''Paenibacillus popilliae'' (formerly ''Bacillus popilliae'') is a soil-dwelling,
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
The Gram stain is ...
,
rod-shaped
Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archae ...
bacterium
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the ...
. It is responsible for a disease (commonly called milky spore) of the white grubs of
Japanese beetle
The Japanese beetle (''Popillia japonica'') is a species of Scarabaeidae, scarab beetle. Due to the presence of Predation, natural predators, the Japanese beetle is not considered a pest in its native Japan, but in North America and some region ...
s.
The adult Japanese beetles
pupa
A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...
te in July (in the Northeast United States) and feed on flowers and leaves of shrubs and garden plants. During this adult stage, the beetles also mate and the females lay eggs in the soil in late July to early August. The eggs hatch soon afterwards and in this
larva
A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...
l or grub stage, they feed on the roots of grass and other plants. As the weather gets cooler and winter approaches, the grubs go deeper into the soil, and feeding declines as they over-winter.
In August, when the grubs are close to the surface and feeding, they are vulnerable to infestation by milky spore. This is also the optimal time frame for turf inoculation or applications with milky spore to increase milky spore in the soil environment (there are product specific guidelines that should be followed for milky spore application).
Resident spores in the
soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...
are swallowed by grubs during their normal pattern of feeding on roots. This ingestion of the spore by the host activates reproduction of the bacteria inside the grub. Within 7–21 days the grub will eventually die and as the grub decomposes, billions of new spores are released into the soil.
Milky spore in the soil is not harmful to beneficial insects, birds, bees, pets, or people; and milky spore, like other bacteria, is highly survivable in drought conditions but suffers in temperatures of
Zone
Zone, Zones or The Zone may refer to:
Places Military zones
* Zone, any of the divisions of France during the World War II German occupation
* Zone, any of the divisions of Germany during the post-World War II Allied occupation
* Korean Demilit ...
5 and colder.
See also
*''
Bacillus lentimorbus''
Sources
*
Milkyspore.com
External links
Type strain of ''Paenibacillus popilliae'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6858158, from2=Q62872792
Paenibacillaceae
Biological control agents of pest insects
Bacteria described in 1941