Influence of Vineyard Inter-Row Groundcover Vegetation Management on Arthropod Assemblages in the Vineyards of North-Eastern Italy

Influence of Vineyard Inter-Row Management on Grapevine Leafhoppers and Their Natural Enemies

Inter-row management in vineyards can influence the abundance of grapevine pests and their natural enemies. In 2013-2015, in a vineyard in northeastern Italy, the influence of two vineyard inter-row management strategies (i.e., alternate mowing, AM, and periodical tillage, PT) on the population dynamics of grapevine leafhoppers Hebata vitis and Zygina rhamni and their natural enemies, the mymarid Anagrus atomus and spiders (Araneae), and other hymenopteran parasitoids, were studied with different survey approaches. The infestations of both leafhoppers were lower in AM than PT due to the reduced leafhopper oviposition and higher nymph mortality in AM. This occurred although leafhopper egg parasitization by A. atomus was greater in PT than AM according to a density-dependent relationship with the leafhopper egg amount. Hymenopteran parasitoids other than A. atomus were the most abundant in AM, probably due to the higher availability of nectar and pollen than in PM. The significantly higher population densities of hunting spiders in AM than PT can be associated with the higher predation of leafhopper nymphs. Therefore, the study demonstrated that the alternate mowing of vineyard inter-rows enhances the abundance of natural enemies, such as spiders and hymenopteran parasitoids, and can contribute to grapevine leafhopper pest control.

Side Effects of Kaolin and Bunch-Zone Leaf Removal on Generalist Predators in Vineyards

In vineyards, kaolin application and bunch-zone leaf removal (LR) were effective in the control of leafhoppers and Lobesia botrana, but their side effects on generalist predators are still poorly understood. In north-eastern Italian vineyards, the impact of kaolin and LR on species and functional diversity of spiders, as well as the abundance of spiders and generalist predatory insects, was assessed in one vineyard for two consecutive years and in two vineyards for one year. The ecological indices of the spider community were never influenced by kaolin and only in one case were they influenced by LR. At the spider family level, kaolin reduced the abundance of Araneidae, Oxypidae and Salticidae, but only in single cases. In single cases, kaolin reduced the amount of Orius sp. anthocorids and increased that of Scymninae coccinellids, whereas LR increased the amount of Aeolothrips sp. The moderate use of kaolin and the application of LR had negligible and inconsistent impacts on generalist predatory arthropods in vineyards and were therefore, compatible with IPM strategies.

Biodiversity in a Cool-Climate Vineyard: A Case Study from Quebec

Simple Summary

This paper documents research activities related to the biodiversity of the l’Orpailleur vineyard located in Dunham (Quebec, Canada) from 1997 to 2021. In a first phase starting in 1997, the biodiversity of insecticide-free and insecticide-treated parts of the vineyard was determined for several taxa. In a second phase starting 2004, entomological problems were addressed on an ad hoc basis as they unfolded. For example, at the request of viticulturists, research was conducted on the tarnished plant bug (Lygus lineolaris-Miridae) and on the system phytoplasmas/cicadellids/grapevines. In a third phase starting in 2014, management of plants between grapevine rows and areas adjacent to the vineyard was carried out to increase biodiversity with the aim to achieve arthropod control with minimal insecticide and acaricide use. To address the advent of a new pest, such as the Japanese beetle (Popillia japonica-Scarabaeidae), a biocontrol program based on the parasite Istocheta aldrichi (Tachinidae) was initiated.

Abstract

In Quebec (Canada), viticulture has experienced steady growth in the last 35 years in terms of surfaces cultivated and value, although it is practiced in climatic conditions at the edge of what is considered a cool-climate area. This case study documents biodiversity studies conducted at the l’Orpailleur vineyard (Dunham, QC, Canada) from 1997 to 2021. In a first phase starting in 1997, the biodiversity of insecticide-free and insecticide-treated plots was determined for the taxa Scarabaeidae, Curculionidae, Chrysomelidae, Cicadellidae, Acari and Aranae. This step provided a baseline allowing to identify key arthropods. In a second phase starting in 2004, entomological issues were addressed on an ad hoc basis. In 2014, a third phase began with a perspective of sustainability and management of plant diversity in the vineyard to conserve natural enemies. Because of increased Japanese beetle (Popillia japonica-Scarabaeidae) populations and threats to vineyards, a biocontrol program based on the parasitoid Istocheta aldrichi (Tachinidae) was initiated. The unusually fast development of grapevines during the growing season, selection of flowering species, as well as selected arthropods associated with these flowering species, will be illustrated. Periodic update of protection programs will be required to address future challenges associated with climate change scenarios and world trade.

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

Simple Summary

The continuous intensification of agricultural production has resulted in higher yields and more yield security. However, these achievements went along with the substitution of heterogeneous agricultural landscapes by homogeneous ones with poor crop diversity, short crop rotations, and thanks to the high efficacy of modern herbicides and also to minimum in-crop diversity. A severe increase in plot size led to the elimination of ecologically valuable structural elements that had provided floral resources and nesting sites. Over the few last decades, several studies have been conducted to try to find solutions against insect decline and to preserve biodiversity. In the present study, the integration of cover plants between the lines of the vineyards to enhance biodiversity is shown. The benefits of the cover plants use are presented based on the results achieved on five intensive wine farms in Spain. Our findings suggest that the use of cover plants provide a wide range of enhancements in the insect community with a significant increase both in the number of species and the number of individuals showing an important influence over time, which would tend to have a significant conservation impact thanks to its effect as a reservoir of species.

Abstract

(1) Modern, intensive agricultural practices have been attributed to the loss of insect biodiversity and abundance in agroecosystems for the last 80 years. The aim of this work is to test whether there are statistically significant differences in insect abundance between different zones and over time on the vineyard field. (2) The study was carried out in five intensive wine farms in Spain over a three-year period (2013–2015). Each field was divided into two zones, one where cover plants were planted, and another remained unchanged (without cover). (3) A clear trend to increase the average number of insect species and individuals throughout the years in all farms was observed. Moreover, the zones with cover plants showed a significant difference with respect to the zones without. (4) The use of permanent cover plants allows creating areas of refuge for the insects favouring their conservation and reducing the agriculture impact in the insect decline.