Time for coffee and tea
Coffee pests: leafminer (Leucoptera coffeella)
The coffee Leaf Miner (Leucoptera coffeella) is a pest of coffee trees in the neotropical coffee producing countries; Coffee Leaf Miners are the major pest of coffee in Brazil. It is the coffee leaves that are attacked by the caterpillars of the Leaf Miner moth, this results in death of the coffee leaf. This affects the crop of the coffee tree in various ways. firstly the tree will not live as long, secondly there is a drop in the yield of the plant, and thirdly the quality of the coffee beans themselves are much reduced.
It is estimated that the loss in yield due to infestication by Leaf Miner moths is around 40% in Brazil; this can increase to as much as 80% in areas where the Leaf Miner larvae are not controlled, and the coffee plants become infesticated with the pest.
The Coffee Leaf Miner is usually controlled by insecticides, unfortunately this often leads to secondary outbreaks; additionally the Coffee Leaf Miner is becoming resistant to the insecticides that are used to control the pest in Brazil. This in turn leads to a vicious circle where more and more insecticide is used by the farmers to try to control the creature. This is neither healthy nor a good long term strategy for the control of coffee pests.
There are known natural pests of the Coffee Leaf Miner but little is known about how/if they can control the pest. Another thing that has a great impact upon the quantity of leaf miners is the weather; They are known to be much reduced in number during times of rainfall, and increase dramatically during dry spells. Another thing that is likely to have an impact upon the coffee pest are plant defence mechanisms and nutrients.
The Coffee Leaf Miner moth only lays its eggs on coffee plants. It normally lays eggs on the upper leaf surface, either singly or in small groups. the larvae of the leafminer hatch after about 7 to 12 days and starts to feed on the palisade parenchyma of the coffee leaf. The larvae will remain feeding on one leaf as they are not able to travel from one leaf to another. The larvae stage varies from 9 up to 40 days. Pupation than takes place on the lower leaf surfaces and metamorphosis occurs, this can last anything from 4 to 26 days. The moth that emerges is white in colour and about 2 mm long. The moth lives for about two weeks. During a year, up to twelve unbroken and overlapping generations can occur in the coffee plantations.
To better understand the interactions between the Coffee Leaf Miner and coffee plants, Pereira et al from the Federal University of Vicosa in Brazil analysed seasonal mortality factors of the pest in a 3 hectare Coffea arabica plantation in Brazil. The results of their findings are reported in the next section of this coffee leaf miner pest article.
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