Cocoon-spinning larvae

Close observation of sonorensis larvae emerging from their hosts on PI 134417 foliage indicated that they disrupt a large number of glandular trichomes during the cocoon spinning process and contact... 

In a related study, Kauffman and Kennedy (65) demonstrated that the toxicity of PI 134417 and BC2 foliage to sonorensis larvae during cocoon spinning was eliminated when the glandular trichomes were removed. They further demonstrated the acute toxicity of 2-tridecanone and 2-undecanone to sonorensis larvae on treated filter paper disks (2-tridecanone LC50 = 13.0, 95% fiducial limits =... 

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... 

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... 

Fruit contains webbing. Cause Navel orangeworms. These reddish orange, brownheaded larvae bore into cracked fruit and spin their cocoons inside. Control pests by picking off damaged fruit. Clean up dropped fruit. Spray BTK to kill larvae before they enter. 

Once larvae have tunneled into fruit, they are relatively safe from control measures. However, after feeding, they will crawl down the trees to find a place to spin a cocoon. Intercept the migration by tying burlap tree bands around the trees. Check them doily and destroy the larvae. 

Larvae feed for 1 month, spin webs, and pupate within rolled leaves or in cocoons on bark. Adults emerge late June or July and lay overwintering eggs on bark. 

Life Cycle Larvae overwinter in tree trunk burrows in the spring they spin brown silken cocoons at the surface of the burrow or in soil cocoons may be covered with din and gum from the tree first adult moths... 

The life eycle of B. mori is summarized in Fig. 23.1 [21]. In about 50 days it eompletes its life cycle of four different metamorphosing phases egg or embryo, larva, pupa and adult (moth). Of the life cycle, about half is the larval stage, the only stage at which they consume food, mulberry leaves. Pupation occurs at the end of spinning (or cocoon formation) the latter takes... 

Pupal Stage Fully mature larvae spend two to three days spinning a cocoon of fine silky threads and compost fragments. These threads are sometimes detected as slime trails left behind in the sub-... 

But the larva is not interested in the health of the spider at this point. The spider makes a very strong web and stops and sits in the middle, waiting to die. The larva finishes it off by sucking the remaining juices from the spider and drops the carcass to the ground. Later, the wasp larva will spin its cocoon and remain suspended by the web until the adult wasp emerges sometime after dawn. Then, it would find a mate and a spider to attack, and renew the entire cycle (Conniff and Murawski, 2001). 

Other types of spider webs include tangle webs and sheet webs sptm by different species. Many other insects spin silk fibers for cocoons, shelter, egg sacs, egg stalks, and tunnels. For example, tarantulas use silk to spin tunnel-shaped shelters, and spin fibers from their feet as support lines. Caddisfiy larvae spin underwater tubes and nets, and the aquatic midge spins underwater silk tubes. Honeybee larvae spin silk to inCTease the mechanical strength and thermal stability of the beehive. These silks are subject to inaeasing amounts of research, as reviewed in Reference 11. 

C. sonorensis oviposits in second and early third instar zea larvae. The parasitoid larvae kill and emerge from late third and early fourth instar host larvae, crawl onto the foliage, and spin a cocoon in which pupation occurs. 

In industrial production, the silkworm is grown on trays, and the larvae are fed with freshly harvested mulberry tree leaves. Thirty grams of eggs (40000-60000) consume one ton of leaves in the 35 days of their life time. The pupae contained in the cocoons are killed by steam. In the filature (reeling plant), the cocoons are treated with hot water, whereby they are opened to show reelable thread ends. The continuous filaments (up to 3000 m long) are wound onto a hank, which is finally dried. Wastes are used either as spun yams (schappe) or bourette silk, which is made from the wastes of schappe spinning. Dead pupae are used as fish feed. 

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