**Woodlice** (Order Isopoda, terrestrial crustaceans, e.g., **Pillbugs** or **Sowbugs**) are common arthropods found in dark, damp environments. The conflict is **nuisance and occasional seedling damage**: they primarily feed on decaying organic matter (beneficial to soil), but when populations are high or conditions are excessively wet, they may chew on the tender leaves, stems, and roots of young **seedlings** and ripe strawberries, moving from a beneficial role to a minor garden pest.
Taxonomy and Classification
Woodlice belong to the Phylum Arthropoda, Class Malacostraca, making them the only terrestrial crustacean. They undergo simple metamorphosis (direct development).
Physical Description
Adults are $5\text{ mm}$ to $15\text{ mm}$ long.
- **Appearance (Key ID):** Oval, segmented, gray or brownish body; seven pairs of legs; **Pillbugs** (*Armadillidium* spp.) can roll into a protective ball; **Sowbugs** (*Porcellio* spp.) cannot and have two rear appendages (**uropods**).
- **Behavior ID:** Entirely nocturnal; require high humidity to breathe and survive; often clustered under pots, rocks, or mulch during the day.
- **Conflict:** Nuisance, Minor Agricultural.
Distribution and Habitat
Cosmopolitan, found worldwide. Habitat is any location with consistent moisture and decaying matter: under stones, in mulch, compost piles, and accidentally indoors in damp basements or crawl spaces.
Behavior and Conflict
The conflict is driven by their moisture dependency and population density.
- **Entry:** They enter structures only when humidity is extremely high or when seeking refuge from drying outdoor conditions.
- **Primary Decomposers:** In the garden, their primary role is beneficial—breaking down organic matter and recycling nutrients.
Management and Prevention
Management is **Moisture Reduction and Exclusion**.
- **Reducing Moisture:** Fixing leaky pipes, improving drainage, and increasing ventilation in basements and crawl spaces.
- **Reducing Food/Shelter:** Removing leaf litter, heavy mulch, and debris close to foundations.
- Sealing foundation cracks and window gaps to prevent accidental indoor entry.
Conservation and Research
Research focuses on their unique physiology as land-dwelling crustaceans and their role in soil ecology and decomposition processes.