Aphis gossypii

Glover, 1877

cotton aphid, melon aphid, melon and cotton aphid, greenfly

is a small sap-sucking and significant agricultural pest with a global distribution. It infests in at least three , particularly Cucurbitaceae, Rutaceae, and Malvaceae, causing direct damage through feeding and indirect damage as a of plant viruses. The exhibits complex strategies including both holocyclic (sexual) and anholocyclic () depending on geographic location and climate. It has developed to multiple , complicating management efforts.

Aphis gossypii by (c) Justin Paulin, some rights reserved (CC BY), uploaded by Justin Paulin. Used under a CC-BY license.

Aphis gossypii by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Pronunciation

How to pronounce Aphis gossypii: /ˈeɪfɪs ˌɡɒsiˈpiːaɪ/

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

Identification

Distinguished from other by the combination of black that are wide at the base and one-fifth of body length, legs with black , and yellow approximately three-quarters of body length. Wingless females show green coloration with these features; winged forms display black and with yellowish-green bearing black spots. can be confused with other aphids but show characteristic dark head, thorax, and with -dusted dull appearance. Molecular identification may be necessary where morphological overlap occurs with closely related Aphis species.

Images

Appearance

Wingless females have an ovoid body approximately 2 mm long in varying of green. Legs and are ; antennae are three-quarters of body length. of , , and are black. Cylindrical black are wide at the base and one-fifth of body length. Winged females have a body with black and , yellowish-green with black spots, and longer antennae than wingless forms. vary in color from green to tan to gray, often with dark head, thorax, and ; abdomen usually dark green. Body appears dull due to secretions. are oval, yellow when laid, turning black.

Habitat

Agricultural and horticultural environments; thrives in warm conditions outdoors in southern Europe but survives only under glass in northern Europe. Found on cultivated and some wild plants. In temperate regions, requires protected environments for year-round survival.

Distribution

in tropical and temperate regions worldwide except extreme northern areas. Documented in North and South America, Central Asia, Africa, Australia, Brazil, East Indies, Mexico, Hawaii, and most of Europe. In the former Soviet Union found up to 54°N. Specific records include: Europe (Austria, Azores, Belgium, Britain, Bulgaria, Czechoslovakia, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Malta, Netherlands, Norway, Poland, Portugal, Romania, Sardinia, Sicily, Spain, Sweden, Switzerland, Yugoslavia), Asia (Afghanistan, Bonin Islands, Burma, Ceylon, China, Cyprus, Gaza Strip, Hong Kong, India, Indonesia, Iran, Iraq, Israel, Japan, Jordan, Korea, Lebanon, Malaysia, Nepal, Pakistan, Philippines, Saudi Arabia, Singapore, South Arabian Protectorates, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen, USSR), Africa (Algeria, Angola, Burundi, Cameroon, Central African Republic, Chad, Congo, Dahomey, Egypt, Ethiopia, Ghana, Guinea, Ivory Coast, Kenya, Libya, Madagascar, Madeira, Malawi, Mali, Mauritania, Mauritius, Morocco, Mozambique, Niger, Nigeria, Réunion, Rwanda, Rhodesia, St. Helena, Senegal, Seychelles, Sierra Leone, Somalia, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Upper Volta, Zambia), Australasia and Pacific Islands (Australia, Caroline Islands, Fiji, Gilbert Islands, Hawaii, Johnston Island, Kermadec Island, Mariana Islands, Marshall Islands, New Caledonia, New Hebrides, New Zealand, Norfolk Island, Papua & New Guinea, Phoenix Islands, Pitcairn Island, Samoa, Society Islands, Tokelau Islands, Tonga, Wallis Island, Irian Jaya), North America (Canada, Mexico, USA), Central America and West Indies ( Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, West Indies), South America (Argentina, Bolivia, Brazil, Chile, Colombia, Guyana, Paraguay, Peru, Surinam, Uruguay, Venezuela). Origin unknown.

Seasonality

In southern US (as far north as Arkansas), is not important and females reproduce parthenogenically year-round when weather permits. Further north, involves between primary and secondary with sexual reproduction in autumn. In Europe, reproduces exclusively asexually with up to nearly 50 per year under favorable conditions. In Russia, overwinters as on wild plants.

