The effects of weed strips on aphids and aphidophagous predators in an apple orchard

Abstract

Selected weeds were used to attract antagonists of apple aphids in an apple orchard near Berne, Switzerland. In the year before the experiment, in 1991, the apple aphids Dysaphis plantaginea (Pass.) and Aphis pomi (DeGeer) and aphidophagous predators were homogenously distributed in the orchard. In April 1992, weed strips were sown between tree rows and along the border parallel to the first and the last row of trees in one part (the other part served as control). In both parts of the orchard, randomly chosen trees were controlled visually in weekly intervals in 1992 and 1993. During flowering of weeds more aphidophagous predators were observed on the apple trees within the strip-sown area than in the control area. The most abundant and permanent aphidophagous predators were spiders, predaceous Heteroptera, Coccinellidae, and Chrysopidae. Both species of aphids were significantly less abundant in the area with weed strips than in the control area during the vegetation period. The effects of the weed strips on aphidophagous predators, and those of predators on aphids, are discussed.

The effects of plant cover on population of pear psylla (Cacopsylla pyricola) and its predators

“…Thus, plant cover had nil effect on the pear psyllid control. Some studies have reported a decrease in herbivore density in the presence of ground cover vegetation (AguilarFenollosa et al, 2011;Altieri and Schmidt, 1986;Beizhou et al, 2011;Irvin et al, 2006;Pfammatter and Vuignier, 1998;Rieux et al, 1999;Wyss, 1995;Wyss et al, 1995) et al, 1982;Meyer, 1990a, 1990b;Spellman et al, 2006). All of these studies have shown that selection of the plant cover species in the orchard is important in preventing increased pest population.…”

Effect of Achillea millefolium Strips and Essential Oil on the European Apple Sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidea)

“…However, the literature provides contrasting results: a lower abundance of herbivores and a higher abundance of parasitoids and predators [24][25][26][27], a higher abundance of herbivorous insects [28], or no differences between managed and control habitats [29,30].…”

Peran Tumbuhan Berbunga Sebagai Media Konservasi Artropoda Musuh Alami (The Role of Flowering Plants in Conserving Arthropod Natural Enemies)

“…Penanaman gulma berbunga di antara baris atau di bagian tepi kebun apel meningkatkan jumlah predator afid jika dibandingkan dengan kebun tanpa gulma (Wyss, 1995). Sebelumnya Halley dan Hogue (1990) juga membuktikan bahwa penambahan tumbuhan berbunga di sekitar perkebunan apel dapat menurunkan populasi hama, khususnya kutu afid.…”