Aonidiella orientalis

Aonidiella orientalis (Newstead)

Common name: Oriental yellow scale.

Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Coccomorpha, Coccoidea, Diaspididae.

Geographical distribution: In most tropical and subtropical countries, in other regions in glasshouses.

Host plants: Polyphagous, not on conifers.

Morphology: The dorsal macroducts are one-barred, slender, 3-4 on each side of the pygidium, none on the pre-pygidial segments. The body of the female is initially yellow, pear-shaped, later brown-red, round, almost square, at maturity the prepygidial segments become somewhat sclerotized. The pygidium bears three large lobes, all externally notched, the fourth lobe is only a point. Two-three small paraphyses arise from the lobes on either side of the pygidium. The anus is located about a third of the distance between the median lobes and the vagina, around which are placed 10-12 perivulvar pores. The shield is about 2.0 mm in diameter, thin and almost transparent, yellow-brownish, round and slightly convex, the darker juvenile exuviae at center. The ventral exuvium (“velum”) is retained as a thin membrane. The winged males are yellow, about 1 mm in length, with oval, grey shields and the exuvium of the 1st instar is placed near one end.

Life history: A female lays about 120 eggs, and depending on the climate, and 3-5 annual generations are raised.

Economic importance: A serious pest of many crops, including banana, citrus, papaya and others. In the Middle East of special importance to mango, whose infested fruits show much discoloration which reduces their commercial value. At times flowers and fruits fail to develop, there is some premature fruit drop and the young trees of other, heavily infested trees may even be killed.

Management

Horticultural control: Removal of infested twigs, branches, and shoots.

Chemical control: Pesticides are usually not needed due to the controlling effect of natural enemies. But when necessary, white oils or organophosphates have been used.

Biological control: The oriental yellow scale has many natural enemies which usually reduce its populations to below their economic injury levels. Parasitoids include several species of Aphytis (Aphelinidae) and Encyrtidae, such as Habrolepis aspidioti Compere and Annecke, and the common Comperiella bifasciata Howard. Predators include Chilocorus bipustulatus L. (Coccinellidae) and Chrysoperla carnea (Stephens) (Chrysopidae).

References

Elder, R.J., Smith, D. and Bell, K.L. 1998. Successful parasitoid control of Aonidiella orientalis (Newstead) (Hemiptera: Diaspididae) on Carica papaya L. Australian Journal of Entomology 37: 74-79.

Mohammad, Z.K, Ghabbour, M.W and Tawfik, M.H. 1999. Population dynamics of Aonidiella orientalis (Newstead) (Coccoidea: Diaspididae) and its parasitoid Habrolepis aspidioti Compere & Annecke (Hymenoptera: Encyrtidae). Entomologica 33: 413-418.

Ofek, G. (and 6 co-authors) 1997. The control of the oriental red scale, Aonidiella orientalis Newstead and the California red scale, A. aurantii (Maskell) (Homoptera: Diaspididae) in mango orchards in Hevel Habsor (Israel). Alon Hano’tea 51: 212-218.

Rajagopal, D. and Krishnamoorthy, A. 1996. Bionomics and management of oriental yellow scale, Aonidiella orientalis (Newstead) (Homoptera: Diaspididae): an overview. Agricultural Reviews 17: 139-146.

Swirski, E., Wysoki, M. and Izhar, Y. 2002. Subtropical Fruit Pests in Israel. Fruit Board of Israel. 283+III (in Hebrew with an English Preface).

Website

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