A new insect pathogenic fungus from Entomophthorales with potential for psyllid control
Psyllid pest in fruit orchards can have major economic consequences as they often cause direct and indirect damage on the trees. Obligate entomopathogenic fungal species from the order Entomophthorales normally have a narrow host range and can cause natural epidemics and have by that a potential for biological control of psyllids. During late summer in 2016, live psyllids were collected from both apple and pear trees mainly in fruit orchards in North Zealand, Denmark, in order to discover natural infections by entomopathogenic fungi. The collected insects were incubated alive in the laboratory, and psyllids infected with Entomophthorales were for the first time documented. Infection was only found in Cacopsylla spp. collected from pear trees and only in one of the fruit orchards. Fungal isolates were successfully isolated and cultivated in vitro from four sporulating cadavers on Sabouraud dextrose agar-medium (SDA) supplemented with egg yolk and milk using the ‘ascending conidia’ showering method. Based on morphological characters of the conidia and DNA sequences of the ITS-region, the fungus proved to be a species from the genus Pandora (Entomophthorales: Entomophthoraceae). The pathogenicity of all strains of the isolated fungi was examined in the laboratory of the Julius- Kühn Institute (Dossenheim, Germany) on two different psyllid species (Cacopsylla pyri and Cacopsylla pyricola). The results showed that all strains were able to infect both species of psyllids. Our preliminary results indicate the potential of this Pandora sp. as a biological control agent of psyllids pest in fruit orchards.