''Dioryctria sylvestrella'', the new pine knot-horn or maritime pine borer, is a moth of the family Pyralidae. It is found in Europe, parts of Asia and North Africa. The adult is a small mottled brown and white insect with a wingspan of . The moth flies in a single generation from June to October and is a

pest Pest or The Pest may refer to: Science and medicine * Pest (organism), an animal or plant deemed to be detrimental to humans or human concerns ** Weed, a plant considered undesirable * Infectious disease, an illness resulting from an infection ** ...

of maritime pine and several other species of pine, on which the

caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...

s feed.

Description

Moths in the genus '' Dioryctria'' generally have forewings that are dark greyish-brown to black, with various white markings, chevrons and zigzag lines. ''Dioryctria sylvestrella'' has a wingspan of and is very similar in appearance to related species. This moth was first detected in Britain in 2001, and can be told from the three other species in the genus already there by the fact that the "subterminal line is generally smooth with a single waved kink tits mid-point, in the other three species this line is dentate from the mid-point to the dorsum".

Distribution and hosts

''Dioryctria sylvestrella'' occurs naturally in Europe, much of Asia and North Africa. It occurs as far north as the

Arctic Circle The Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at w ...

but is more common at lower latitudes, and this is where it does most damage. In Europe, it mainly infests the maritime pine ('' Pinus pinaster'') but it can feed on other species of pine, and on

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

. Other known hosts are '' P. caribaea'', '' P. halepensis'', '' P. kesiya'', '' P. merkusii'', '' P. nigra'' and '' P. pinea''. New shoots on trees that have been treated with fertiliser are more likely to be infested than unfertilised trees, and pruned trees are also targeted over non-pruned trees.

Life cycle

The adult moths are on the wing in southern Europe from about July to September. The female chooses fast-growing, vigorous host trees on which to lay its eggs. The larvae attack buds, shoots, cones, and young stems. Damaged tissue or sites attacked by the rust fungus ''

Endocronartium ''Endocronartium'' is a genus of rust fungi in the Cronartiaceae family. The genus contains three species found in Europe, North America, and Japan, that grow on ''Pinus A pine is any conifer tree or shrub in the genus ''Pinus'' () of the f ...

'' allow the larvae to enter the tissues and tunnel under the bark into the phloem. The larvae usually stay near where they hatched, but occasionally migrate to other parts of the tree. They pupate inside the mass of resin mixed with

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 G ...

which they produce.

Damage

The larvae of this moth are one of the main pests of maritime pine, an important plantation crop of the Mediterranean region where it is grown for timber and resin production as well as

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

stabilisation. Their boring activity causes large quantities of resin to flow from the wounds which weakens the tree and allows fungi and other pathogens to gain entry.

References

External links

waarneming.nl

''Dioryctria sylvestrella'' on UKMoths
{{Taxonbar, from=Q731828 sylvestrella Insect pests of temperate forests Moths of Africa Moths of Asia Moths of Europe Taxa named by Julius Theodor Christian Ratzeburg Moths described in 1840