Aphis pomi DeGeer
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Aphidoidea, entry/Aphididae.
Common name: Apple aphid.
Geographical distribution: Wherever apples are grown. CIE map #87, 1969 (revised).
Host plants: Apple, pear quince and other members of the family Rosaceae.
Morphology: The body of the apterous female is light to dark green, the antennae are yellow and the cauda and siphunculi are dark green to black. Alate females are mostly black, with a greenish abdomen; otherwise they are similar to the apterae. The length of the female body is 1.5-2.2 mm.
Life cycle: The aphids usually live on the same host throughout the year (autoecious), overwintering as eggs placed on apple branches. In the spring the emerging aphids reproduce by parthenogenesis till autumn, when males and sexual females appear and mate. The threshold of development is around 6ºC; at 16-20ºC a generation requires about 12 days, and each female has a average of 70 progeny. Summer irrigation, which promotes apple growth, also encourages increases in the aphids’ populations. Prior infestations by the pear lace bug, the tingid Stephanitis pyri (Fabricius), hinder the settlement of A. pomi.
Economic importance: The feeding of A. pomi causes downwards curling of young apple leaves, flower wilting and even plant stunting. Pale-green tubercles may arise on the young fruit. Its meager honeydew output is usually collected by ants, with little attendant sootymold. The pest also transmits a plant virus. The economic importance of this pest in the Middle East has declined in recent years due to being displaced by the spirea aphid, Aphis spiraecola Patch.
Management
Monitoring: Concentrations of pest eggs should be noted in autumn and observed for aphid emergence in early spring, especially on adventitious apple branches, which grow early and serve as feeding sites for A. pomi.
Chemical control: The pest is susceptible to organophosphates and can also be controlled by white oils and by insecticidal soaps. Best results in fruit-bearing orchards can be obtained when the trees are sprayed prior to blooming; seedlings should be treated when 10-20 are seen per terminal branch.
Biological control: Planting or leaving weed strips between apple rows encourages the populations of the generalist natural enemies of the apple aphid, such as predatory Chrysopidae, Cecidomyiidae, Coccinellidae, Hemiptera and Syrphidae, as well as spiders.
References
Basky, Z., Perring, T.M. and Tobias, I. 2001. Spread of zucchini yellow mosaic potyvirus in squash in Hungary. Journal of Applied Entomology 125: 271-275.
Hogmire, H.W., Brown, M.W., Schmitt, J.J. and Winfield, T.M. 1992. Population development and insecticide susceptibility of apple aphid and spirea aphid (Homoptera, Aphididae) on apple. Journal of Entomological Science 27: 113-119.
Lawson, D.S. and Weires, R.W. 1991. Management of European red mite (Acari, Tetranychidae) and several aphid species on apple with petroleum oils and an insecticidal soap. Journal of Economic Entomology 84: 1550-1557.
Oppenheim, D. 1994 (Ed.). A Guide to Integrated Pome Pest Management in Israel. Israel Ministry of Agriculture, Extension Service.
Rutz, C.H., Hugentobler, U., Chi, H., Baumgartner, J.H. and Oertli, J.J. 1990. Energy flow in an apple plant-aphid (Apis pomi De Geer) (Homoptera: Aphididae) ecosystem, with respect to nitrogen fertilization. Plant and Soil 124: 273-279.
Wyss, E. 1995. The effects of weed strips on aphids and aphidophagous predators in an apple orchard. Entomologia Experimentalis et Applicata 75: 43-49.
Swirski, E. and Amitai, S. 1999. Annotated list of aphids (Aphidoidea) in Israel. Israel Journal of Entomology 33: 1-120.