''Dendroctonus terebrans'', the black turpentine beetle, is a species of bark beetle native to the eastern United States. Its larvae tunnel under the bark of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

trees, weakening and sometimes killing the trees.

Description

This is the largest bark beetle in the southeastern United States, with an adult length of . It is cylindrical, dark reddish-brown or black. The

prothorax The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum ( dorsal), the prosternum ( ventral), and the propleuron ( lateral) o ...

is narrower at the front than at the back and does not completely cover the head. The antennae are club-shaped, the front of the head is convex, and the tip of the abdomen is rounded. The larvae are creamy-white with orange-brown heads, and have no legs. When fully developed they are about in length.

Distribution

''Dendroctonus terebrans'' is native to

eastern United States The Eastern United States, commonly referred to as the American East, Eastern America, or simply the East, is the region of the United States to the east of the Mississippi River. In some cases the term may refer to a smaller area or the East C ...

where it attacks both native pines and exotic pine species. Its range extends from

New Hampshire New Hampshire is a state in the New England region of the northeastern United States. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Gulf of Maine to the east, and the Canadian province of Quebec to the nor ...

southwards through the coastal plain to

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

and westward to

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

and

Missouri Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...

. The red turpentine beetle (''Dendroctonus valens'') has a much wider distribution in the eastern United States, and the ranges of the two species overlap very little.

Life cycle

This beetle is strongly attracted to volatile chemicals produced by freshly cut pine stumps, and it will infest these as well as intact trees, in particular selecting trees that are stressed. The trees are often simultaneously attacked by certain species of engraver beetles (''Ips'' spp.) and the

southern pine beetle ''Dendroctonus frontalis'', the Southern Pine Beetle (also known as SPB), is a species of bark beetle native to the forests of southern United States, Mexico and Central America. The Southern Pine Beetle reddish brown to black exoskeleton and me ...

(''Dendroctonus frontalis''). ''Dendroctonus terebrans'' attacks pine trees near the base. A female beetle tunnels into the bark and has to overcome the

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on n ...

exuded by the tree as a defence. This oozing resin mixes with the wood dust and forms a pinkish "pitch tube" on the bark at the site of entry. If she successfully gains entry into the sapwood, the female spends about a fortnight excavating a gallery which typically is at first horizontal and then goes vertically downwards, often to below ground level. Here she is joined by a male and lays about a hundred eggs at one side of the gallery. The eggs hatch after ten to fourteen days and the larvae fan out, chewing their way side by side through the surface layers of the sapwood, creating a gallery packed full with the

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 ...

they produce. This gallery resembles that formed by the red turpentine beetle and the Mexican bark beetle ('' Dendroctonus rhizophagus''), which both feed on

, and the great spruce bark beetle (''Dendroctonus micans''), which feeds on spruce. When they have completed their development, the larvae tunnel away from each other individually and create

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in thei ...

tion chambers in which they pupate. When the adult insects emerge, they drill their way to the surface and disperse. In Florida, breeding takes place at any time of year, and there may be three overlapping generations. The beetle can act as a

vector Vector most often refers to: *Euclidean vector, a quantity with a magnitude and a direction *Vector (epidemiology), an agent that carries and transmits an infectious pathogen into another living organism Vector may also refer to: Mathematic ...

for the

blue stain fungus Blue stain fungi (also known as sap stain fungi) is a vague term including various fungi that cause dark staining in sapwood. The staining is most often blue, but could also be grey or black. Because the grouping is based solely on symptomatics, it ...

, carrying it from one tree to another. A European predatory beetle, '' Rhizophagus grandis'', that normally preys on the related great spruce bark beetle, has been found experimentally to be attracted to the frass produced by the black turpentine beetle larvae.

Biological control Biological control or biocontrol is a method of controlling pests, such as insects, mites, weeds, and plant diseases, using other organisms. It relies on predation, parasitism, herbivory, or other natural mechanisms, but typically also i ...

using this predator is being investigated, with a batch of beetles imported from

Belgium Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to th ...

being released in

Louisiana Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...

in 1988.

References

External links

Featured Creatures: ''Dendroctonus terebrans'', black turpentine beetle
UF / IFAS {{Taxonbar, from=Q30323182 Woodboring beetles Scolytinae Beetles of North America Beetles described in 1795