Leafminers

Leaf miners are those insects that consume leaves and needles from within the foliage of the host plant. Those found attacking deciduous plants are known as "leaf miners" while those attacking conifers are "needle miners". Here, they will be collectively referred to as leaf miners.

Leaf miners are found in many different insect orders, such as, lepidoptera (moths and butterflies), hymenoptera (leaf mining sawflies), coleoptera (the beetles), and diptera (the true flies). All of these are leaf miners while in the immature, or larval, stage of their life cycle. Depending on the species involved, some will pupate within the mined foliage while others emerge first and then pupate.

Feeding within foliage offers some protection from predators and parasites by being unseen. However, there are those beneficial insects that specialize in being parasites of leaf mining insects. Many of these parasites being from the hymenoptera (wasps).

Leaf miners may feed on the spongy mesophyll, palisade parenchyma cells and perhaps all but the upper and lower epidermis. Mines may be in the form of a blotch or may be more winding or serpentine. When many leaf miners are found within one leaf, mines may then coalesce into one large blotch-type mine.

Control of leaf miners, in general, is usually best achieved during the part of the life cycle when the insect is not within the host plant foliage.

Leaf miners index:
Arborvitae Leafminer
Birch Leafminer
Boxwood Leafminer

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