Caterpillars cocoons

The larvae that hatch from Cotesia eggs remain inside their caterpillar host, exploiting it as a secure haven from the outer world and a convenient food supply. They feed on the caterpillar from within until they are mature and ready to pupate. Then they emerge from its body and immediately begin spinning small white cocoons, which they attach by one end to the caterpillar s back. It is not uncommon for a tobacco hornworm, still alive, to be festooned with fifty or more Cotesia cocoons, each resembling a diminutive grain of rice fastened to the caterpillar. Each cocoon contains... 

The larvae are green, IVz- m (4-cm) caterpillars with two white lines down their backs, one along each side. They feed for 2 to 4 weeks, then pupate 10 days in cocoons attached to stems or leaves. There are three to four generations per year. 

Symptoms Tiny yellow-green caterpillars tunnel into the leaves, and then through into the stems and growing point of the plant Small dark brown cocoons may be seen on the plant and secondary rots may develop. 

What to do Where this pest is a regular problem, grow leeks under fine mesh netting to keep the moths out Once plants are infested, there is no control other than hand-picking of caterpillars and cocoons from the leaves, or removing the whole plant Clear up all plant debris at harvest Dig over the leek beds. Encourage predators... 

What to do Flandpick caterpillars from plants, unless they are covered with small, white, rocklike projections, which are actually the cocoons of parasitic wasps. Spray with Bacillus thuringiensis var. kurstaki (B.T.K.) while caterpillars are still small. 

As we shall see, cyclization reactions of this general type seem to be important in terpene biosynthesis. The 6,7-trans-farnesol has been shown to have hormone action in some insects. It acts to regulate the changes from caterpillar to cocoon to moth. 

Insects also produce polymers. For example, silk is made by a caterpillar called a silkworm. One silkworms cocoon can contain as much as 900 to 3,000 feet (300 to 900 m) of silk thread. An insect called the Laccifer lacca—or just Lac, for short—lives on trees in India and Southeast Asia. The insects drink the sap from the trees they are living on and produce a polymer that is used to make lacquer and shellac. People use these varnishes to coat and protect ships, houses, wood floors, furniture, and other objects made of wood. 

Tent caterpillars on a cocoon, Glacier North Park, Montana. Insecticides are used to eradicate populations of such species where they are not desirable. 

The silk from the cocoon of the mulberry silk spinner caterpillar [Bombyx mori) has been the most important source of natural silk for textiles for more than 5000 years. The cocoons consist of about 80% silk fiber and 20% glue. After immersion in hot water to soften the glue, the cocoons are treated with mechanical brushes that unwind the fibers. 

The process of raising the caterpillars, harvesting the cocoons, and obtaining the silk fibers requires much hand labog meaning that items made of silk are quite expensive relative to those made of other... 

Silk fabric and thread are derived from the cocoons that some insects make as part of their metamorphosis from caterpillar to butterfly or moth. Most commercial silk is created by Bombyx mori, a small moth that was originally native to Asia. These animals no longer live in the wild, and in cultured populations they have lost their ability to fly. 

When the internal clock inside a caterpillar (i.e. hormones) tells it that the time is right, it creates a pupa or cocoon made of silk filaments secreted by two glands on its head. The tiny threads are combined, as they form, with a gummy substance that glues them together. 

Tussah or wild silk is obtained from caterpillars that are not cultivated, living naturally on mulberry, cherry, or oak trees. The cocoons are gathered by and processed by hand, resulting in an uneven and irregular product. Tussah is tan or brownish, depending on where the caterpillar had been living and what it had been eating. Tussah is often mixed with other fibers to produce hybrid fabrics. 

At the end of June the caterpillars spin a cocoon under loose bark, where they overwinter. 

DEVELOPMENT OF THE SUMMER FRUIT TORTRIX. The Summer fruit tortrix moths overwinter as young larvae in a cocoon on the tree, usually under the remains of dead leaves. Before flowering the first caterpillars move from their winter hiding-places to the flower huds or rosette leaves and weh several leaves together in order to feed and grow there. They may also feed on the young fruit. The places where caterpillars have fed can later he seen on the fruit as scars of varying depth. 

About 500-1000 apples should be checked. The damage threshold is 2 % of apples infested. It is very dangerous if this threshold is exceeded, as the caterpillars usually live in old cocoons, where they are difficult to control with plant protection products. 

When the caterpillars are fully grown they leave the tree and pupate in the soil in a cocoon. 

NATURE OF DAMAGE. On the leaves and fruit there is damage due to feeding, with a small cocoon. A spoon-like cavity may be eaten out of the fruit. Older caterpillars skeletonize the leaves and make holes in them. 

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. 

Growing shoots wilt and die. Cause Oriental fruit moth larvae. Slit the stem below the wilted portion and look for a pinkish white, A" caterpillar—the larva of an oriental fruit moth. Larvae tunnel into shoots and remain for 2 weeks before leaving to pupate for 10 days in cocoons suspended in trees. Larvae from later generations bore into and ruin fruit. Use pheromone traps to monitor and control the pests. Mating disruption pheromones, such as Isomate-M, are also effective. Replace them every 90 days throughout the growing season. For heavy infestations, spray superior oil to smother eggs and larvae. 

Leaves with large holes. Causes Horn-worms other caterpillars. Hornworms are y -4Vi" caterpillars with white diagonal stripes. The tobacco hornworm has a red horn projecting from the rear, while the tomato horn-worm fias a black horn. Handpick or spray plants with BTK to control them. Do not spray eaterpillars that are covered with small white cocoons these cases eontain the larvae of parasitic wasps that are natural hornworm predators. 

Description Adults males are black, clear-winged moths (1" wingspan) females are wingless. Larvae dark brown, V4 -l" caterpillars with white or yellow heads feed inside cocoons. Eggs light tan eggs laid inside bags. Found east of Rocky Mountains. 

Control Prune infested branches and burn them, or remove tents filled with caterpillars from branches by winding them onto a broomstick with nails projecting from it in winter, remove egg masses from bare branches attract native parasitic flies and wasps by growing small-flowered herbs, such as catnip, and wildflowers, such as Queen Anne s lace. Do not destroy wandering caterpillars with white eggs or cocoons attached to their backs they are hosts for native parasites. Spray BTK weekly while larvae are small try releases of spined soldier bugs. 

Along with cotton and wool, silk had long been one of the most useful fibers known to man. The material comes from the secretion of the mulberry leaf-feeding silkworm, Bombyx mori, a family of Lepidoptera that includes large moths and butterflies. The mature caterpillar produces a clear, viscous fluid called fibroin, which, in combination with another fluid called sericin, forms the solid filaments of silk that make up the cocoon. 

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