The present invention provides a process for efficiently producing sporangia of Bacillus popilliae containing spores and parasporal bodies having controlling effects on Scarabaeidae insects, and a control agent and controlling method for Scarabaeidae insects obtained by said production process. In a process for producing sporangia of Bacillus popilliae containing spores and parasporal bodies by culturing Bacillus popilliae in a medium containing an adsorbent, the medium contains 0.2-4.0% by weight of glutamic acid.