Russellaspis pustulans (Cockerell)
(Formerly known as Asterolecanium pustulans Cockerell)
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Coccoomorpha, Coccoidea, Asterolecaniidae.
Common name: Pustule scale, oleander pit scale.
Geographical distribution: South-eastern Mediterranean, eastern Africa and (introduced) in Mexico, West Indies, Hawaii. CIE Map #460, 1984.
Host plants: In the Middle East the pest has been collected from around 20 host plants, including apple, carob, fig, oleander and others.
Morphology: The shield of the female is translucent, greenish, and its margins bear whitish filaments. The body is oval, about 1.0 mm in length. The dorsal part of the body margin bears 8-shaped pores that extend to the level of the vulva. There are a few ventral pores that extend from the spiracles to the margins. The antennae are vestigial.
Life cycle: This scale reproduces only by parthenogenesis, each female producing 50-60 eggs. The pest completes 2-3 annual generations, dependent on the region (the insect is sensitive to high temperatures and dry khamsin winds) and the host plant. Similar numbers of crawlers settle on apple trunks and on the branches; leaf petioles may also be infested.
Economic importance: Russellaspis pustulans is usually a secondary pest of figs and ornamentals like oleander, but has recently become a serious pest of apples in Egypt. Toxins injected by the insect into the plant induce the growth of pustule-like galls around the pest, which consequently lies in a crater surrounded by the host tissues. In heavy infestations an entire “forest” of such pustules arises on the infested twigs and retards its growth.
Management
Chemical control: The insect growth regulator, buprofezin, controls the pest on apples.
References
Abd El-Salam, A. and Mangoud, H. 2001. Development and implementation of integrated pest management to programs of apple trees in reclaimed lands in Egypt: I - The fig scale insect (FSI), Russellaspis (Asterolecanium) pustulans (Cockerell). Journal of Agriculture in the Tropics and Subtropics 102: 33-44.
Garcia, M.F. 1999. Asterolecanium pustulans Ckll. (Homoptera, Coccoidea, Asterolecaniidae): Biological study. Revista de la Facultad de Ciencias Agrarias Universidad Nacional de Cuyo 31: 7-12. [In Spanish]
Habib, A. 1943. The biology and bionomics pf Asterolecanium pustulans Ckll. (Hemiptera-Coccidae). Bulletin de la Société Fouad Ier d’Entomologie 27: 87-111.
Ismail, A.I. and Abdalla, E.F. 2001. Efficiency and residual activity of some selective compounds against Asterolecanium pustulans Cock. and Ceroplastes rusci L. infesting fig trees. Annals of Agricultural Science (Cairo) 46: 355-364.
Salama, H.S. and Hamdy, M.K. 1974. Studies on populations on two scale insects infesting fig trees in Egypt (Coccoidea). Zeitschrift für Angewandte Entomologie 75: 200-204.