Diet

Phloem sap feeder. Documented include at least 60 in Florida and approximately 700 worldwide. Major hosts: cotton (Gossypium), melons and other (Cucumis melo, Citrullus lanatus, Cucurbita spp., Cucumis sativus), citrus (Citrus), pepper (Capsicum), eggplant (Solanum melongena), okra (Abelmoschus esculentus), asparagus (Asparagus), hibiscus (Hibiscus), (Fragaria), and cumin (Cuminum cyminum). Also feeds on various wild plants including Catalpa, Rhamnus, and plants in Rosaceae, Chenopodiaceae, Malvaceae, Cruciferae, Cucurbitaceae, Solanaceae, and Compositae.

Host Associations

Cuminum cyminum - Laboratory study on variety GC-4 in Rajasthan, India
Gossypium spp. - primary economic ; cotton
Cucumis melo - melon
Citrullus lanatus - watermelon
Cucumis sativus - cucumber
Cucurbita spp. - squash, pumpkin
Citrus spp. - citrus
Capsicum spp. - pepper
Solanum melongena - eggplant/aubergine
Abelmoschus esculentus - okra
Asparagus officinalis - asparagus
Hibiscus spp. - primary in some holocyclic
Fragaria spp. -
Catalpa spp. - primary in holocyclic
Rhamnus spp. - primary in holocyclic
Rosa spp. - secondary Rosaceae
Chenopodium spp. - secondary Chenopodiaceae

Life Cycle

Four nymphal precede the stage. Under laboratory conditions on cumin at ambient temperatures: first instar 1.30±0.42 days, second instar 2.05±0.62 days, third instar 2.40±0.52 days, fourth instar 1.45±0.45 days; total nymphal duration 7.75±1.61 days. Development rate temperature-dependent: maturation in about 20 days at 10°C and about 4 days at 30°C. Adult longevity 9.65±1.75 days; total lifespan 17.75±2.91 days. strategy varies geographically: anholocyclic (parthenogenetic year-round) in warm climates and southern Europe; holocyclic (with sexual phase and ) in temperate regions with primary trees (Catalpa, Rhamnus, Hibiscus) and secondary herbaceous hosts.

Behavior

Forms colonies on undersides of leaves, growing tips, and stems. Spatial distribution on cotton shows -dependent : aggregation decreases as density increases to approximately 2 individuals per leaf, then increases again at densities above 3 individuals per leaf. Winged forms develop for between . Produces . Alarmed by presence, causing to drop from plants. patterns: winged forms move from primary hosts to secondary hosts in spring/summer, return to primary hosts in autumn for where holocyclic.

Ecological Role

and significant agricultural pest. Acts as for crinkle, mosaic, rosette, CTV (citrus tristeza virus), and other viruses. production supports growth, reducing plant . Serves as for multiple including Aphidius colemani, Aphelinus asychis, Aphelinus gossypii, and Binodoxys indicus, and for including , , , and . influenced by natural mortality factors affecting spatial patterns.

Human Relevance

Major economic pest of cotton, , citrus, and other causing direct feeding damage (leaf curling, , premature leaf death, fruit drop) and indirect damage through virus transmission and / . Honeydew contamination of cotton lint reduces fiber quality, causing sticky, stained lint that is difficult to harvest, gin, and spin. Subject to intensive management; has developed to and via variant genes (MACEA and MACEB), and to sulfoxaflor via thickening. Target of using in and greenhouse banker systems. Sublethal insecticide exposure can stimulate and alter symbiotic bacteria.

Similar Taxa

Aphis craccivoraSimilar size and range on legumes and other ; distinguished by different proportions and host preferences
Myzus persicae, similar coloration and pest status; distinguished by presence of prominent antennal and different shape
Aphis fabaeBlack bean , similar strategies; distinguished by darker coloration and different associations
Aphis nerii, bright -orange coloration; distinguished by distinct color and oleander/

More Details

Insecticide Resistance

to and has been traced to two variant genes, MACEA and MACEB. Resistance to sulfoxaflor involves thickening.

Reproductive Biology

Parthenogenetic female lifespan approximately 20 days with production of up to 85 . on cumin: 24.45±6.21 nymphs per female with intrinsic rate of 4.80±2.01 nymphs per female per day. Pre-reproductive period 1.35±0.56 days, reproductive period 7.20±1.47 days, post-reproductive period 1.75±0.71 days.

Biological Control

Aphidius colemani, Aphelinus asychis, and other are used in programs. Banker systems using alternative (e.g., Rhopalosiphum padi on cereals) can maintain parasitoid for greenhouse management.