Impact of Host Plant Resistance and Coccinellid Predators on Cereal Aphid Abundance and Wheat Yield

• Published in: Asian journal of crop science Vol. 6; no. 3; p. 281
• Main Authors: Nyaanga, J G, Kamau, A W, Pathak, R S, Tuey, R K
• Format: Journal Article
• Language: English
• Published: 2014
• Subjects: Aphididae; Rhopalosiphum padi; Triticum aestivum
• ISSN: 1994-7879; 2077-2041
• DOI: 10.3923/ajcs.2014.281.288

Biological control and host plant resistance are key components of Integrated Pest Management (IPM). Little studies have however been done on their potential for integration in the management of cereal aphids in wheat. The impact of host plant resistance and coccinellid predators on cereal aphid population and wheat yield was therefore studied in outdoor cages. Two wheat varieties and two coccinellids predators Adonia variegeta and Chelomenes lunata were compared against a control. A mixed population of three cereal aphid species was inoculated onto wheat plants and newly emerged coccinellids were introduced in all plots except controls. Aphid counts were taken at five wheat growth stages. Repeated measure analysis indicated that there were significant differences in aphid counts between the cages with coccinellids and the control (F = 7.20; df 2, 12; MSE = 28; p<0.09) in 2008 and (F = 9.4; df2, 12; MSE = 19; p<0.09) in 2009. The aphid numbers in the control (13.7) were approximately twice those in cages with beetles (7). Coccinellids and the resistant wheat variety showed a positive interaction at flowering stage (F = 25.3; df60, 89; MSE = 3.9; p<0.01). Cages with coccinellids recorded more than 50% increase in wheat yield (F = 44; df 10, 17; MSE = 0.00004; p<0.001) in 2008 and (F = 57; df 10, 17; MSE = 0.000036; p<0.0001) in 2009 compared to the control. Wheat plant resistance and biological control could therefore be complementary strategies in IPM against cereal aphids.