Common Fieldcap vs Common Spangle Gall

Agrocybe pediades compared with Neuroterus quercusbaccarum

Key Differences

• Common Fieldcap is Least Concern while Common Spangle Gall is Not Evaluated.

Taxonomic Classification

Rank	Common Fieldcap	Common Spangle Gall
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Basidiomycota (Club Fungi)	Arthropoda (Arthropods)
Class	Agaricomycetes (Mushrooms)	Insecta (Insects)
Order	Agaricales (Gilled Mushrooms)	Hymenoptera (Ants, Bees & Wasps)
Family	Strophariaceae	Cynipidae
Genus	Agrocybe	Neuroterus
Species	Agrocybe pediades	Neuroterus quercusbaccarum

Conservation Status

Common Fieldcap

LC — Least Concern

Common Spangle Gall

NE — Not Evaluated

Physical Characteristics

Attribute	Common Fieldcap	Common Spangle Gall
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Fieldcap

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Found across Europe (5 countries) and North America (United States).

Common Spangle Gall

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Distributed across Belgium, Denmark, Norway, Sweden, and United States.

Common Fieldcap

The Common Fieldcap (<em>Agrocybe pediades</em>) is a saprotrophic fungus belonging to the genus Agrocybe within the family Strophariaceae. It typically produces small, tan to pale brown cap-shaped fruiting bodies and is often found growing in clusters or scattered on lawns, grassy areas, forest floors, decomposing wood, and soil-rich ecosystems. The species typically inhabits forest floors, decomposing wood, and soil ecosystems, obtaining nutrients by breaking down dead organic matter. Its geographic range includes several European countries — Belgium, Denmark, Norway, Portugal, and Sweden — as well as the United States in North America. <em>Agrocybe pediades</em> is assessed as Least Concern on the IUCN Red List, reflecting its broad distribution and apparent stability. Biological traits of this species, including specific data on fruiting body size, lifespan, and ecological preferences, remain poorly documented in the scientific literature. Like other members of its genus, it typically fruits during warmer months and often appears after rainfall in nutrient-rich grassland and woodland habitats.

Common Spangle Gall

<em>Neuroterus quercusbaccarum</em>, commonly known as the common spangle gall, is a small gall wasp in the family Cynipidae, closely associated with oaks in Europe and western Asia. This species is notable for its complex life cycle involving alternating sexual and asexual generations, each producing morphologically distinct galls on its oak hosts. The asexual generation typically induces flat, disc-shaped "spangle" galls on the undersides of oak leaves, while the sexual generation produces small "currant" galls on oak catkins and leaves in spring. <em>Neuroterus quercusbaccarum</em> is widely distributed across Europe, extending into parts of western Asia and North Africa wherever suitable oak hosts, particularly <em>Quercus robur</em> and <em>Quercus petraea</em>, occur. The species has not been evaluated under IUCN Red List criteria, and population trends are not formally monitored, though it remains common across much of its range. Biological traits such as average lifespan in years, body dimensions, and weight remain poorly documented in the scientific literature for this minute insect. The larvae develop entirely within gall tissue, feeding on plant nutrients provided by the gall structure they induce. Adult wasps are free-living and do not feed substantially. Conservation status is listed as Not Evaluated.

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States