Aphis spiraecola

Patch, 1914

Spirea aphid, green citrus aphid, apple aphid

Aphis spiraecola is a described by Edith Marion Patch in 1914. It is a significant agricultural pest of citrus, apples, and numerous ornamental plants across temperate and tropical regions worldwide. The species exhibits remarkable flexibility, colonizing over 65 plant across more than 20 . It reproduces primarily through across most of its range, with holocyclic producing sexual morphs on primary hosts Spiraea and Citrus. The species has displaced native Aphis pomi in some regions and is considered in many areas where it has been introduced.

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

Pronunciation

How to pronounce Aphis spiraecola: /ˈeɪfɪs ˌspɪreaɪˈkoʊlə/

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Identification

Bright greenish-yellow to apple green body with dark brown and . Yellowish-green features dusky lateral patches on each segment with membranous pale dorsum. Lacks marginal on lower abdomen—this distinguishes it from the morphologically similar Aphis pomi, which possesses these tubercles. of the mitochondrial COI gene provides reliable -level identification, particularly useful for distinguishing stages and where morphological characters are less reliable.

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Habitat

Found on young growth of woody shrubs and trees, particularly those with shrubby growth habits. Colonizes young buds, shoots, flowers, and leaves of plants. Primary hosts are Spiraea spp. and Citrus spp.; secondary hosts span numerous including Caprifoliaceae, Compositae, Rosaceae, Rubiaceae, and Rutaceae. Absent from cold regions; thrives in temperate to tropical climates.

Distribution

Native to the Far East; now globally distributed across temperate and tropical regions. Present in North America (first recorded 1907), South America, Europe (Mediterranean region from 1939, spreading northward to UK, Germany, and Scandinavia from 2000s onward), Africa (from 1960s), Asia, and Oceania (Australia from 1926, New Zealand from 1931). Not established in cold climates.

Diet

Phloem sap feeder specializing on young, succulent plant tissues. Feeds on young buds, flowers, shoots, and leaves. : documented on over 65 plant including Citrus spp., Malus spp. (apple), Pyrus spp. (pear), Prunus spp. (stone fruits), Theobroma cacao, Carica papaya, and Annona spp. Shows preference for woody plants with shrubby growth habit; citrus and apples are most economically significant .

Life Cycle

Development from newborn nymph to female takes 6–10 days depending on temperature (6–7 days at 28–30°C, 9–10 days at 22–24°C; field development averages 8.1–8.6 days). Reproduces parthenogenetically across most of geographical range; holocyclic produce sexual morphs with primary Spiraea and Citrus. Can theoretically produce 20+ per vegetation season on apple. Average ranges from 9.5–10.5 nymphs per female under laboratory conditions to 20.7–21.2 nymphs under field conditions; approximately 67% reach adulthood.

Behavior

Forms dense colonies on young plant growth. Exhibits strong potential due to polyphagy and rapid ; easily establishes in new areas through movement of fruits and ornamental plants. Survives and reproduces readily in introduced ranges barring cold climate limitations.

Ecological Role

Major agricultural pest causing direct feeding damage to young growth and transmitting plant viruses. Serves as prey for numerous including lady beetles (Coccinellidae) such as Scymnus syriacus. Natural enemy often insufficient for adequate . Displaces native Aphis pomi in some regions through competitive superiority.

Human Relevance

Significant economic pest of citrus, apple, and ornamental industries worldwide. Causes direct yield loss through feeding damage and indirect losses through virus transmission. Subject to intensive management; imidacloprid favored for orchard control, with ethion, parathion-ethyl, dimethoate, fenitrothion, and dimefox also used. has been documented in some (e.g., Greece). Accurate identification essential for effective management due to differential susceptibility compared to Aphis pomi.

Similar Taxa

Aphis pomiOverlapping plants and 'apple ' create frequent confusion. Distinguished morphologically by presence of marginal on lower in A. pomi (absent in A. spiraecola), and by shorter rostral segment in A. pomi. Molecular identification via COI barcoding or real-time recommended where morphological uncertainty exists.
Aphis gossypiiBoth are pests of agricultural crops; may co-occur on some . Distinguished by host preferences and morphological details.
Toxoptera citricidaBoth are citrus-feeding aphids; A. citricola was synonymized with A. spiraecola, while T. citricida remains distinct. Historical taxonomic confusion resolved by Hille Ris Lambers in 1975.