Red-brown rice flour beetle
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Red-brown rice flour beetle ( Tribolium castaneum ) |
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| Tribolium castaneum | ||||||||||||
| ( Autumn , 1797) |
The red-brown rice flour beetle ( Tribolium castaneum ) is a beetle from the family of the black beetle (Tenebrionidae).
features
The beetles are light red to brown in color and reach a body length of three to four millimeters. The body is elongated and narrow, the head and pronotum are slightly darker than the wing covers . The antennae end in a three-part club. The wing covers are provided with longitudinal ridges, between which there is a series of fine points.
The eggs are covered with a sticky secretion so that they adhere well to the brood substrate and are difficult to detect.
The larvae are caterpillar-like , yellowish in color and reach a length of up to eight millimeters. The head capsule is dark in color. The larval body has three pairs of legs and two pushers on the 9th abdominal segment .
The pupae are yellowish to brownish in color and three to four millimeters long. They lie freely in the brood substrate.
Similar species
A similar species, the American flour beetle ( Tribolium confusum ), which originally comes from Africa , looks confusingly similar to Tribolium castaneum . Today it can be found in cooler areas around the world (for example, northern states of the USA). A distinguishing feature, however, is the clearly separated three-part end lobe of the antennae in Tribolium castaneum . In Tribolium confusum the limbs gradually increase in size towards the apex without forming a club. Further distinguishing features: With Tribolium confusum above the eyes a detached, protruding edge, Pronotum with Tribolium castaneum broadest in the middle, with Tribolium confusum in the front third.
Occurrence
Tribolium castaneum was originally native to the Indo-Australian fauna, where it lives under tree bark. The species can now be found practically everywhere in temperate latitudes and in centrally heated rooms.
Way of life
The beetles can live up to three years, during which time a female lays several eggs a day, up to 1,000 in total. The ideal development conditions are between 32 and 37 ° C and 70 percent humidity, the cycle from egg to imago is completed within 27 to 35 days.
pest
Tribolium castaneum is one of the stored food pests, under optimal living conditions it can quickly lead to high population densities and severe damage to stored food. Grains and their products as well as peas, beans, seeds, raisins, cocoa, sunflower seeds, peanuts, etc. are attacked . The species often comes to Central Europe via food imports and is mainly to be found in large mills, from where the beetles are then sold to retailers. In order to control the beetles, it is recommended to destroy the infected food. Newly purchased products can be stored in the freezer for 24 hours, within this period of time all stages of development are killed. Various contact insecticides and non-toxic silica -based products are also available on the market. The latter destroy the cuticle , which leads to the beetles drying out.
Model system in science
Tribolium castaneum is developing into an important genetic model system. Since March 24, 2008, it is the first beetle whose genome has been sequenced; its genome comprises 16,000 genes (for comparison: humans have around 32,000 genes), several hundred of which were not found in Drosophila . The function of genes in the flour beetle can be switched off very efficiently by systemic RNA interference (RNAi). Finally, the mis-expression of genes is possible and further transgenic methods are established. Science hopes that the meal beetle model system will provide information on embryonic development , metamorphosis, the evolution of body diversity and the control of pests.
He also plays an important role as an example of the biological application of chaos theory . In particular, its cannibalism leads to a non-linear population dynamics with diverse properties, which are the subject of numerous studies.
Individual evidence
- ↑ United States Department of Agriculture (editor): Stored grain insects. Agriculture Handbook No. 500th revised edition 1986 PDF ( Memento of the original dated February 16, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ^ Tribolium Genome Sequencing Consortium, Richards S, et al. : The genome of the model beetle and pest Tribolium castaneum. Nature . 2008 Apr 24; 452 (7190): 949-55. Epub 2008 Mar 23. PMID 18362917
- ↑ http://math.arizona.edu/~cushing/Science1997b.pdf
