Allomyrina dichotoma is a typical pet beetles in Korea. From 2010, similar symptoms of milky spore disease were found collectively in grubs of the species reared in insect farms. They shared a specific symptom that the skin of last instar larvae was changed softer with opaque white and infested grubs eventually died. To clarify the cause of the symptom, we collected the larvae of A. dichotoma from five farms and examined intestinal bacterial florae of them using pyrosequencing technique. From those results, a member of Paenibacillus was found only in the larvae showing the symptom of disease. Through PCR analysis using a Paenibacillus specific primer set, we obtained the partial 16S rRNA gene sequence and confirmed the microbe as Paenibacillus sp. For detailed characterizing, a whole guts was extracted from each larva showing the sign of the disease and incubated at 70℃ for 15 min to isolate spore forming bacteria. After then, each content of guts was cultured on MYPGPNAL agar medium (12.5 μg/ml of nalidixic acid) at 30℃. The 16S rRNA gene sequence analysis for six isolate showed that they were closely related to P. rigui (97.5~98.0% similarity) and to P. chinjuensis (95.9~96.6% similarity). Additional tests including API test and cellular fatty acid composition analysis were performed, but the strain couldn’t be identified at species level, suggesting it may represent novel species of the genus Paenibacillus.

Two species entomopathogenic fungi most widely used and valued in traditional Asian medical practice are Ophiocordyceps sinensis (formely Cordyceps sinensis) and Cordyceps militaris. Although O. sinensis may be the more famous and expensive fungus, it is also comparatively rare and cannot be grown or made to fruit readily in culture whereas C. militaris occurs worldwide, can be easily cultured, and is the easist of all Cordyceps species to fruit in culture. There is a well establihed cottage industry in Korea to produce C. militaris as a dietary supplement or even as a culinary ingredient used to promote improved health. Most of the Korean farmers raising C. militaris obtain fruiting bodies from silkworms that are injected with suspensions of hyphal bodies grown in liquid cultures. This study seeks to facilitate and to simplify the injection process used to produced this fungus by finding a simple cullture medium on which abundant supplies of the Lecanicillium conodial state of C. militaris are produced and can be used with simplified injection protocols involving spraying or dipping in conidial suspensions than the more material- and labor- intensive injection protocol. The studies to be repored include quantitative tests of conodial yields on varying carbon sources, varying nitrogen sources, and attempted to optimize the carbon/nitrogen ratio and pH of the medium for conidial production.