Effects of Host Plant on the Predator-Prey Cycle of Zetzellia mali (Acari: Stigmaeidae) and Its Prey

• DOI: 10.1093/ee/13.1.65
• Publication Date: 2015-01-14T00:57:08Z
• Authors: Miguel A. Santos
• Keywords: 0106 biological sciences; 15. Life on land; 01 natural sciences

Population counts of Zetzellia mali (Ewing) and its prey, Aculus schlechtendali (Nalepa), Panonychus ulmi (Koch), and Tetranychus urticae Koch on ‘Delicious’ apple trees were studied to determine what factor(s) regulates predator-prey oscillations. Four interrelated factors were considered: leaf nutrients, soil moisture, leaf conditioning, and growth of the apple leaves. It was observed that prey populations initially increased when the trees added new leaves. Soon thereafter, the predator, Z. mali , increased its numerical response. The combined effect of predation and leaf conditioning caused a decline in the prey populations. With fewer prey available, the numerical response of Z. mali decreased. Leaf nutrients, soil moisture, and leaf conditioning affected the number of phytophagous mites on the trees. The overall predator-prey cycle, however, was not affected.