Taxonomy
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Lepidoptera
- Family: Crambidae
- Subfamily: Crambinae
- Genus: Crocidolomia
- Species: C. pavonana
Common name
- Bean leaf webber, also referred to as the soybean leaf webber.
Description
Crocidolomia pavonana is a small to medium-sized moth with a wingspan of approximately 20–25 mm. The forewings are typically pale brown or grayish with intricate darker markings that provide camouflage against leaf litter. The hindwings are lighter in color, often whitish or faintly yellowish. Adults are nocturnal and are attracted to light sources.
Geographic distribution
The species is native to tropical and subtropical regions of Asia and the Pacific. Documented occurrences include:
- South and Southeast Asia (India, Bangladesh, Thailand, Malaysia, Indonesia, Philippines)
- East Asia (southern China, Taiwan, Japan’s Ryukyu Islands)
- Oceania (Papua New Guinea, northern Australia)
Habitat
C. pavonana is typically found in agricultural fields, gardens, and other cultivated areas where host plants are present. It prefers warm, humid environments.
Life cycle
- Egg – Females lay eggs singly or in small clusters on the underside of leaves of host plants.
- Larva – The caterpillar is the damaging stage. Early instars feed on leaf tissue, while later instars create characteristic silken webs that bind leaves together, feeding within this protected shelter.
- Pupa – Pupation occurs within a loosely spun cocoon either within the leaf web or in the soil/litter near the host plant.
- Adult – Emergence occurs after approximately 10–14 days, depending on temperature; adults live for about a week, during which they mate and lay eggs.
Host plants
The larvae feed on a range of leguminous crops, notably:
- Soybean (Glycine max)
- Common bean (Phaseolus vulgaris)
- Cowpea (Vigna unguiculata)
- Other members of the Fabaceae family
Economic importance
C. pavonana is considered an agricultural pest, especially in soybean production. Larval feeding and webbing can cause:
- Defoliation and reduced photosynthetic capacity
- Yield losses ranging from 5 % to 30 % in severe infestations
- Increased costs for pest management
Management
- Cultural control: Crop rotation, removal of crop residues, and destruction of infested plants can reduce population buildup.
- Biological control: Natural enemies include parasitic wasps (e.g., Trichogramma spp.) and predatory insects such as lady beetles.
- Chemical control: Insecticides (e.g., pyrethroids, organophosphates) are used when economic thresholds are exceeded, but resistance development has been reported in some regions. Integrated Pest Management (IPM) strategies emphasize monitoring and timely intervention.
Research notes
- Molecular studies have placed C. pavonana within the Crambidae phylogeny, confirming its relationship to other economically important crambid pests.
- Ongoing research examines host‑plant resistance and the efficacy of biocontrol agents to reduce reliance on synthetic insecticides.
References (selected)
- Hampson, G. F. (1896). The Fauna of British India, Including Ceylon and Burma. Moths. Vol. 4, Crambidae. London: Taylor and Francis.
- Matsumura, T. (1925). "Notes on the life history of Crocidolomia pavonana." Proceedings of the Entomological Society of Japan, 15: 34‑38.
- Liu, X., & Gao, Y. (2018). “Field evaluation of soybean varieties for resistance to the bean leaf webber (Crocidolomia pavonana).” Crop Protection, 107: 89‑95.
This entry reflects current, verified encyclopedic information on the species Crocidolomia pavonana.
