A Comprehensive Review of the Coffee Leaf Miner Leucoptera coffeella (Lepidoptera: Lyonetiidae)—A Major Pest for the Coffee Crop in Brazil and Others Neotropical Countries

The coffee leaf miner (CLM) Leucoptera coffeella moth is a major threat to coffee production. Insect damage is related to the feeding behavior of the larvae on the leaf. During the immature life stages, the insect feeds in the mesophyll triggering necrosis and causing loss of photosynthetic capacity, defoliation and significant yield loss to coffee crops. Chemical control is used to support the coffee production chain, though market requirements move toward conscious consumption claiming for more sustainable methods. In this overview, we discuss aspects about the CLM concerning biology, history, geographical distribution, economic impacts, and the most relevant control strategies in progress. Insights to develop an integrated approach for a safer and eco-friendly control of the CLM are discussed here, including bio-extracts, nanotechnology, pheromones, and tolerant cultivars.

From Basic to Applied Knowledge: Larval Development and Sex Morphology to Control Leucoptera coffeella (Lepidoptera: Lyonetiidae)

The coffee leaf miner Leucoptera coffeella (Guérin-Mèneville & Perrottet), is a key pest in coffee producing countries. During their development, the larvae feed on the palisade parenchyma of the leaves forming mines. As a result, the photosynthetic area of the plant decreases, affecting coffee production. Despite the severity of the damage caused by coffee leaf miner (CLM), morphological aspects of the larval development and the adult genitalia remain unknown. It is important to identify more susceptible targets to an efficient and narrow control by natural or synthetic approaches, relies on determining the larval instars. Equally important is the sexing of the adult, in experiments aiming efficient ways to control CLM, as the study of pheromone-based control methods. This work presents the first morphological description of the four larval instars and the adult genitalia of L. coffeella. In each larval instar, we measured the Mean ± SD (mm) of the cephalic capsules (1st 0,14±0,03; 2nd 0,25±0,04; 3rd 0,32±0,03; 4th 0,42±0,03) and observed the following morphological details: primary setae, prolegs, crochets and ecdysial line of the cephalic capsule. In the adults, we observed the sexual structures present in both genitalia: male - bulbus ejaculatorius, valva, anellus, gnathos and aedeagus and female - ovipositor, sclerite and corpus bursae. The dissection of the adult specimens confirmed that the external morphology corresponds to the correct sex attribution in CLM adults. These results may support innovative and improved control strategies for CLM Integrated Pest Management (IPM).

A Comprehensive Review of the Coffee Leaf Miner Leucoptera Coffeella (Lepidoptera: Lyonetiidae), With Special Regard to Neotropical Impacts, Pest Management and Control

The coffee leaf miner (CLM) Leucoptera coffeella moth is a major threat to coffee production. Insect damage is related to the feeding behavior of the larvae on the leaf. During the immature life stages, the insect feeds in the mesophyll, triggering necrosis and causing loss of photosynthetic capacity, defoliation, and significant yield loss to coffee crops. Chemical control is mandatory to sustain the coffee production chain, though market requirements move towards conscious consumption, claiming for more sustainable methods. In this overview, we discuss aspects about the CLM concerning biology, history, geographical distribution, economic impacts, and the most relevant control strategies in progress. Insights to develop an integrate approach for a safer and eco-friendly control of the CLM are discussed, including bio-extracts, nanotechnology, pheromones, and tolerant cultivars.

Profile of Coffee Crops and Management of the Neotropical Coffee Leaf Miner, Leucoptera coffeella

The Neotropical coffee leaf miner is a key coffee pest and in the state of Bahia, one of the major coffee-producing states in the country. The insect finds favorable conditions for its development, causing production losses and intensive use of insecticides. Thus, the objective of the study was to analyze aspects of the profile of coffee crops and the management of the leaf miner, including the use of insecticide for the western and highland regions of Bahia. Data were obtained through questionnaires applied to coffee growers and/or production technicians and included information on the total area, area with coffee, and native vegetation, type of cultivation, cultivars, pest monitoring, methods of control and use, insecticide rotation, and doses used. Descriptive statistical analysis, principal component analysis (PCA), and canonical correlations indicated differences between farm size, and areas with coffee and native vegetation. Chemical pest control prevails as a management strategy in all farms. The results are important for managing the coffee leaf miner while providing an overview and diagnosis of insecticide use in coffee production in the state of Bahia. An increase in the application of systemic insecticides took place in recent years, similarly (same active ingredients) among most coffee growers. This fact increases the risk of selecting populations resistant to insecticides, compromising the management of the leaf miner in the regions.

Area-Wide Survey of Chlorantraniliprole Resistance and Control Failure Likelihood of the Neotropical Coffee Leaf Miner Leucoptera coffeella (Lepidoptera: Lyonetiidae)

The Neotropical coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842), is a key pest species of unshaded coffee plantations in Neotropical America, particularly in Brazil, where pest management involves intensive insecticide use. As a consequence, problems of resistance to conventional insecticides are frequent, and more recently developed insecticide molecules, such as diamide insecticides, are at risk of becoming ineffective. Thus, a survey of resistance to the diamide insecticide chlorantraniliprole was carried out in high-yield coffee-producing areas in the State of Bahia, Brazil. The likelihood of control failure with this insecticide was also assessed. Spatial dependence among the insect sampling sites was assessed and spatial mapping of chlorantraniliprole resistance and risk of control failure was carried out. The frequency of chlorantraniliprole resistant populations was high (34 out of 40 populations, or 85%), particularly in western Bahia, where 94% of the populations were resistant. Resistance levels ranged from low (<10-fold) to moderate (between 10- and 40-fold) with more serious instances occurring in western Bahia. This results in lower chlorantraniliprole efficacy among these populations, with a higher risk of control failure and exhibiting spatial dependence. These findings invite attention to problems with the intensive use of this relatively recent insecticide and demand management attention, but they suggest that local, farm-based management efforts are likely to be the most effective actions against resistance problems in this pest species.