Spatio-temporal variation of strawberry aphid populations and their parasitoids

GRECO, NANCY; CINGOLANI, MARÍA F.

APPLIED ENTOMOLOGY AND ZOOLOGY

JAPAN SOC APPL ENTOMOL ZOOL

Año: 2018 vol. 53 p. 205 - 214

0003-6862

Aphids are common herbivores in strawberry that can reduce plant vigor and fruit quality and also transmit viruses. Aphid species prefer diverse plant organs, which represent particular habitats of different quality for aphids and natural enemies? populations? development. Different habitat units (young leaves, mature leaves, buds, flowers) of strawberry were sampled fortnightly during all seasons. Aphid and parasitoid species were recognized and counted. We identified seven aphid species, being Chaetosiphon fragaefolii, Aphis gossypii, and Macrosiphum euphorbiae the most abundant. During autumn, C. fragaefolli and M. euphorbiae were scarce and A. gossypii was denser on mature leaves, while during summer M. euphorbiae was absent. During winter, C. fragaefolii predominated on buds and young leaves, A. gossypii on flowers, and both species on mature leaves. During spring, C. fragaefolii was even more abundant on buds, A. gossypii predominated on mature leaves, and the three species were equally abundant on flowers and young leaves. Parasitoids emerged from A. gossypii, M. euphorbiae and Myzus persicae, but not from C. fragaefolii. Three Aphidius and two Aphelinus species were recovered. All parasitoid species emerged from A. gossypii, and hyperparasitoids emerged only from this aphid. Aphis gossypii parasitism on mature leaves was markedly higher in winter and summer than in autumn and spring. Parasitism of A. gossypii was independent of its density, and the number of parasitized aphids was never higher than 6. Our results contribute to defining the most appropriate sample unit to estimate aphid density of different species and provide information about seasonal natural parasitism.