Effect of Weed Management on the Parasitoid Community in Mediterranean Vineyards

Abstract

Enriching agroecosystems with non-crop vegetation is a popular strategy for conservation biocontrol. In vineyards, the effects of specific seeded or planted cover crops on natural enemies are well-studied, whereas conserving spontaneously developing weeds received less attention. We compared parasitoid communities between matched pairs of vineyard plots in northern Israel, differing in weed management practices: “herbicide”, repeated herbicide applications vs. “ground cover”, maintaining resident weeds and trimming them when needed. Using suction sampling, we assessed the parasitoids’ abundance, richness, and composition during three grape-growing seasons. Ground cover plots had greater parasitoid abundances and cumulative species richness than herbicide-treated plots, possibly because of their higher vegetation cover and richness. Dominant parasitoid species varied in their magnitude and direction of response to weed management. Their responses seem to combine tracking of host distributions with attraction to additional vegetation-provided resources. Parasitoid community composition was mildly yet significantly influenced by weed management, while season, year, and habitat (weeds vs. vine) had stronger effects. Vineyard weeds thus support local biocontrol agents and provide additional previously demonstrated benefits (e.g., soil conservation, lower agrochemical exposure) but might also attract some crop pests. When the benefits outweigh this risk, weed conservation seems a promising step towards more sustainable agricultural management.

Enhancement of the Diversity of Pollinators and Beneficial Insects in Intensively Managed Vineyards

“…Furthermore, the enhancement of insect biodiversity due to cover plants may play an important role as a natural biological control. Therefore, its use is also recommended as an Integrated Pest Management (IPM) tool to balance and eventually reduces the long-term pest populations increasing the natural enemies' community [62,[66][67][68][69]. Our results showed that within the most abundant genera were Coccinella and Chrysoperla, who are predators of aphids, and Sphaerophoria, who perform both pollination and predation functions.…”

Parasitoids ofLobesia botrana(Lepidoptera: Tortricidae) in the Douro Demarcated Region vineyards and the prospects for enhancing conservation biological control

“…The importance of non-crop vegetation or soil cover vegetation for providing resources to parasitoids, such as shelter, overwintering habitat, nectar, pollen, and alternate hosts or preys, have been reported elsewhere by several authors (e.g., Thomson and Hoffmann, 2009; Thomson et al ., 2010; Gaigher et al ., 2015; Smith et al ., 2015; Daane et al ., 2018; Shapira et al ., 2018; Segoli et al ., 2020; Möller et al ., 2021).…”

METABARCODING IN DIET ASSESSMENT OF ADULT PARASITOID SPECIES, Dolichogenidea metesae (HYMENOPTERA: BRACONIDAE) TOWARDS ITS CONSERVATION AND MANAGEMENT IN THE OIL PALM PLANTATION

“…Failure to follow the GAP code of practice (CoP) had resulted in a high use of chemical pesticides, which had a very significant adverse impact on weed diversity (Aini et al, 2007). According to Möller et al (2021), the abundance of parasitoids was higher in plots with a good ground cover compared to plots treated with herbicides. Wood and Norman (2019b) and Wood et al (1974) also reported that the application of chemicals had consequently disrupted the natural enemies of M. plana in the plantation habitats.…”