The cottonwood borer (''Plectrodera scalator'') is a species of
longhorn beetle found in the
United States east of the
Rocky Mountains that feeds on
cottonwood trees. It is one of the largest insects in North America, with lengths reaching and widths, . It is the only species in the genus ''Plectrodera''.
Description
The adult cottonwood borer is a large
longhorn beetle with a black-and-white coloration and black
antennae as long or longer than the body.
["Cottonwood Borer." Texas A&M. http://insects.tamu.edu/fieldguide/bimg177.html Retrieved 2012-02-24.] The white portions are due to microscopic masses of hair.
["Cottonwood Borer." Great Plains Nature Center. http://www.gpnc.org/cwoodborer.htm Retrieved 2012-02-24.] The
larvae
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.
The ...
have legless, cylindrical, creamy-white bodies with a brown-to-black head and grow up to long.
Life cycle
The female cottonwood borer will chew small pits in the base of the tree in which to lay her eggs. The larvae can take up to two years to mature, after which they
pupate in a root below ground level for approximately three weeks. Once
metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some inse ...
has completed, the now-adult chews its way out of the root and digs up to the surface.
Environmental impact
Although larvae can kill young trees by
girdling them, infested mature trees are usually not seriously injured. The larvae can also structurally weaken a young tree, which is then more susceptible to falling over in high winds. Adults feed on leaf stems and the bark of tender
shoots
In botany, a plant shoot consists of any plant stem together with its appendages, leaves and lateral buds, flowering stems, and flower buds. The new growth from seed germination that grows upward is a shoot where leaves will develop. In the spri ...
, occasionally causing
flagging.
References
{{taxonbar, from1=Q15872244, from2=Q5175849
Lamiini
Beetles of North America
Beetles described in 1792