The Rivulet
Perizoma affinitata
This record describes Perizoma affinitata (species). Recorded family: Geometridae. Recorded order: Lepidoptera.
Identification and Appearance
Wingspan 24 to 30 mm. Similar to the Small Rivulet (Perizoma alchemillata) but noticeably larger. Occupying woodland margins, hedgerows and grassy embankments. The main flight period is between May and July, when it is often attracted to light. Red Campion (Silene dioica) is the preferred foodplant, the caterpillars living inside the seed capsules, eating the seeds. A widely distributed species in Britain, but local in northern Scotland and Ireland. In a recent survey to determine the status of all macro moths in Britain this species was classified as common.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Lepidoptera
- Family
- Geometridae
- Genus
- Perizoma
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
Occupying woodland margins, hedgerows and grassy embankments.
Seasonal Activity
The main flight period is between May and July, when it is often attracted to light.
Diet and Behavior
Life History
Red Campion (Silene dioica) is the preferred foodplant, the caterpillars living inside the seed capsules, eating the seeds.
Additional species information
Recorded status
A widely distributed species in Britain, but local in northern Scotland and Ireland. In a recent survey to determine the status of all macro moths in Britain this species was classified as common.
About Butterflies and Moths: the wider group
Order-level background for Lepidoptera, the group containing Perizoma affinitata. Species-specific details appear above.
Group overview
Lepidoptera includes approximately 180,000 described species of butterflies and moths. Moths outnumber butterflies roughly 10:1. The monarch butterfly's eastern population has declined by more than 80% since the mid-1990s, and the western population by over 95% since the 1980s. The IUCN lists the migratory monarch as Vulnerable.
Ecological role of the group
Butterflies and moths are essential indicators of ecosystem health. As caterpillars, they are a primary food source for birds - a single nest of blue tit chicks requires ~10,000 caterpillars. Adult moths pollinate many night-blooming plants.
Economic and practical significance of the group
Lepidoptera are critical pollinators. In Europe, grassland butterfly species have declined by almost 50% since the early 1990s. In the UK, three-quarters of butterflies are in decline. In the U.S., five butterfly species have gone extinct since 1950, with 29 listed as endangered.
Recorded sources for this group: IUCN Red List, Xerces Society, USFWS, PNAS, WWF. Imported estimates may describe particular regions or reporting periods.
Photos of The Rivulet (7)
Frequently Asked Questions About The Rivulet
What is The Rivulet?
The Rivulet (Perizoma affinitata) is a species in the family Geometridae, within the order Lepidoptera.
Where is The Rivulet found?
Habitat: Occupying woodland margins, hedgerows and grassy embankments.
When is The Rivulet active?
The Rivulet: seasonal activity - The main flight period is between May and July, when it is often attracted to light..
What is the life cycle of a The Rivulet?
Red Campion (Silene dioica) is the preferred foodplant, the caterpillars living inside the seed capsules, eating the seeds.