Mae’r oedolion yn hedfan yn agos i’r ddaear, gan aros yn aml i gymryd neithdar o flodau megis Mieri ac Ysgall. Gellir gwahaniaethu rhyngddi a’r Fritheg Berlog ar sail y perlau gwynnaidd mwy niferus sydd ar du isaf yr adennydd cefn, y sieffrynau duon sydd o gwmpas y perlau allanol, a’r smotyn canolig du sy’n fwy o faint.
Erys y glöyn byw yma’n eang ei ddosbarthiad ac yn niferus mewn mannau yn yr Alban a Chymru, ond mae ei niferoedd wedi gostwng yn arw yn Lloegr.
Gwelir y glöyn byw mawr grymus hwn fel rheol yn hedfan yn chwim uwchben y rhedyn neu’r tyfiant isel mewn llennyrch yn y coed. Tra’u bod yn hedfan mae hi bron yn amhosibl gwahaniaethu rhwng gwrywod y rhywogaeth hon a rhai’r Fritheg Werdd, sydd yn aml yn cydrannu’r un cynefinoedd. Ond mae’r ddwy rywogaeth yn ymweld yn aml â blodau megis Ysgall a Mieri, lle mae’n bosibl gweld y marciau gwahaniaethol ar du isaf yr adennydd. Nid oes gan y Fritheg Werdd y ‘perlau’ â chylch lliw oren o’u cwmpas sydd ar du isaf adenydd cefn y Fritheg Frown.
A migrant species that can sometimes arrive in large influxes with other migrants.
The Rusty Dot Pearl has multiple generations each year, usually spending winter as a pupa in the soil.
Caterpillars can reach a length of 10–15 millimetres (0.39–0.59 in. The adult moth flies at night and is attracted to light.
Flight Times
Primarily a migrant species to the UK but can be found at almost any time of the year.
Size and Family
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Family – Crambidae
-
Small Sized
One of our more common winter moths, especially during mild spells, and can be found feeding at sallow blossom in early spring
Flight Season
Flies from September through to May.
Size and Family
- Family – Noctuidae
- Small Sized
- Wingspan Range – 28-36mm
Conservation status
- UK BAP: Not listed
- Common
Caterpillar Food Plants
Caterpillars feed on the foliage of a range of trees, including birch (Betula) and oak (Quercus).
A variable species but most often encountered as a reddish-brown ground colour with white or orange reniform stigmata. The small 'satellites' either side of the stigma can be obscure, especially in worn individuals.
Adult moths are attracted to sugar and light.
Flight Season
Flies from September through to April in one generation.
Flies from dusk into the night when it is attracted to light.
Flight Season
Flies from June and July, and again in August and September in two generations.
Size and Family
- Family – Erebidae
- Small Sized
- Wingspan Range – 18-22mm
Conservation status
- UK BAP: Not listed
- Relatively common
Caterpillar Food Plants
Caterpillars feed on various grasses
Habitat
Damp meadows and woodland
Not found in the UK.
Size and Family
- Family: Nymphalids
- Size: Medium
- Wing Span Range (male to female): 35-55mm
Conservation Status
- Butterfly Conservation priority: Low
- European Status: Not threatened
Caterpillar Foodplants
Caterpillars feed on leaves of the Nettle-tree (Celtis australis)
Habitat
Open light woodland but also shrubs and even urban places
Not found in the UK.
Size and Family
- Family: Nymphalids
- Size: Large
- Wing Span Range (male to female): 65-90mm
Conservation Status
- Butterfly Conservation priority: Low
- European Status: Not threatened
Caterpillar Foodplants
Caterpillars feed on leaves of the Strawberry tree (Arbutus unedo)
Habitat
Wooded hillsides with plenty of foodplant but can sometimes be found in town centres.
Not found in the UK. Adults fly in a single brood from late May through to August. Winter is spent as an egg or young caterpillar.
Size and Family
- Family: Nymphalids / Fritillaries
- Size: Medium
- Wing Span Range (male to female): 30-44mm
Conservation Status
- Butterfly Conservation priority: Low
- European Status: Not threatened
Caterpillar Foodplants
Caterpillars feed on Bramble.
Not found in the UK.
Overwinters as a caterpillar.
Size and Family
- Family: Blues & Hairstreaks
- Size: Small
- Wing Span Range (male to female): 20-30mm
Conservation Status
- Butterfly Conservation priority: Low
- European Status: Not threatened
Caterpillar Foodplants
Caterpillars feed on Common Bird's-foot-trefoil and Gorse.
Habitat
Grassy, flowery places such as Meadows, farmland and wasteland.