, a pure culture was prepared from the resulting fungal colony. Colony characteristics (color, growth rate), micro and macro conidia properties, shape and size of the conidia carriers were examined under the light microscope. DNA extraction from the mycelium of a 7-day fungus culture was carried out using the CTAB method and using the ITS1F and ITS4 primers. The fungal colony has aerial mycelium, red to orange pigment in the center and reaches a size of 90 mm after 5 days at 25 degrees. Macroconidia 4-5 cells, microconidia were not observed. The results of sequence blast analysis showed that it has 99% similarity to Fusarium acuminatum Ellis & Everh. (1895) isolates from the GenBank and is registered in the NCBI database with accession code PP894313. Many Fusarium lineages have been reported to be efficient in controlling insects and to exhibit promising characteristics for agricultural and natural resources pest control such as causing high mortality rates in larvae and adult, having fast action and abundant sporulation. At least 30 species and 273 isolates of Fusarium were reported as pathogenic to at least one species of insect. There are reports of the isolation and pathogenicity of F. acuminatum in some insects such as the wheat stem fly and the wood-eating beetle. This report is the first case of isolation of this fungus from the white oak moth.