Helicoverpa armigera

Source: Wikipedia, the free encyclopedia.

Cotton bollworm
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Superfamily: Noctuoidea
Family: Noctuidae
Genus: Helicoverpa
Species:
H. armigera
Binomial name
Helicoverpa armigera
(Hübner, [1808])
Synonyms
  • Chloridea armigera Hübner,
  • Chloridea obsoleta Duncan & Westwood, 1841
  • Helicoverpa commoni Hardwick, 1965
  • Helicoverpa obsoleta Auctorum,
  • Heliothis armigera Hübner, 1805
  • Heliothis conferta Walker, 1857
  • Heliothis fusca Cockerell, 1889
  • Heliothis pulverosa Walker, 1857
  • Heliothis rama Bhattacherjee & Gupta, 1972
  • Heliothis uniformis Wallengren, 1860
  • Noctua armigera Hübner, [1805]
  • Noctua barbara Fabricius, 1794[1]

Helicoverpa armigera is a species of

polyphagous and cosmopolitan pest species. It should not be confused with the similarly named larva of the related species Helicoverpa zea
.

Distribution

This species comprises two sub-species: Helicoverpa armigera armigera is native and widespread in central and southern Europe, temperate Asia and Africa; Helicoverpa armigera conferta is native to Australia, and Oceania.[3] The former sub-species has also recently been confirmed to have successfully invaded Brazil[4] and has since spread across much of South America and reached the Caribbean. It is a migrant species, able to reach Scandinavia and other northern territories.[5]

Morphology

Eggs
Larva
Maize field habitat, Poland

The cotton bollworm is very variable in both size and colour. The body length varies between 12 and 20 millimetres (1⁄2 and 3⁄4 in) with a wingspan of 30–40 millimetres (1+1⁄4–1+1⁄2 in). The fore wings are yellowish to orange in females and greenish-gray in males, with a slightly darker transversal band in the distal third.[6] The external transversal and submarginal lines and the reniform spot are diffused. The hind wings are a pale yellow with a narrow brown band at the external edge and a dark round spot in the middle.[5]

Lifecycle

Lateral view
Mounted, dorsal view
Mounted, ventral view

The female cotton bollworm can lay several hundred eggs, distributed on various parts of the plant. Under favourable conditions, the eggs can hatch into larvae within three days and the whole lifecycle can be completed in just over a month.[6]

The

eggs are spherical and 0.4 to 0.6 millimetres (1⁄64 to 3⁄128 in) in diameter, and have a ribbed surface. They are white, later becoming greenish.[5]

The larvae take 13 to 22 days to develop, reaching up to 40 millimetres (1+1⁄2 in) long in the sixth

cannibalise
each other. If disturbed, they fall from the plant and curl up on the ground.

The

cocoon[6] over 10 to 15 days in soil at a depth of 4–10 centimetres (1+1⁄2–4 in), or in cotton bolls or maize ears.[5]

Host plants

The cotton bollworm is a highly polyphagous species.

Amaranthus genera.[5]

Economic significance

The greatest damage is caused to

Bacillus thuringiensis toxin) improved yields of lint.[10]

Genetics

The genomes of Helicoverpa armigera conferta and Helicoverpa zea were published in July 2017.[

CYP337B3) is unassessed as of 2019 and such information will be needed to monitor changes in resistance across populations over time.[3]

Population genetics

Overall H. amerigera is the best characterised out of Helicoverpa due to its longstanding and severe agricultural impact.[3]

Management

Prevention

The

Plantwise and their partners suggest planting trap crops and intercropping with crops including cowpea, sunflower, maize, marigold. They also recommend rotating with cereal crops and other non-host crops to prevent the population from building up.[11][12][13][14]

Partners of Plantwise suggest introducing spacing when planting, removing weeds, crop residues and volunteer crops.[15]

Introducing bird perches and providing habitats for natural enemies are methods that can be used to prevent pest populations building up.[12][13][14][15]

Monitoring

The caterpillars feed on buds, flowers, grains, fruits, pods; sometimes leaves and stems. In cotton they are found on the vegetative part and reproductive structures. In corn, millet at sorghum they attack the grain. In tomato and beans caterpillars bore into young fruits and in chickpea they attack foliage and consume developing seeds.[14]

Direct control

In small plots, Plantwise suggests handpicking and destroying eggs and young caterpillars is possible.[14]

CABI and Plantwise partners recommend introducing light and pheromone traps to trap adult moths.[11][12][14][15]

Plantwise and partners have suggested the release of natural enemies, including the parasitoid Trichogramma brassilences or T. pretiosum as methods of control.[14][15]

Sources

References

  1. ^ a b c "Pest Risk Analysis" (PDF). Archived from the original (PDF) on 2010-11-17. Retrieved 2010-11-27.
  2. British Wildlife Publishing
    . p. 374.
  3. ^
    S2CID 52944198
    .
  4. PMID 24260345
    .
  5. ^ a b c d e f g h "AgroAtlas - Pests - Helicoverpa armigera Hbn. - Cotton Bollworm". www.agroatlas.ru.
  6. ^ a b c d "Crop Compendium - Bayer - Crop Science". www.cropscience.bayer.com.
  7. doi:10.5519/havt50xw
    .
  8. ^ "Isca Tecnologias - Produtos - Acttra Noctuideo". www.isca.com.br. Retrieved 2021-07-09.
  9. ^ "ISCA Technologies Integrated Pest Management (IPM) Tools & Solutions". ISCA Technologies. Retrieved 2021-07-09.
  10. ^ "Bt Cotton". www.bt.ucsd.edu.
  11. ^
    S2CID 213082645
    . Retrieved 2020-06-03.
  12. ^
    S2CID 253990995
    . Retrieved 2020-06-03.
  13. ^
    S2CID 253998514
    . Retrieved 2020-06-03.
  14. ^
    doi:10.1079/pwkb.20167800979
    . Retrieved 2020-06-03.
  15. ^
    S2CID 253999055
    . Retrieved 2020-06-03.

External links

Wikimedia Commons has media related to Helicoverpa armigera.
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