Bug FAQSmall Square-spot
Diarsia rubi · Order: Lepidoptera · Family: Noctuidae
The small square-spot moth has a wingspan of about 30 to 38 mm and dull grey-pink forewings with a pale angular mark that gives it its name. It flies in two generations each year, first in May-June and again in August-September, and overwinters as a larva.
Source: Wikipedia
How to recognize it
Forewings show olive crosslines, a brown cell, a whitish-outlined reniform spot, a claviform spot ending in a dark speck, and a dark marginal area.
Source: Wikipedia
Size
Wingspan ranges from 30 to 38 mm, making it a relatively small moth.
Source: Wikipedia
What it eats
Caterpillars feed on plants such as raspberry, Vaccinium species and willow. Adults visit flowers like heather and ragwort for nectar.
Source: Wikipedia
Life cycle
Two broods are produced each year; adults are on the wing in May-June and again in August-September. The species overwinters in the larval stage.
Source: Wikipedia
When you see it
Adults appear in two periods: May-June and August-September.
Source: Wikipedia
Lookalikes
It can be hard to separate from close relatives such as Protolampra sobrina, Diarsia mendica (including subspecies mendica, thulei, orkneyensis) and Diarsia florida.
Source: Wikipedia
More photos
Questions people ask
When are small square-spot moths active?
Adults fly in two periods each year: May-June and August-September.
Source: Wikipedia
What do the larvae eat?
The caterpillars feed on raspberry, Vaccinium plants and willow.
Source: Wikipedia
Same family (Noctuidae)
Ipsilon Dart MothAgrotis ipsilonDamages trees, gardens or crops
Fall Armyworm MothSpodoptera frugiperdaDamages trees, gardens or crops
Army Cutworm MothEuxoa auxiliarisDamages trees, gardens or crops
Large Yellow UnderwingNoctua pronubaDamages trees, gardens or crops
Silver ΥAutographa gamma
American DaggerAcronicta americanaCan irritate skinSources
- Wikipedia: https://en.wikipedia.org/wiki/Small_square-spot
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-24 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.