Chloridea virescens

(Fabricius, 1777)

Tobacco Budworm Moth, Tobacco Budworm

Chloridea virescens, the tobacco budworm , is a noctuid moth native to the Americas and a major agricultural pest. The was transferred from Heliothis to Chloridea in 2013 based on genetic and morphological evidence. are brownish with green tinge and distinctive wing banding. Larvae feed on buds, blossoms, and fruit of diverse plants, causing significant crop damage. The species has developed rapid resistance to multiple classes, making management challenging.

Chloridea virescens by (c) Nick Block, some rights reserved (CC BY), uploaded by Nick Block. Used under a CC-BY license.

Tobacco budworm 2 by wikipedia. Used under a Public domain license.

Chloridea virescens chickory by Beatriz Moisset. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Chloridea virescens: //klɔːˈrɪdiə vɪˈrɛskɛnz//

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

Identification

distinguished from similar noctuids by three dark forewing bands with cream borders and whitish hindwings with dark band. nearly identical to Helicoverpa zea (corn earworm); primary ribs terminate before reaching in C. virescens versus extending to rosette in H. zea. Early instar larvae difficult to separate from H. zea; microspine patterns differ. Reliable separation of eggs and young larvae requires -specific immunoassay or Bacillus thuringiensis feeding disruption .

Images

Appearance

are brownish with a light green tinge, measuring 28–35 mm wingspan. Forewings display three dark bands, each bordered by whitish or cream coloration. Hindwings are whitish with a dark band at the margin. Females are generally darker than males. Larvae are yellow to yellowish-green upon hatching, becoming variable in later instars—greenish, pinkish, dark red, or maroon—with a broad brown capsule. Whitish and bands run the body length, with a broad brown lateral band. Larvae bear black thornlike microspines. are spherical with flattened base, 0.5–0.6 mm , with 18–25 radiating ridges; initially whitish or yellowish, turning grey with age.

Habitat

Agricultural fields, particularly tobacco and cotton; also vegetable crops, flower crops, and weedy areas. Overwinters in soil as pupae in southern states; can survive northern climates in sheltered environments such as greenhouses.

Distribution

Eastern and southwestern United States; disperses northward to New England and southern Canada during late summer. Established in California, Caribbean, Central America (Mexico, Guatemala, Panama), and South America (Brazil). Specific documented in Louisiana, Florida, Virginia, North Carolina, South Carolina, Georgia, Texas, Colorado, and the Antilles.

Seasonality

Active during warmer months, late spring to early fall. emerge March–May in southern United States. Undergoes 4–5 annually depending on region and temperature. Overwinters as pupae.

Diet

Larvae feed on buds, blossoms, terminal growth, leaf petioles, stalks, and fruit of plants. Documented hosts include tobacco (Nicotiana), cotton, alfalfa, clovers, soybean, flax, cabbage, cantaloupe, lettuce, pea, tomato, geranium, and numerous weeds including cranesbill, toadflax, deergrass, beggarweed, wild tobacco, vervain, ruellia, and mallow. Host preference varies regionally; maternal inheritance of host preference has been demonstrated.

Host Associations

Nicotiana - primary source of
Gossypium - major principal in Texas
Gossypium hirsutum - cotton
Medicago sativa - alfalfa
Trifolium - clovers
Glycine max - soybean
Linum usitatissimum - flax
Brassica oleracea - cabbage
Cucumis melo - cantaloupe
Lactuca sativa - lettuce
Pisum sativum - pea
Solanum lycopersicum - tomato
Pelargonium - geranium
Geranium dissectum -
Geranium carolinianum - cranesbill, key early season in Mississippi
Linaria canadensis - toadflax, early season in Georgia
Panicum - deergrass, for third in Georgia
Desmodium - beggarweed, for later in Georgia
Nicotiana repanda - wild tobacco, Texas
Verbena - vervain, Texas
Ruellia - Texas
Malva - mallow, Texas

Life Cycle

Complete with four stages: , larva, pupa, . Eggs laid on blossoms, fruit, or terminal growth; hatch in 2.6–10.1 days at 20°C, faster at higher temperatures. Larvae undergo 5–6 instars (rarely 7), lasting 1.9–10.1 days depending on temperature and instar. observed from third or fourth instar. occurs in soil; pupal stage lasts 11–22 days, temperature-dependent. Adults live 15–25 days depending on temperature. Overwinters as pupae; induced by short days or low temperatures.

Behavior

Larvae tunnel into plant buds, blossoms, and fruit, causing characteristic ragged, distorted leaf growth from damaged buds. Cannibalistic from third or fourth instar. Larvae defend against by expelling oral exudate that agitates attackers, enabling escape. Males produce hair-pencil during mating that attract females; females rely on to detect these signals. Maternal inheritance of oviposition preference demonstrated.

Ecological Role

Agricultural pest causing significant crop damage. Serves as for multiple including Trichogramma pretiosum ( parasitoid), Microplitis croceipes (larval parasitoid), Cardiochiles nigriceps (larval parasitoid on tobacco), and Meteorus autographae. High natural rates documented across all life stages.

Human Relevance

Major pest of field crops, particularly tobacco and cotton, with historical records of damage dating to early 1800s. Rapid evolution of resistance documented: resistance within 14 years, carbaryl within 10 years, within 7 years, methomyl within 5 years. Successfully controlled in U.S. and Mexico by Bt cotton producing Cry1Ac and Cry1Ab toxins. Resistance to Bt toxins evolving; 7-fold resistance increase observed after 12 laboratory selection episodes. Subject of sterile insect release and irradiation studies. Monitoring conducted via -baited cone traps.

Similar Taxa

Helicoverpa zeaCorn earworm; and early instar larvae nearly identical, requiring molecular or methods for reliable separation. distinguished by wing pattern details. Both occur on similar and may be found together.
Helicoverpa armigeraOld World bollworm; similar and pest status, but geographic ranges largely non-overlapping.

More Details

Taxonomic history

Transferred from Heliothis to reinstated Chloridea in 2013 based on genetic and morphological research. Formerly treated as Heliothis virescens.

Temperature effects on development

Development rate negatively correlated with temperature. Larval instar development: 2.6–10.1 days at 20°C versus 1.9–5.7 days at 25°C. Pupal stage: 22 days at 20°C, 13 days at 25°C, 11.2 days at 30°C. longevity: 25 days at 20°C, 15 days at 30°C.

Insecticide resistance timeline

Resistance acquired to (14 years after introduction), carbaryl (10 years), (7 years), methomyl (<5 years). Resistance to Bt toxins documented with frequency estimated at 0.001 in wild .

Parasitoid defenses

Larvars expel oral exudate against approaching Cardiochiles nigriceps females, causing to groom and allowing larval escape. Winthemia rufopicta on larvae are destroyed by biting, crushing, puncturing, or ingestion.

Juvenile hormone physiology

Mating induces 5–15 fold increase in production by in females, stimulating and production. Males synthesize juvenile hormone in accessory glands and transfer to females during copulation.

Regional host shifts

Documented seasonal plant in Georgia: 1–2 on toadflax (April–May), generation 3 on deergrass (June–July), generations 4+ on beggarweed (July–October).