Potential role of indigenous Coccinellidae in regulation of aphid populations in Central Arabia wheat fields

Abstract

Abstract Caged experiments were carried out for two seasons (1987–88 and 1988–89) to investigate the potentialities of indigenous Coccinellidae in regulating aphid populations in wheat fields of Central Saudi Arabia. The results indicated that the use of Coccinella undecimpunctata L., the predominant predator in Gassim, alone or in combination with Adonia variegata Goeze and C. novemnotata Hbrst. at similar ratios as found in the fields, can satisfactorily control wheat aphids in a confined environment. Yields obtained from such coccinellid‐treated wheat are not significantly different from those obtained from an uninfested control. Untreated aphid‐infested wheat resulted in lower yields in both seasons (an average of 30.9% less than the aphid‐free control for the two seasons). Head length and grain number per head were substantially lower in aphid‐infested untreated control than in the coccinellid and the aphid‐free treatments. Use of C. undecimpunctata alone or in combination with others resulted in inc...