Abstract

Simple SummaryCordyceps farinosais a widely distributed entomopathogenic fungus, which is highly infective and lethal toThitarodes armoricanuslarvae, thus it seriously endangers the Chinese cordyceps industry. Due to the lack of understanding of its infection process, there are currently no effective prevention and control strategies. In this study, we firstly obtained fluorescently labeledC. farinosamutants byAgrobacterium-mediated transformation to better observe the pathway ofC. farinosainfecting theT. armoricanuslarvae. We then used the fluorescentC. farinoseto infectT. armoricanuslarvae. The results showed that the infection routes were through the body surface and the digestive tract. Our findings lay the foundation for further research and control of this pathogenic fungus.AbstractCordyceps farinosais often utilized as a biocontrol agent because of its wide host range, strong lethality, and safety for mammals. Artificial rearing ofThitarodes armoricanuslarvae is a prerequisite for the artificial cultivation ofChinese cordyceps, andC. farinosais the most lethal pathogenic fungus during the rearing process. However, the infection process ofC. farinosais still unclear. In this study, we cloned the promoter of theC. farinosaglyceraldehyde 3-phosphate dehydrogenase gene, constructed the EGFP expression cassette, and integrated it into theC. farinosagenome viaAgrobacteriumtransformation. We obtained a fluorescent strain for better observation of the infection process. Using two different inoculation methods of the fluorescent strain, we observed the traditional infection process through the body surface as well as through the digestive tract via feeding. Both infection modes can lead to larval death and mummification. Our findings demonstrated that during the artificial rearing ofT. armoricanus, preventingC. farinosapollution should be an important part of the disinfection of the rearing environment.Keywords:Cordyceps farinosa;genetic transformation;Thitarodes arm