Life Cycle of parasite(wasp):-
The life
cycle of parasitic wasp’s depends on other animals such as caterpillars. A
female parasitic wasp lays its eggs inside a caterpillar. When the wasp larvae
hatch, they chew through the caterpillar’s skin from the inside. Then they spin
cocoons around themselves as they become pupae. The caterpillas will carry the
pupae until the adult wasps emerge from them.
Silk worm life cycle
The silk
worm is actually a caterpillar not a worm. Like butterflies larva, silkworms
build cocoons to protect themselves during the pupa stage. Inside the cocoon,
the pupa transforms into an adult moth.
Silk is a
material that silkworms use to make their cocoons. Using the silk excreted from
their salivary glands, each silk worm spin a single thread of silk around
itself over and over again! The silk will eventually harden into a cocoon.
To get silk,
silkworm farmer first boil the cocoons to kill the pupae inside. If the pupae
were allowed to grow and emerge as adult from the cocoons, they would break the
cocoons in the process. Soaking the cocoons in water also softens them and
loosens the threads. The silk threads
can now be remove and spun into silk.
Scientists
are now “engineegring” silkworms in laboratories to produce silk with enhanced
qualities. The silkworms are given some spider proteins, which allows them to
produce stronger, tougher and more elastic silk.
This
improved silk could be used to make medical sutures, artificial ligaments and
even parachutes! Who would have thought the humble silkworm had such a useful
life cycle?
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