Spoladea

Guenée, 1854

beet webworm, Hawaiian beet webworm, amaranth leaf-webber

Spoladea is a of Crambidae containing two described , with S. recurvalis being a significant agricultural pest of amaranth, spinach, and sugar beet across tropical and subtropical regions worldwide. The genus was established by Guenée in 1854. S. recurvalis has achieved nearly distribution through human-mediated and is subject to intensive study for molecular mechanisms of production, , and interactions to support .

Spoladea by (c) Thomas Boe, some rights reserved (CC BY), uploaded by Thomas Boe. Used under a CC-BY license.

Spoladea recurvalis by (c) Hsu Hong Lin, some rights reserved (CC BY). Used under a CC-BY license.

Pronunciation

How to pronounce Spoladea: //spɒlˈɑːdiə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

-level identification requires examination of pattern and ; S. recurvalis can be distinguished by pattern with a distinct whitish curving from to , creating a characteristic '' appearance referenced in the specific epithet. produce webbing on foliage. S. mimetica is restricted to the Neotropics and differs in genital .

Images

Habitat

Associated with cultivated and wild Amaranthus in agricultural and disturbed ; occurs in tropical and subtropical lowlands where plants are available.

Distribution

Pantropical and subtropical distribution with extension into temperate regions; S. recurvalis documented across Africa, Asia, Australasia, Pacific Islands, North America (southeastern USA), Central America, Caribbean, and South America. Recently expanding in Europe with records from Italy and other Mediterranean countries.

Diet

feed on foliage of Amaranthus (primary ), with additional records from spinach (Spinacia oleracea) and sugar beet (Beta vulgaris). require nectar feeding for survival and sustained activity.

Host Associations

Amaranthus - primary Main for larval development; multiple accessions show varying levels
Spinacia oleracea - Spinach; significant agricultural pest
Beta vulgaris - Sugar beet; 'beet ' origin

Life Cycle

with , larval, pupal, and stages. Female S. recurvalis have a 3-day pre- period and continue egg-laying for up to 20 days post-. Larval development occurs within webbed foliage on plants.

Behavior

females exhibit highest activity during the pre- period. Flight performance is temperature-dependent with optimal range of 17–23°C; approximately 10% of females capable of sustained long-duration flight at 12°C. Adult feeding on nectar is essential for survival—deprivation of solution for even one day significantly depresses subsequent flight activity.

Ecological Role

and agricultural pest; serves as for larval Apanteles hemara, which is the in African and Asian and has been studied for .

Human Relevance

Major pest of leafy vegetables and root in tropics and subtropics; causes complete foliage loss under severe . Subject of transcriptome sequencing for development of novel pest management strategies including -based control. Expanding distribution in Europe monitored through citizen science platforms.

Similar Taxa

HymeniaFormerly included S. recurvalis as Hymenia recurvalis; distinguished by genitalic and characters placing Spoladea in Spilomelinae
Other Crambidae webwormsLarval webbing shared with many Spilomelinae; identification requires genital dissection and pattern analysis