Affiliation:
1. Departamento de Entomologia Universidade Federal de Lavras Lavras Minas Gerais 37200‐900 Brazil
2. Museu de Malacologia Prof. Maury Pinto de Oliveira Universidade Federal de Juiz de Fora Juiz de Fora Minas Gerais 36036‐330 Brazil
3. Departamento de Entomologia Universidade Federal de Viçosa Viçosa Minas Gerais 36570‐900 Brazil
Abstract
Abstract
Terrestrial gastropods (slugs and snails, Mollusca: Eupulmonata) are destructive pests of brassica crops. These organisms defoliate plants and contaminate the harvest, leading to reduced crop yield and marketability. Losses caused by molluscs have escalated in recent years in Brazil.
We aimed to determine the seasonal activity of gastropods in brassica fields and unravel the environmental variables associated with these dynamics. Gastropod abundance, assemblage and within‐plant distribution were also compared among Brassica oleracea cultivars (broccoli, cabbage and cauliflower).
Mild temperatures and rainy periods were found to coincide with gastropod peaks. Regression analyses confirmed a positive association of rainfall and humidity with gastropod abundance, whereas gastropod abundance increased with decreasing temperature. Deroceras laeve (Müller) (Agriolimacidae) and Bradybaena similaris (Férussac) (Bradybaenidae) were the most constant species. Mollusc abundance and assemblage differed amid B. oleracea cultivar; cabbage had the highest abundance and its species composition differed from broccoli and cauliflower. Slugs and snails were more concentrated on lower plant portions, regardless of the cultivar.
Management efforts should be reinforced in mild‐temperature and rainy periods to reduce damage by gastropods, and cabbage should be monitored more closely than other cultivars.
Funder
Conselho Nacional de Desenvolvimento Científico e Tecnológico
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Fundação de Amparo à Pesquisa do Estado de Minas Gerais
Subject
Insect Science,Agronomy and Crop Science,Forestry