Aphis spiraecola Patch
(Also known as Aphis citricola van der Goot)
Common name: Spirea aphid.
Geographical distribution: Almost cosmopolitan; in the Middle East since the late 1960’s. CIE Map #256, 1969.
Host plants: Polyphagous.
Morphology: The body of apterous females is yellow-green, sometimes with a pink hue; the head, siphunculi and cauda are brown-black and the length of the body is 1.4-2.1 mm. The head and thorax of alate females are brown-black, the abdomen is green and the siphunculi and cauda are dark; body length is 1.4-2.0 mm.
Life history: In the Middle east tis pest reproduces only by viviparous parthenogenesis, each female giving birth to about 60 progeny when feeding on citrus foliage. At 25ºC the pest completes a generation within 7-10 days. The threshold of development is around 2.5ºC, which means that the pest develops during winter and could explain its rapid, almost sudden infestation of citrus groves in early spring. The pest’s departure is also rapid and sudden, possibly due to khamsin events in early summer. During such events the aphids move from the newly-growing, external parts of the trees to its central area, often dropping to the ground and dying there. Such behavior is exacerbated on parched trees, uncommon on well-irrigated trees.
Economic importance: The feeding of the spirea aphid on young citrus foliage in the spring causes severe, characteristic curling and deformation of young leaves and twigs. Blossoms and young fruit (especially of soft-skinned varieties) drop prematurely, and the trees may be stunted. The consequences of a secondary, autumnal peak in pest outbreak are usually less severe. In addition, infested trees are contaminated by the the pest’s abundant honeydew and subsequently-developing sootymold. The aphid is a vector of the citrus tristeza virus and other plant viruses. Young avocado trees also suffer from the pest, as do peach and apple trees, and many ornamentals. On apples Aphis spiraecola has displaced Aphis pomi De Geer as the dominant aphid on its leaves. During recent years the injury caused by spirea aphid to citrus seems to have declined in the Middle East
Chemical control: Due to the fact that young trees are especially vulnerable to this pest, pest damage can be reduced by spraying only them; such control activities should not be undertaken during khamsins. Carbamates, some organophosphates and acetamiprid control the spirea aphid.
Biological control: The spirea aphid is attacked by predatory Cecidomyiidae, Chrysopidae, Coccinellidae and Syrphidae. However, due to the pest’s short life cycle and sudden arrival and departure from citrus, these predators have little effect on the aphid’s populations. Some endoparasitoid Aphidiidae attack A. spirea, but seldom complete their development therein; the causative mechanism is unknown. Several entomopathogenic fungi also infect the aphid, but none of these natural enemies appear to reduce the pest’s damage.
Drishpoun, Y. (Ed.) 2000. A Guide to the Control of Citrus Pests. Israel Ministry of Agriculture Extension Service, Bet Dagan.
Mescheloff, E. and Rosen, D. 1993. Biosystematic studies on the Aphidiidae of Israel (Hymenoptera: Ichneumonoidea). 4. The genera Trioxys and Binodoxys. Israel Journal of Entomology 27: 31-47.
Swirski, E. and Amitai, S. 1999. Annotated list of aphids (Aphidoidea) in Israel. Israel Journal of Entomology 33: 1-120.
Wang, J.J. and Tsai, J.H. 2000. Effect of temperature on the biology of Aphis spiraecola (Homoptera: Aphididae). Annals of the Entomological Society of America 93: 874-883.
Zehavi, A. and Rosen, D. 1987. Population trends of the spirea aphid, Aphis citricola van der Goot, in a citrus grove in Israel. Journal of Applied Entomology 104: 271-277.