Location: Crop Bioprotection ResearchTitle: Virulence of some entomopathogenic fungi isolates of Beauveria bassiana (Hypocreales:Cordycipitaceae) and Metarhizium anisopliae (Hypocreales:Clavicipitaceae) to Aulacaspis tubercularis and Icerya seychellarum on mango crop
|SAYED, ATEF - Agricultural Research Center Of Egypt|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/6/2019
Publication Date: 12/1/2019
Citation: Sayed, A.M.M., Dunlap, C.A. 2019. Virulence of some entomopathogenic fungi isolates of Beauveria bassiana (Hypocreales:Cordycipitaceae) and Metarhizium anisopliae (Hypocreales:Clavicipitaceae) to Aulacaspis tubercularis (Hemiptera:Diaspididae) and Icerya seychellarum (Hemiptera:Monophlebidae) on mango crop. Journal of Economic Entomology. 112(6):2584-2596. https://doi.org/10.1093/jee/toz187.
Interpretive Summary: An ARS researcher from Peoria, IL collaborated with an Egyptian scientist from the Ismailia Agricultural Research Station to characterize the susceptibility of insect pests of mango to common fungi that kill insects. The insects were the white mango scale and the Seychelles fluted scale, which are economically the most important insect pests of mango in Eygpt. The study discovered that both insect-killing fungi were effective in controlling the insects in lab and field assays. The study shows under certain condition natural fungi can very effectively control insects pests. Understanding the environmental and ecological conditions that allowed the disease to progress will improve the use of microbial biological control agents in integrated pest management systems. This research benefits U.S. farmers and consumers that rely on crops impacted by insect pests.
Technical Abstract: Six fungal isolates of Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) and one isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) were isolated and evaluated for their pathogenicity to Icerya seychellarum (Hemiptera:Monophlebidae) and Aulacaspis tubercularis (Hemptera:Diaspididae). There is a positive correlation between the concentration of the fungal blastospore concentrations and the percentage of mortality. Bio-efficacy increased significantly after inoculation with increasing concentration of blastospores and elapsed time up to 12 days after inoculation. The mortality of nymphs exposed to fungal isolates at various concentrations varied between 2.5 and 88.8%. Probit analysis of data at 95% confidence limits of LC50 and LT50s showed significant differences in the susceptibility of nymphs of I. seychellarum and A. tubercularis to the tested fungal isolates. The fungal isolates of Egy-6 and Egy-9 were the most effective against I. seychellarum and A. tubercularis, respectively. They had the lowest LC50 (4.20 x 10**5 and 5.71 x 10**3 blastospore mL**-1) and LT50 (ranged from 4.61 to 9.79 and 4.84 to 8.71 days), respectively. The current study showed that all the fungal isolates yielded moderate mortality rates of nymphs and adult female populations of both the tested insect pests. To our knowledge, this is the first report of bioefficacy of Beauveria and Metarhizium isolates against members of the Diaspidadae and Monophlebidae family insects. These results establish that the use of these native entomopathogenic fungi isolates of B. bassiana (Egy-3, Egy-4, Egy-6, Egy-7, Egy-9 and Egy-10) and M. anisopliae (Egy-5) could be considered for further development as microbial control agents of the mealybug and scale insects as a potential biological agent for use in an IPM program.