ver-gris du trèfle vs Common Knotweed

Anarta trifolii compared with Polygonum arenastrum

Key Differences

ver-gris du trèfle is Least Concern while Common Knotweed is Not Evaluated.

Taxonomic Classification

Rank	ver-gris du trèfle	Common Knotweed
Kingdom	Animalia (animal)	Plantae (plante)
Phylum	Arthropoda (arthropodes)	Magnoliophyta (Flowering Plants)
Class	Insecta (insecte)	Magnoliopsida (Dicots)
Order	Lepidoptera (Butterflies & Moths)	Caryophyllales (Caryophyllales)
Family	Noctuidae	Polygonaceae
Genus	Anarta	Polygonum
Species	Anarta trifolii	Polygonum arenastrum

Conservation Status

ver-gris du trèfle

LC — Least Concern

Common Knotweed

NE — Not Evaluated

Physical Characteristics

Attribute	ver-gris du trèfle	Common Knotweed
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

ver-gris du trèfle

Habitat

Inhabits tropical and subtropical dry broadleaf forests and deserts and xeric shrublands within the Afrotropic biogeographic realm.

Range

Widely distributed across Africa (Cabo Verde), Asia (Yemen), Europe (4 countries), and North America (Canada, United States).

Common Knotweed

Habitat

Typically found in diverse terrestrial habitats from tropical forests to temperate regions.

Range

Widely distributed across Asia (Taiwan), Europe (10 countries), and North America (Mexico, United States).

ver-gris du trèfle

The clover cutworm (Anarta trifolii) is a noctuid moth in the family Noctuidae, order Lepidoptera, with a wide distribution spanning Europe, Asia, Africa, and North America. The species has a characteristic cutworm larva that severs plant stems near the soil surface or feeds on leaves and developing seeds, causing significant damage to crops. Primary host plants include clover (Trifolium), alfalfa, beet, and various other broadleaf crops and weeds, making A. trifolii an agricultural pest of moderate to significant importance in affected regions. Adults are brownish-grey moths with subtle wing patterns typical of the noctuidae family, and like most noctuids, they are nocturnal and attracted to light sources. The species is highly mobile, with adults capable of long-distance migration that enables rapid colonization of new agricultural areas. A. trifolii inhabits a broad range of open habitats including agricultural fields, meadows, steppes, and disturbed grasslands across its extensive range. Its polyphagous larval diet and migratory adult behavior contribute to its wide geographic range spanning multiple continents. In Europe, it is found from the Mediterranean to Scandinavia; in North America it occurs in both Canada and the United States. A. trifolii is classified as Least Concern on the IUCN Red List, with populations considered stable and the species benefiting from the widespread availability of agricultural host plants. Natural enemies include parasitoid wasps and tachinid flies, along with pathogens including nuclear polyhedrosis viruses used in biological control.

Common Knotweed

Common Knotweed (<em>Polygonum arenastrum</em>) is a prostrate annual herb in the family Polygonaceae, distributed across Asia, Europe, and North America. Its native range encompasses Taiwan in Asia, ten European countries, and Mexico and the United States in North America. The species typically colonizes highly disturbed, compacted substrates such as footpaths, roadsides, cultivated ground, and waste places, exhibiting a strong association with anthropogenic disturbance. Its wiry, branching stems and small, pale pink flowers form dense mats close to the ground, making it well adapted to trampled environments. The conservation status of this species has not been formally evaluated by the IUCN. As a cosmopolitan ruderal plant, it is broadly tolerant of environmental stress and contributes to ground cover in highly modified habitats throughout the temperate zone. Biological traits of this species remain poorly documented in the scientific literature.