Diversity and abundance of leafhoppers in Canadian vineyards

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.

Diversity of Planthoppers (Hemiptera: Delphacidae) on Maize Crops and Edge Grasses in Mexico

Delphacid planthoppers (Hemiptera: Delphacidae) are a group of economically important sap-feeding insects that vector plant pathogens and are pests of crops, such as maize, wheat, and rice. This study was conducted to evaluate planthopper diversity, abundance, and the presence of potential vectors on maize crops and associated edge grass habitats. In Jalisco, west-central Mexico, delphacids were sampled using a sweep net in two different habitats (with and without irrigation) during the dry and rainy seasons of 2013 and 2014. A total of 5,621 specimens were collected and nine species were identified: Metadelphax propinqua (Fieber), Delphacodes koebelei Muir and Giffard, Delphacodes arcuata Beamer, Sogatella kolophon (Kirkaldy), Syndelphax fulvidorsum (Metcalf), Chionomus balboae (Muir & Giffard), Toya idonea (Beamer), Syndelphax humilis (Van Duzee), and Tagosodes cubanus (Crawford) (Hemiptera: Delphacidae), all belonging to the tribe Delphacini (Delphacinae). A high diversity of delphacids was found in the edge grasses during the dry season and rainy season. Planthopper abundance was higher in the edge grasses than in the maize fields during the rainy season. The most abundant species was M. propinqua representing 67.5% of the specimens collected. Populations of M. propinqua in edge grasses peaked during the dry season in December and January. Metadelphax propinqua, S. kolophon, and T. cubanus are known to be potential plant pathogen vectors.