Common Spangle Gall vs Compact Thread-leaf Century Plant

Neuroterus quercusbaccarum compared with Agave microceps

Key Differences

• Common Spangle Gall is Not Evaluated while Compact Thread-leaf Century Plant is Least Concern.

Taxonomic Classification

Rank	Common Spangle Gall	Compact Thread-leaf Century Plant
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Magnoliophyta (Flowering Plants)
Class	Insecta (Insects)	Liliopsida (Monocots)
Order	Hymenoptera (Ants, Bees & Wasps)	Asparagales (Asparagales)
Family	Cynipidae	Asparagaceae
Genus	Neuroterus	Agave
Species	Neuroterus quercusbaccarum	Agave microceps

Conservation Status

Common Spangle Gall

NE — Not Evaluated

Compact Thread-leaf Century Plant

LC — Least Concern

Physical Characteristics

Attribute	Common Spangle Gall	Compact Thread-leaf Century Plant
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Spangle Gall

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

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

Compact Thread-leaf Century Plant

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

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.

Compact Thread-leaf Century Plant

<em>Agave microceps</em>, the compact thread-leaf century plant, is a perennial succulent in the family Asparagaceae native to Mexico, representing one of the smaller members of the ecologically and culturally significant agave genus. Agaves are iconic succulents of arid and semi-arid regions characterised by a rosette of thick, fibrous leaves typically edged with teeth and terminating in a sharp spine. <em>Agave microceps</em> typically forms compact, densely-leaved rosettes with notably narrow, thread-margined leaves, distinguishing it from larger agave species. It inhabits rocky slopes, dry grasslands, and scrublands in its native Mexican range, adapted to well-drained soils and periods of seasonal drought. Like all agaves, it is monocarpic, flowering once after many years of vegetative growth before dying, producing a tall flower spike that provides food resources for bats, hummingbirds, and insects. The species is classified as Least Concern by the IUCN, indicating a stable population without critical current threats, though many agave species face pressure from illegal collection for the horticultural trade and habitat conversion. Agaves play important roles in native ecosystems as food sources for specialist pollinators and as habitat elements on rocky hillsides. Biological traits including average lifespan in the wild, precise rosette dimensions, and population data remain poorly documented for this species compared to more commercially important agaves.