Clover Cutworm vs cobweb spiders

Anarta trifolii compared with Steatoda grossa

Taxonomic Classification

Rank	Clover Cutworm	cobweb spiders
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Arthropoda (Arthropods)	Arthropoda (Arthropods)
Class	Insecta (Insects)	Arachnida (Arachnids)
Order	Lepidoptera (Butterflies & Moths)	Araneae (Araneae)
Family	Noctuidae	Theridiidae
Genus	Anarta	Steatoda
Species	Anarta trifolii	Steatoda grossa

Evolutionary Relationship

Clover Cutworm and cobweb spiders share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Clover Cutworm

LC — Least Concern

cobweb spiders

LC — Least Concern

Physical Characteristics

Attribute	Clover Cutworm	cobweb spiders
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clover Cutworm

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).

cobweb spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Europe (29 countries), North America (Canada, United States), and South America (Ecuador).

Clover Cutworm

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.

cobweb spiders

The false black widow (Steatoda grossa) is a cosmopolitan cobweb spider in the family Theridiidae, often mistaken for the true black widow due to its similarly dark, globose abdomen, though it lacks the red hourglass marking. Females reach 6–10 millimeters in body length and display a deep purplish-brown to nearly black coloration with faint pale markings on the dorsal abdomen. Originally native to western Europe, Steatoda grossa has spread globally through human commerce, establishing populations in Australia, New Zealand, North America, and other regions where it thrives in human structures including homes, sheds, and outbuildings. The spider constructs a persistent, tangled cobweb in sheltered corners and recesses, where it captures woodlice, ants, beetles, and other arthropods—notably targeting invertebrates that many other spiders avoid. The venom of S. grossa causes steatodism, a syndrome of localized pain, sweating, and systemic discomfort that is rarely serious but can cause significant distress. Interestingly, the antivenin produced for Latrodectus (true widow) spider bites has been shown to effectively treat Steatoda envenomations, underscoring the phylogenetic relatedness of these genera. Females produce several egg sacs during a season, each containing dozens of eggs wrapped in distinctive silken cocoons. The species is classified as Least Concern given its expanding global distribution facilitated by human activity.

Shared Countries

Both species can be found in 5 countries:

🇧🇪 Belgium 🇨🇦 Canada 🇩🇰 Denmark 🇸🇪 Sweden 🇺🇸 United States