Do hedgerows influence the natural biological control of woolly apple aphids in orchards?

• Published in: Journal of pest science Vol. 93; no. 1; pp. 219 - 234
• Main Authors: Peñalver-Cruz, Ainara, Alvarez, Diego, Lavandero, Blas
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2020; Springer Nature B.V
• Subjects: Abundance; Agricultural production; Agriculture; Aphididae; Apples; Biodiversity; Biological control; Biomedical and Life Sciences; Colonization; Crops; Ecology; Entomology; Forestry; Fruit trees; Fruits; Growth rate; Hedgerows; Insects; Life Sciences; Natural enemies; Orchards; Original Paper; Parasitism; Parasitoids; Plant Pathology; Plant Sciences; Population growth; Predators; Seasons; Spiders; Vegetation; Apple orchards; Generalist predators; Parasitism; Woolly apple aphid
• ISSN: 1612-4758; 1612-4766
• DOI: 10.1007/s10340-019-01153-1

The provision of refuges for natural enemies could be a key aspect for the management of the woolly apple aphid [
Eriosoma lanigerum
(Hausmann, 1802)] (Hemiptera: Aphididae) in apple orchards. The present study assesses the effects of
Pyracantha coccinea
(Rosaceae) (firethorn) adjacent to apple orchards as this extra-orchard habitat would positively affect the abundance of natural enemies and control of
E. lanigerum
. Abundances were evaluated for the pest, the parasitoid,
Aphelinus mali
(Haldeman, 1851) (Hymenoptera: Aphelinidae) (during two seasons) and generalist predators (only during the second season). The assessments were conducted at different distances from
P. coccinea
located at the edge of the apple orchards. Additionally, parasitism rates by
A. mali
were examined using a categorical and two quantitative methods. Results indicate that
P. coccinea
hedges promoted an early colonization by
A. mali
in apple orchards especially during the first season. However, parasitism rates by
A. mali
were not affected at the beginning of the season, but as the season progressed, the rates increased on the apple trees in comparison with the hedges. Additionally, during the second season, the interaction between certain natural enemies had a stronger effect on the population growth rates of
E. lanigerum
in orchards with
P. coccinea
compared to control orchards. Based on these results, we conclude that
P. coccinea
hedges may promote the early colonization by
A. mali
in the orchards and have a positive effect on the abundance of spiders, but had no effect on coccinelid, carabids, earwigs and syrphids.