Summary: Insect wings are one of the most interesting parts of insects because they have such variety and intricacy. Insect wings come in various numbers, patterns, and sizes while exhibiting a complex structure and amazing engineering.
Insects can have one or two sets of wings or none at all. Not all insects have two pairs of wings, although most that have wings do. Some, such as flies, have only one set of wings. Bees, as well as some other insects, use both pairs of wings synchronously, just as if they only had one set of wings.
There are some insects that have no wings at all. These unfortunate creatures are stuck crawling along the ground where they can be squished by humans and elephants. However, one could argue that it is easier for the wingless to hide from predators because they are not flying aimlessly through the open air where anyone can see them and swoop down for the kill.
The colors and patterns found on insect wings are full of variety. Insects, themselves, have a variety of colors so their wing colors are even more variegated. Many seem to have black wings, but if you look closely enough you will see glints of other colors. This iridescence adds to their beauty. It is ironic that the common (and often pesky) housefly could be considered beautiful.
Other insects such as butterflies and moths have exquisitely beautiful wings. The bright colored scales form wing patterns that are meant to frighten off attackers. A familiar example of coloring is the Monarch butterfly. Monarchs are poisonous and their coloring warns predators are to stay away. The Viceroy butterfly, however, is not toxic to predators, but it is still protected from being eaten because its color and design is very similar to that of the Monarch. This copying of colors is called mimicry. Many harmless butterflies have similar patterns to poisonous ones, providing protection for the non-poisonous butterfly.
The size of an insect's wings makes a huge difference in its flight abilities. Because butterflies and moths have very large wing spans and very small bodies, they can often be easily overpowered in stronger winds. Proportionately, smaller winged insects have more control enabling them to perform better in rough conditions.
The structure of insect wings is also very complex. Wings are made up of an extremely thin membrane with veins running throughout. There is no muscle in the wing itself, only in the base, and yet they are able to support the weight of the insect, allowing the insect to easily perform many moves that an experienced fighter pilot would find difficult. Insects in the beetle family have wings that lift from under their back when they take flight. This convenient storage place often makes them seem to be wingless.
Insect wings are remarkable displays of aerodynamics that mankind has yet to copy. Engineers have not been able to create a flying object with wings that flap like insects, although many of the early flight attempts began like this. If you've ever seen primitive video of these attempts, it's quite humorous. Insects flap their wings incessantly and at very high rates in order to fly. They can flap their wings hundreds and sometimes even thousands of times per second, creating the buzzing noise that makes us swat the air and run for cover.