Silk worm moth

Pheromones, especially insect pheromones, have become common news stories in the popular press and hence are well known to most people. For instance, most elementary schools in the USA now include coverage of pheromones in general science and biology courses. Concomitant with this widespread coverage and inclusion in elementary school curricula is ongoing basic and applied research, which leads to important practical uses and beneficial applications. Since Butenandt s initial report on the pheromone of the silk worm moth, there have been many reviews of pheromones and recent ones are cited here. This review of the chemistry of insect pheromones will cover the isolation and identification of new pheromones and the synthesis of these compounds as well as other recently reported syntheses of important pheromones. 

Polarimeters for measuring optical rotation are so sensitive that they can measure rotations to 0.001°, an important fact when only small amounts of sample are available. Ecdysone, for example, is an insect hormone that controls molting in the silk- < worm moth. When 7.00 mg ecdysone was dissolved in 1.00 mL chloroform and the solution was placed in a cell with a 2.00 cm pathlength, an observed rotation rf +0.087 was found. Calculate [a]n for ecdysone. 

Juvenile hormone, larval hormone, stalus-quo hormone insect hormone responsible for the control of molting. The first J.h. to be isolated and structurally elucidated was obtained from the abdomens of the male silk worm moth (Hyalophora cecropia) in 200 ig quantities. Homologs of this compound were discovered later, and other J.h. were postulated. Juva-bione (see) and famesol derivatives are among the... 

Bombykol, pheromone of Bombyx mori. the silk worm moth... 

Silk is a fibrous protein produced by several insect species. Commercially, silk is produced from the cocoon stage larvae of the moth caterpillar Bombyx mori, as it has been, in China, for some 4500 years. A single cocoon produces a continuous thread up to 1 km in length, and the protein fibroin contains large amounts of glycine, alanine, tyrosine, proline and serine The peptide chains are arranged in anti-parallel P-sheets which make up the hierarchical structure of the crystalline silk fibres. A number of spiders also produce silk webs, although the fibroin structure is rather different to that from silk worms. 

Silk fibroin is a fibrous protein obtained by the larvae of Bombyx mori, other moth genera such as Antheraea, Cricula, and many other insects. The silk protein obtained from spiders and silk worms produces the toughest and strongest fibres [115]. Silkworms produce silk whose main components are fibroin and sericin amongst which fibroin constitutes the core of silk, and sericin is glue like protein surrounding the core. Fibroin is composed of various... 

In addition to silk moths/worms, silks are produced by many other species of insects and spiders (Kaplan et al., 1992, 1993, 1998). Unlike silk moth-derived silk, spider silks are not widely used in the textile industry because of their limited availability. Spiders naturally produce less silk than a silk worm cocoon (-137 m of fiber can be obtained from the ampullate gland of a spider while one silkworm cocoon yields 600-900 m of fiber) (Lewis, 1996) and, spiders being solitary and predatory in nature, cannot be raised in large numbers. However, it was documented that spider silks are just as suitable for textile production as their insect counterparts (Kaplan et al., 1993). Consequentially, for biomaterial development, silk moths/worms and spiders are the main silk sources. 

S. is a thread spun by the silk moth or silk worm (Bombyx mori). It is composed of two fibroin fibers surrounded by a thin layer of sericin. Fibroin is a ->protein that consists mainly (ft 90%) of the - amino acids glycine, alanine, serine and tyrosine, while sericin consists of 37% serine, and 14.7% each of glycine and aspartic acid. Both contain small portions of other amino acids. S. is highly crystalline (60%). 

There is another silk-producing moth of commercial importance (production volume is 10% of normal s.), called tussah (several Antharaea apecies). It is not cultivated like the mulberry silk worm but is harvested in oak forests. 

Nature has long used reactions such as these to produce interesting solids such as cotton (seed pod), hemp (grass), and silk (cocoons for worms while they develop into moths) as fibers that we can strand into rope or weave into cloth. Chemists discovered in the early twentieth century that cellulose could be hydrolyzed with acetic acid to form cellulose acetate and then repolymerized into Rayon, which has properties similar to cotton. They then searched for manmade monomers with which to tailor properties as replacements for rope and sdk. In the 1930s chemists at DuPont and at ICl found that polyamides and polyesters had properties that could replace each of these. [Linear polyolefins do not seem to form in nature as do condensation polymers. This is probably because the organometaUic catalysts are extremely sensitive to traces of H2O, CO, and other contaminants. This is an example where we can create materials in the laboratory that are not found in nature.]... 

There are all sorts of silk that are found in nature. The stuff that is usually found in textiles comes from silkworms (Bombyx mori). They are not really worms, but the larvae of moths. They emerge from very small eggs with an incredible lust for mulberry leaves, which they consume until they are ready to. pupate and weave a cocoon around themselves. Unlike spiders, which spin silk from their rear end, silkworm silk is actually hardened saliva, which comes out of the mouth. The larva has a small spinneret on its lip, through which the silk emerges. The cocoon is formed from a single strand of silk that... 

Without human intervention, the worm inside the cocoon would develop into a chrysalis and later into a moth. The moth would then burst the cocoon and break the cne lor strand of silk into many ort cnes. But sericulture destroys the worm inside the cocoon by stifiir it with heat. 

Silk, or more precisely, natural silk, is produced by certain worms, caterpillars, and moths. The most important product is the high-quality silk that comes from the mulberry silk moth (Bombyx mori Linne) the larvae use... 

Conventional silk is derived from silkworms that feed largely on mulberry leaves, usually indoors in large trays. This type of silk is called cultivated and is produced on large, industrial mn farms. Cultivation includes the boiling of the cocoon with the worm inside in order to kill the worm before it becomes a moth and emerges from the cocoon. 

Silk fibers are produced by the larvae of specific moth species. There are two major types of silk Tussah silk produced in the wild by Antheraea pernyi and Antheraea mylitta, and Bombyx mori silk, which is produced by cultivated mulberry worms. 

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