HORTICULTURE

Detailed explanation-1: -Aquatic insects are a very diverse group of insects that include over 100, 000 species adapted to freshwater habitats. They are different from insects because they spend at least part of their life in freshwater. Freshwater habitats are those that do not contain salt or contain very little concentrations of salts.

Detailed explanation-2: -The remaining orders of aquatic insects are holometabolous and have what is known as complete metamorphosis. These insects have four life cycle stages: egg/embryo (Figure 8), larva (Figure 1), pupa (Figure 9), adult (imago; Figure 10).

Detailed explanation-3: -Some insect orders contain only species that are aquatic in some life stages (e.g., mayflies, stoneflies, dragonflies, caddisflies, megalopterans), whereas other orders contain both aquatic and terrestrial species (e.g., beetles, bugs, butterflies, neuropterans, orthopterans, and dipterans).

Detailed explanation-4: -This change in physical appearance is called metamorphosis. The extent of change that the aquatic organism undergoes varies from organism to organism. There are two types of metamorphosis: complete metamorphosis and incomplete metamorphosis.

Detailed explanation-5: -A high diversity of aquatic insect species is of value to humans and animals for a variety of reasons, out of which four are particularly important. They are the role of these insects in (1) food webs, (2) biomonitoring, (3) fishing, and (4) controlling noxious weeds.