A leaf miner is any one of numerous species of

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...

s in which the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

l stage lives in, and eats, the

leaf A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ...

tissue of plants. The vast majority of leaf-mining insects are

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

s ( Lepidoptera), sawflies ( Symphyta, the mother clade of

wasp A wasp is any insect of the narrow-waisted suborder Apocrita of the order Hymenoptera which is neither a bee nor an ant; this excludes the broad-waisted sawflies (Symphyta), which look somewhat like wasps, but are in a separate suborder ...

s), and flies ( Diptera). Some

beetle Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...

s also exhibit this behavior. Like woodboring beetles, leaf miners are protected from many predators and plant defenses by feeding within the tissues of the leaves, selectively eating only the layers that have the least amount of

cellulose Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wa ...

. When attacking '' Quercus robur'' (English oak), they also selectively feed on tissues containing lower levels of tannin, a deterrent chemical produced in great abundance by the tree. The pattern of the feeding tunnel and the layer of the leaf being mined is often diagnostic of the insect responsible, sometimes even to

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriat ...

level. The mine often contains

frass Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the ...

, or droppings, and the pattern of frass deposition, mine shape, and host plant identity are useful to determine the species and

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ...

of the leaf miner. Some mining insects feed in other parts of a plant, such as the surface of a

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in partic ...

or the petal of a flower. It has been suggested that some patterns of leaf variegation may be part of a defensive strategy employed by plants to deceive adult leaf miners into thinking that a leaf has already been preyed upon.

Leaf-mining species

One common leaf-mining species in New Zealand is '' Scaptomyza flava.'' The species is particularly problematic for plants in the family Brassiceae, more commonly known as mustard plants.

Relationship with humans

Leaf miners are regarded as pests by many farmers and gardeners as they can cause damage to

agricultural crops A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponics ...

and

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

plants, and can be difficult to control with insecticide sprays as they are protected inside the plant's leaves. Spraying the infected plants with

spinosad Spinosad is an insecticide based on chemical compounds found in the bacterial species '' Saccharopolyspora spinosa''. The genus ''Saccharopolyspora'' was discovered in 1985 in isolates from crushed sugarcane. The bacteria produce yellowish-pink ae ...

, an organic insecticide, can control some leaf miners. Spinosad does not kill on contact and must be ingested by the leaf miner. Two or three applications may be required in a season. However, this will have harmful ecological effects, especially if sprayed when bees or other beneficial arthropods are present. Leaf miner infection of crops can be reduced or prevented by planting trap crops near the plants to be protected. For example, lambsquarter and columbine 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. Phyllocnistis magnoliella caterpillar

References

External links

British leafminers
- many of which are distributed widely across Europe.
The leaf and stem mines of British flies and other insects
Includes illustrated keys for identification of mines by host-plant genus and detailed descriptions of over 900 species along with their distribution in Great Britain and Northern Ireland and elsewhere.
Leafminers of Europe
- covers over 1800 leafmining insect species.

on the UF / IFAS Featured Creatures Web site
''Liriomyza trifolii'', American serpentine leafminer
Center for Invasive Species Research page on Citrus Leaf Miner {{Authority control Agricultural pest insects Folivores Leaf miners

Leaf-mining species

Relationship with humans

See also

References

External links