Seasonal mortality factors of the coffee leafminer,Leucoptera coffeella

Abstract

Seasonal population fluctuation of the coffee leafminer, Leucoptera coffeella (Guérin-Méneville & Perrottet) (Lepidoptera: Lyonetiidae), led to an investigation of its natural mortality factors during the rainy season when the population level is low and during the dry season when population peaks occur. Life-table data were collected from insecticide-free plots within a 3 ha coffee plantation on the upper, medium and lower canopy. Leafminer mortality was similar among the canopy parts but varied in the two seasons studied. During the rainy season, the generational mortality averaged 94.3%, with 50.2, 33.7 and 10.4% occurring during egg, larval and pupal stages, respectively. During the dry season, total mortality was 89%, with 13.2, 61.0 and 14.8% occurring during egg, larval and pupal stages, respectively. Marginal mortality rates during the rainy season were highest for physiological disturbances, rainfall and egg inviability; but, in the dry season, they were highest for predaceous wasps, physiological disturbances and parasitoids. Egg and larval stages accounted for most of the mortality variation in the rainy season, while the combination of larval and pupal mortality better described the generational mortality in the dry season. Variation in mortality during the rainy season was primarily associated with egg inviability, rainfall and parasitoids. In contrast, predatory wasps and physiological disturbances were the main factors associated with mortality variation during the dry season. These results suggest that weather conditions, natural enemies and plant quality attributes are the main determinants of the population dynamics of L. coffeella.

Spatial and temporal dynamics of coffee-leaf-miner and predatory wasps in organic coffee field in formation

“…Previous studies have addressed the influences of environmental (rainfall, relative humidity, ambient temperature, etc.) on coffeeleaf-miner population dynamics (REIS et al, 2006;PEREIRA et al, 2007, LOMELÍ-FLORES, 2010. For example, PEREIRA et al (2007) have suggested that heavy rain was the main source of coffee-leaf-miner mortality, particularly during the rainy season.…”

Toxicity of organic farming‑compatible products to the coffee leaf miner

“…The experiment was carried out at the Experimental Station of Epamig, in the municipality of Oratórios (20°24'S, 42°48'W), MG, Brazil, from May to August 2007, during part of the region's dry season and under favorable climate conditions for L. coffeella (Pereira et al, 2007). Five lime sulphur concentrations (0.5, 1.0, 1.5, 2.0, and 2.5%, v/v) were applied either biweekly or monthly.…”

“…These measures include the use of nonsynthetic products approved by national organic standard organizations. In Brazil, organic coffee growers often spray a large array of organic farming-compatible products aiming at controlling the coffee leaf miner Leucoptera coffeella Guérin-Mèneville (Lepidoptera: Lyonetiidae), one of the key coffee pests (Reis et al, 2002;Pereira et al, 2007). Among organic farming-compatible products used for organic coffee production are botanical extracts, biofertilizers, sulphur based products and Bordeaux mixture.…”

Efeitos de variáveis ambientais, irrigação e vespas predadoras sobre Leucoptera coffeella (Guérin-Méneville) (Lepidoptera: Lyonetiidae) no cafeeiro

“…Para a avaliação das densidades do bicho mineiro e das vespas predadoras contou-se o número de minas ativas (presença de larvas vivas do bicho mineiro) e o número de minas predadas (presença de rasgaduras ocasionadas pelas vespas predadoras nas faces adaxial e abaxial da folha) pelos principais gêneros de vespas predadoras de L. coffeella encontradas em cafeeiros nessa região, Mischocyttarus, Polistes, Protopolybia, Polybia, Brachygastra e Protonectarina (Pereira et al 2007). A contagem das minas ativas e predadas foi realizada através da abertura das minas com estilete metálico.…”