Hobbies And Interests
Reproduction
Only adult insects are capable of reproducing. Adult females will mate on land and return to the water to lay down eggs, but their reproductive cycles and strategies can vary. Some insects will deposit eggs on objects under water, while others will place them on rocks or trees above the water. Eggs generally hatch within a few days or weeks, although eggs of certain species won't hatch for many months. It is typical for aquatic insects to reproduce once per year, but some species do reproduce more often.
Complete Metamorphosis
Complete metamorphosis is sometimes referred to as complex metamorphosis. It is a life cycle that contains four stages: egg, larva, pupa and adult. The egg is the embryonic stage of all insect life. Once in the larva stage, insects take on a wormlike shape. This is the "feeding" stage of the insect life cycle where most growth occurs. Caterpillars and maggots are examples of the larval stage in insects. Larvae molt (shed) their skin several times as they grow. Then, during the "nonfeeding" pupation stage, larvae are encased in cocoons. They will ultimately transform into adult insects with wings. This change takes anywhere from days to months, after which the adult breaks out of the cocoon. None of the insects in the juvenile life cycle stages during complete metamorphosis resemble the adult stages.
Incomplete Metamorphosis
Incomplete or simple metamorphosis has three stages: egg, nymph and adult. A female insect lays eggs which are often covered by a case. It protects the eggs and holds them together. The eggs hatch into nymphs that look like small adults, but generally without wings. Insect nymphs eat and molt numerous times. The phases between insect molts are known as instars. They stop molting once they reach their adult reproductive stage. Dragonflies are an example of an aquatic insect that undergoes incomplete metamorphosis.
Adult Growth
Insects shed their protective external skeleton (known as an exoskeleton) periodically to get bigger. They grow a new skin underneath and then they ingest water to make themselves larger until their thorax splits, allowing the old exoskeleton to break off. They will continue to ingest water to increase their size; this smooths out any wrinkles in their new exoskeleton. This is a dangerous time for the insects; they have decreased mobility and their new skin is initially soft and can be damaged easily. Depending upon the species, their adult lifespan can range from a few minutes to three years.