Spoladea recurvalis

Distinguished from similar crambid moths by the characteristic recurved white markings on the forewings (the source of the specific epithet 'recurvalis'). The banded wing pattern with contrasting brown and white is distinctive. In Europe, distinguished from native species by its tropical origin and association with cultivated amaranth and beet crops. Molecular identification supported by transcriptome data showing highest sequence similarity to Danaus plexippus among reference databases.

Agricultural and horticultural environments, particularly where host plants (Amaranthus spp., Beta vulgaris, Spinacia oleracea) are cultivated. In tropical and subtropical native range, occurs in diverse agricultural settings. In expanded temperate range, associated with protected cultivation and urban gardens where host plants persist.

Native to tropical and subtropical regions worldwide. Documented from Africa, Asia, Australasia, Pacific Islands, and the Americas. Expanded distribution into Europe (first records in Italy with subsequent spread to multiple regions; also recorded in Belgium). In North America, established in southeastern USA (Florida, South Carolina, Virginia, New Jersey). Present on oceanic islands including Hawaii, Galápagos, and Atlantic islands. Range expansion ongoing, facilitated by human transport of host plants and climate change.

Adult flight period varies geographically: May to September in temperate regions, year-round activity in tropics. In laboratory conditions, females exhibit pre-oviposition period of 3 days and continue egg-laying for up to 20 days post-emergence. Temperature strongly influences activity: optimal flight temperature 17–23°C, with some individuals capable of flight at 12°C.

Larvae are oligophagous herbivores feeding on leaves of Amaranthus species (primary host), spinach (Spinacia oleracea), beet/sugar beet (Beta vulgaris), cotton (Gossypium), maize (Zea mays), and soybean (Glycine max). Adults require nectar feeding (honey solution in laboratory; natural nectar sources in field) for survival; even one day without nectar significantly depresses subsequent flight activity.

• Amaranthus spp. - primary larval host plantMain host in Africa and Asia; causes complete foliage loss under severe outbreaks
• Beta vulgaris - larval host plantIncludes sugar beet and beetroot; common name 'Beet Webworm' derives from this association
• Spinacia oleracea - larval host plantDocumented host
• Gossypium - larval host plantCotton
• Zea mays - larval host plantMaize
• Glycine max - larval host plantSoybean
• Apanteles hemara - larval endoparasitoidMost important natural enemy; solitary braconid wasp that parasitizes young larvae (1–4 days old preferred)

Complete metamorphosis with egg, larva, pupa, and adult stages. Larval development includes web-building behavior on host foliage. Pupation site not explicitly described in sources but presumably within or near larval shelters. Adult longevity and reproductive period documented in laboratory: females have 3-day pre-oviposition period, lay eggs for up to 20 days. Developmental timing temperature-dependent.

Larvae construct silk webs on host plant foliage and feed within these shelters, hence 'webworm' common name. Adults exhibit temperature-dependent flight activity with optimal range 17–23°C; 10% of females capable of continuous long-duration flight even at 12°C. Females fly more actively during pre-oviposition period. Flight activity not clearly separated from reproductive period. Mating status has no clear effect on flight activity. Adults require frequent nectar feeding to maintain flight capability.

Herbivore and agricultural pest; can cause complete defoliation of amaranth crops. Serves as host for specialist parasitoids including Apanteles hemara, supporting parasitoid population dynamics. Expansion into new regions may disrupt local food webs and compete with native herbivores.

Significant agricultural pest of amaranth, spinach, beet, and other crops in tropics and subtropics; has become established in temperate regions through human-mediated transport. Subject of research for integrated pest management including host plant resistance (certain amaranth accessions show strong antibiosis) and biological control using Apanteles hemara. Transcriptome sequencing has been performed to develop molecular tools for pest management. Monitored through citizen science platforms (iNaturalist, observation.org) for tracking range expansion.

• Other Spilomelinae crambidsSimilar size and general appearance; distinguished by specific wing pattern with recurved white markings and association with amaranth/beet hosts
• Other 'webworm' mothsLarval web-building behavior shared with many Crambidae; distinguished by host plant specificity and adult wing pattern

• agricultural pest
• amaranth pest
• global distribution
• range expanding
• biological control target
• transcriptome available
• nectar-feeding adult

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Spoladea recurvalis . [Distribution map].
• Transcriptome analysis in the beet webworm, Spoladea recurvalis (Lepidoptera: Crambidae)
• Flight activity, reproduction, and adult nutrition of the beet webworm, Spoladea recurvalis (Lepidoptera: Pyralidae)
• THE BEETROOT MOTH SPOLADEA RECURVALIS (FABRICIUS, 1775) (LEPIDOPTERA CRAMBIDAE) EXPANDS ITS SPREAD IN ITALY: NEW RECORDS WITH FIRST OCCURRENCE IN SOME REGIONS
• Beet webworm, Spoladea recurvalis Fabricius (Lepidoptera: Crambidae) new to the Adrar region (south-west of Algeria) with comments on host plants and morphometry
• Effects of Host Age and Density on the Performance of Apanteles hemara (Hymenoptera: Braconidae), a Larval Endoparasitoid of Spoladea recurvalis (Lepidoptera: Crambidae)
• Sex-specific spatial and temporal gene expressions of Pheromone biosynthesis activating neuropeptide (PBAN) and binding proteins (PBP/OBP) in Spoladea recurvalis
• Temperature-dependent development, survival and reproduction ofApanteles hemara(Nixon) (Hymenoptera: Braconidae) onSpoladea recurvalis(F.) (Lepidoptera: Crambidae)
• Expression of Resistance in Amaranthus spp. (Caryophyllales: Amaranthaceae): Effects of Selected Accessions on the Behaviour and Biology of the Amaranth Leaf-Webber, Spoladea recurvalis (Lepidoptera: Crambidae)
• The Effects of Pest-Resistant Amaranth Accessions on the Performance of the Solitary EndoparasitoidApanteles hemara(Hymenoptera: Braconidae) Against the Amaranth Leaf-WebberSpoladea recurvalis(Lepidoptera: Crambidae)
• Temperature dependent immunological responses of Spoladea recurvalis exposed to entomopathogenic fungi.