Aphis fabae

Scopoli, 1763

black bean aphid, blackfly, bean aphid, beet leaf aphid

Aphis fabae is a small, soft-bodied in the Aphididae, commonly known as the black bean aphid or blackfly. It is a significant agricultural pest with a broad range, attacking beans, sugar beet, and numerous other crops. The exhibits a with host alternation between a woody primary host (Euonymus europaeus, spindle tree) and herbaceous secondary hosts. It reproduces parthenogenetically during the growing season and sexually in autumn, producing . The aphid is capable of rapid increase through , and winged forms develop seasonally to facilitate between host plants.

Aphis fabae by (c) Alexis Tinker-Tsavalas, some rights reserved (CC BY), uploaded by Alexis Tinker-Tsavalas. Used under a CC-BY license.

Aphis fabae on Cirsium vulgare by Rasbak. Used under a CC BY-SA 3.0 license.

Aphis fabae, zwarte bonenluis (4) by Rasbak. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Aphis fabae: //ˈæfɪs ˈfeɪ.baɪ//

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Identification

Aphis fabae is a small black , typically 1.5-3.0 mm in length, with a broad, soft body. Wingless (apterae) are shiny black with black and legs; winged forms (alatae) have a dark and with membranous wings. The is morphologically similar to other members of the Aphis fabae complex (including A. solanella, A. cirsiiacanthoidis, and A. evonymi), and reliable identification often requires biological testing using specific plants rather than morphological characters alone.

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Habitat

Found in agricultural fields, gardens, and natural areas where plants occur. are densest on the undersides of leaves and growing tips of host plants. The shows edge-biased distribution patterns in fields, with higher densities along field margins.

Distribution

Widespread across Europe, Asia, Africa, North America, Central America, South America, and Australasia. Distribution records include: Europe (Austria, Belgium, Britain, Bulgaria, Channel Islands, Czechoslovakia, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Netherlands, Norway, Poland, Portugal, Romania, Sardinia, Spain, Sweden, Switzerland, Yugoslavia); Asia (Afghanistan, Ceylon, China, Cyprus, Formosa, India, Iraq, Israel, Japan, Jordan, Lebanon, Nepal, Pakistan, Persia, Philippines, Turkey, USSR); Africa (Cameroon, Canary Islands, Belgian Congo, Egypt, Eritrea, Kenya, Libya, Madeira, Morocco, Nigeria, Republic of South Africa, Southern Rhodesia, Sudan, Tanganyika); Australasia and Pacific Islands (Hawaii); North America (Canada, USA); Central America and West Indies; South America (Argentina, Brazil). Range expansion has been documented in Russia, with increasing in northwest Russia and northward expansion to Arkhangelsk region.

Seasonality

Activity begins in spring when fundatrices hatch from on Euonymus europaeus. to secondary occurs in spring; return migration to primary host occurs in autumn (early October in some regions) when decreasing (approximately 12 hours) and temperature around 17°C induce production of winged gynoparae and males. and egg-laying on primary host occurs in autumn.

Diet

Phloem sap from plants.

Host Associations

Euonymus europaeus - primary (winter host, spindle tree)Site of and production
Vicia faba - secondary (summer host)Broad bean; major agricultural crop
Beta vulgaris - secondary (summer host)Sugar beet; major agricultural crop
Phaseolus vulgaris - secondary (summer host)Bean; used in laboratory studies
Rumex spp. - secondary Dock
Chenopodium spp. - secondary
Carduus lanceolatus - secondary Thistle
Cirsium arvense - secondary Canada thistle; used in biological identification tests
Solanum nigrum - secondary Black nightshade; used in biological identification tests
Viburnum opulus - occasional primary Guelder rose; occasional alternation documented

Life Cycle

Heteroecious (-alternating) with holocyclic (complete) . on primary host (Euonymus europaeus) hatch in spring to produce fundatrices (stem mothers). Successive parthenogenetic, occur on secondary hosts throughout spring and summer. In autumn, decreasing and temperature induce production of winged gynoparae (which return to primary host) and males. Sexual females (oviparae) are produced on primary host; mating occurs and overwintering eggs are laid. Winged virginoparae may also disperse between secondary hosts during the growing season.

Behavior

Exhibits strong mediated by . Feeding preferences vary among morphs: gynoparae show strongest preference for primary Euonymus over secondary hosts, while virginoparae show weaker host discrimination. All morphs prefer growing leaves over mature leaves, though the strength of this preference varies. behavior influences subsequent host-finding and settling behavior. Shows edge-biased spatial distribution in agricultural fields, with higher densities along field margins.

Ecological Role

Significant agricultural pest causing direct damage through phloem feeding and indirect damage as a of plant viruses. Serves as prey for numerous and . Acts as a model organism for studies of , alternation, and insect-plant interactions.

Human Relevance

Major economic pest of beans (Vicia faba, Phaseolus vulgaris) and sugar beet (Beta vulgaris), causing yield losses through direct feeding damage and virus transmission. Subject of extensive research in , , and . Used as a model organism in studies of efficacy, thermal , and .

Similar Taxa

Aphis solanellaMember of Aphis fabae complex; morphologically indistinguishable, requires biological testing for separation. range differs: A. solanella associated with Solanum hosts.
Aphis cirsiiacanthoidisMember of Aphis fabae complex; morphologically indistinguishable. Associated with thistle (Cirsium, Carduus); cannot colonize Vicia faba or Beta vulgaris.
Aphis evonymiMember of Aphis fabae complex; non--alternating, remains on Euonymus year-round. Distinguished by brownish coloration in life (other members are black).
Aphis neriiDifferent association (oleander and milkweeds); bright orange with black legs and cornicles rather than uniformly black.
Aphis gossypiiSmaller, more variable in color (green to black), different range including cotton and cucurbits.

More Details

Taxonomic Complexity

Aphis fabae represents a with multiple morphologically similar forms. The taxonomic status of members (A. fabae s. str., A. solanella, A. cirsiiacanthoidis, A. evonymi) remains debated; some authorities treat them as or semispecies. Hybridization can occur between forms, particularly between A. evonymi and A. cirsiiacanthoidis, with postzygotic isolation mechanisms maintaining partial reproductive separation.

Population Dynamics

Optimal temperature range for growth is 16-24°C. Developmental time decreases from 16.65 days at 12°C to 5.70 days at 24°C (slight increase to 6.62 days at 28°C). peaks at 0.41 at 24°C. Temperatures above 28°C reduce and survival. of approximately 12 hours at 17°C induces production of winged forms for autumn .

Control and Management

Subject to chemical control with including lambda-cyhalothrin, though sublethal effects on parameters have been documented. (Verbena officinalis, Laurus nobilis) show aphicidal activity and are being explored as alternatives. exists among crop cultivars; some broad bean cultivars show effects reducing performance. using natural enemies and conservation of and is important in programs.