Black Cutworm vs Cobweb Spiders

Agrotis ipsilon compared with Parasteatoda tepidariorum

Taxonomic Classification

Rank	Black 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	Agrotis	Parasteatoda
Species	Agrotis ipsilon	Parasteatoda tepidariorum

Evolutionary Relationship

Black Cutworm and Cobweb Spiders share a common ancestor at the Phylum level: Arthropoda. (Arthropods)

Conservation Status

Black Cutworm

LC — Least Concern

Cobweb Spiders

LC — Least Concern

Physical Characteristics

Attribute	Black Cutworm	Cobweb Spiders
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black Cutworm

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 6 distinct biome types spanning the Afrotropic and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (7 countries), Asia (Taiwan), Europe (5 countries), North America (Canada, United States), and South America (Chile).

Cobweb Spiders

Habitat

Typically found in terrestrial habitats from forests to deserts.

Range

Widely distributed across Africa (South Africa), Asia (Taiwan), Europe (7 countries), North America (Canada, United States), and South America (Colombia).

Black Cutworm

The Black Cutworm (Agrotis ipsilon) is a species in the genus Agrotis. It is currently classified as Least Concern on the IUCN Red List. Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 6 distinct biome types spanning the. Widely distributed across Africa (7 countries), Asia (Taiwan), Europe (5 countries), North America (Canada, United Stat...

Cobweb Spiders

The common house spider (Parasteatoda tepidariorum) is one of the most cosmopolitan of all spider species, having followed human civilization to virtually every inhabited corner of the globe. A member of the family Theridiidae, this small to medium-sized spider—females reaching 5–8 millimeters, males somewhat smaller—constructs the characteristic messy, three-dimensional cobwebs in sheltered corners of buildings, under eaves, in cellars, and in other human-modified structures worldwide. Originally native to North and South America, the species has spread through commerce and human transport to Europe, Asia, Africa, and beyond, where it thrives in the stable temperature and prey-rich conditions provided by human habitation. The web design is deceptively effective: irregular sticky threads radiate in all directions from a silk retreat, ensnaring flies, mosquitoes, ants, and other arthropods that blunder into the structure. Females are long-lived—surviving several years—and produce multiple egg sacs containing hundreds of eggs during a lifetime, contributing to the species' population resilience. Parasteatoda tepidariorum has become an important laboratory model organism for arachnid developmental biology, with its genome sequenced to facilitate studies of spider gene expression, venom evolution, and silk production. It is broadly classified as Least Concern given its cosmopolitan distribution and remarkable adaptation to anthropogenic environments.

Shared Countries

Both species can be found in 9 countries:

🇧🇪 Belgium 🇨🇦 Canada 🇩🇰 Denmark 🇳🇴 Norway 🇵🇹 Portugal 🇿🇦 South Africa 🇸🇪 Sweden 🇹🇼 Taiwan 🇺🇸 United States