Derris
Encyclopedia
Derris is a climbing leguminous plant of Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

 and the southwest Pacific islands, including New Guinea
New Guinea
New Guinea is the world's second largest island, after Greenland, covering a land area of 786,000 km2. Located in the southwest Pacific Ocean, it lies geographically to the east of the Malay Archipelago, with which it is sometimes included as part of a greater Indo-Australian Archipelago...

. Its roots contain rotenone
Rotenone
Rotenone is an odorless chemical that is used as a broad-spectrum insecticide, piscicide, and pesticide. It occurs naturally in the roots and stems of several plants such as the jicama vine plant...

, a strong insecticide and fish poison.
Also known as Derris powder, it was formerly used as an organic
Organic farming
Organic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...

 insecticide
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...

 used to control pests on crops such as peas. However, due to studies revealing its extreme toxicity, as well as due to the concentration level of rotenone
Rotenone
Rotenone is an odorless chemical that is used as a broad-spectrum insecticide, piscicide, and pesticide. It occurs naturally in the roots and stems of several plants such as the jicama vine plant...

 to which the powder is often refined, experts in ecological and organic growing no longer consider it ecologically sound. Rotenone is still sold in the U.S., however.

Derris root, when crushed, releases rotenone. Some New Guinea natives practice a form of fishing in which they crush the roots and throw them into the water. The stunned or killed fish float to the surface where they can be easily reached. In Indonesia these roots are called tuba.

Despite its toxicity, Derris is used as a food plant by the larva
Larva
A larva 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...

e of numerous Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 species including Batrachedra amydraula
Batrachedra
Batrachedra is the largest genus in the moth family Batrachedridae.It includes the following species:*Batrachedra acrodeta*Batrachedra agaura*Batrachedra albanica*Batrachedra albicapitella*Batrachedra albistrigella...

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK