1961/07/01 by B. R. Bartlett · 1 citation
Agricultural and Biological Sciences · #Research on scale insects #Insect-Plant Interactions and Control #Phytoplasmas and Hemiptera pathogens
paper · doi:10.1093/aesa/54.4.543
The ability of ants to increase the abundance of certain Coccidae on citrus is recognized in the practical control of these pests in California. The role of ants in the collection and colonization of foreign parasites of lecaniine scale insects is discussed. In ant-attended lecaniine scale infestations, certain parasite species are little influenced by ants while others are strongly suppressed. Following ant removal from infestations of Saissetia oleae (Bern.) and Coccus hesperidium, the pattern of parasite dominance showed that Metaphycus helvolus Comp. and M. luteolus Timb., although not the most abundant species present, were responsible for the subsequent rapid decrease of their respective scale hosts. In the laboratory, in the absence of parasites, heavy accumulations of honeydew may cause a slight retardation in the growth rate and a decrease in survival of some scale insects. The Argentine ant, Iridomyrmex humilis Mayr, possesses no unique capacity for physiological stimulation of scale development and survival beyond that provided by mechanical removal of accumulated honeydew by water-washing. Ant toleration was shown to be associated with the rapidity of oviposition by some parasites. In the exceptions to this rule, certain parasites requiring a long period for egg deposition were less sensitive to nearby moving objects and therefore little influenced by the presence of ants, while other species with short oviposition periods were easily disturbed by any nearby moving objects and therefore would not tolerate the presence of ants. Disturbance by ants resulted in from 27.4% to 98.4% reduction in parasitization, depending on the parasite species. A list of ant association responses of some common predators suggests the degree to which predation may be suppressed by ants.