Leaf miner

From Wikipedia, the free encyclopedia

Leaf miner damage to a horse chestnut tree

Leaf miners are insect larvae that live within leaf tissue. Many cause damage to garden plants and crops.

Like wood borers, leaf miners are difficult to control as they are protected from insecticide sprays and plant defenses by feeding within the tissues of the leaves themselves, selectively eating only the layers that have the least amount of cellulose. In attacking Quercus robur they also selectively feed on tissues containing low tannin levels, which the tree has produced in greater abundance as a defence.^[1] The precise pattern formed by the feeding tunnel is very often diagnostic for which kind of insect is responsible, sometimes even to genus level. The mine often contains frass, or droppings, and the pattern of frass deposition, mine shape and host plant identity are useful to determine the species of leaf miner. The vast majority of leaf-mining insects are moths (Lepidoptera) and flies (Diptera), though some beetles and wasps also exhibit this behavior. A few mining insects utilise other parts of a plant, such as the surface of a fruit.

British leafminers is an excellent resource on the British leaf mining fauna, many of which are distributed widely across Europe.

Leaf with leaf miner damage

[edit] Treatment

Leaf miner infection can be reduced or prevented by planting trap crops near the plants to be protected. For example, lambsquarter, columbine, and velvetleaf will distract leaf miners, drawing them to those plants and therefore reducing the incidence of attack on nearby crops. This is a method of companion planting.