Submitted to: Cornell University Press
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/2/2002
Publication Date: 12/10/2004
Citation: Gullan, P.J., Miller, D.R., Cook, L.G. 2004. Gall-inducing scale insects. Science Publishers Inc. New Hampshire, USA. 159-229.
Interpretive Summary: Scale insects cause several billion of dollars in damage and control costs each year and new invasive species are introduced into the United States annually. Understanding the biology and classification of scales can be highly beneficial in finding methods to control and manage them without expending major costs.n This paper examines the species of scale insects that form galls on plants including several that are pests of ornamentals and one that is being used as a biological control agent of a weed. The results will be of use to ecologists, research scientists, biological control specialists, and horticulturalists.
Technical Abstract: The scale insects or coccoids (Hemiptera: Sternorrhyncha: Coccoidea) are morphologically specialized plant parasites that mostly either live under a protective cover derived from their waxy secretions and/or old exuviae or live concealed by plant tissue, including within galls of a diversity of forms. There are more than 700 described species of scale insects of which about 230 species (or about 280 if undescribedd taxa are included) induce galls that range in complexity from simple pits and foliage distortions to woody, enclosed structures of elaborate morphology. Only 10 of the twenty or more families of scale insects induce galls and the highest proportion of galling taxa (approximately 45% of described species and 57% of recognized species) belong to the Eriococcidae. Almost all eriococcid gallers occur in Australia, where their major host-plant family is the Myrtaceae. Gall-inducing Pseudococcidae have radiated in Hawaii. For other coccoid families, the gall-inducing taxa are scattered among diverse genera and show no particular patterns of distribution or host use except that gallicolus Lecanodiaspididae are most common in Australia.