The frequency and time of the outbreak of insect diseases were investigated among the insect-rearing farms by regional groups. The purpose of this study was to predict the insect diseases and reduce the spread of diseases. From February to October 2016, 87 of diseased insects were collected in seven regions. It turned out that the pathogens for fungal diseases were identified as Metarhizium anisopliae. But in case of bacterial diseases, the pathogenicity of the bacteria isolated from the diseased insects were not confirmed. Bacterial diseases occurred mainly in June and August in Gyeonggi-do and Gangwon-do, while in Chungcheong-do, bacterial and viral disease raged. In Jeolla-do, both fungal and bacterial diseases occurred in June. Generally, bacterial diseases occurred mainly from June to October, while the frugal diseases occurred from January to March. It was concluded that the entomopathogenic fungi, Metarhizium anisopliae, tended to cause diseases during late-winter and early spring and bacteria, uncertain, was prone to cause diseases during summer. Therefore, it necessary to adequately control depending on the type of the entomopathogen.