Ornamental and Turf Pesticide Applicators Practice Exam

What is the primary target of the milky spore bacterium?

1. All types of beetle grubs

2. Japanese beetle grubs

3. Fire ants

4. Mole crickets

The correct answer is: Japanese beetle grubs

The milky spore bacterium primarily targets Japanese beetle grubs, which are the larvae of the Japanese beetle (Popillia japonica). This bacterium, scientifically known as Bacillus popilliae, is specifically effective against this pest. When the bacterium is applied to the soil, it can infect and kill the grubs, thus controlling their population. The specificity of the milky spore bacterium means it is not effective against other types of beetle grubs or pests such as fire ants or mole crickets, which are not its intended targets. Consequently, while the milky spore can significantly reduce Japanese beetle grub populations, its action does not extend to other insect pests, emphasizing the importance of knowing the specific targets when using biological control agents like milky spore.