Generally speaking, the vast majority of the population considers "bugs" to be the same as insects. However, this is not the case. Bugs refer to "True Bugs" in Suborder Heteroptera. True Bugs can have bodies that are hard or soft. Most times they are flat in appearance if you look at them from a side view. They usually have two sets of wings as an adult and the front set is usually thickened and the hind wings are used to fly. The hind wings overlap to form an "X" on the back, which helps to distinguish them from other insects. They also have a sucking and/or piercing type mouth part.
Some typical "bugs" would be Stink Bug, Boxelder Bug, Leaf-Footed Bug, Shield Bug, Broad-Headed Bug, Minute Pirate Bug, Flat Bug, Water Bug, Stilt Bug, Bed Bug, Burrowing Bug, Unique-Headed Bug, Toad Bug, Big-Eyed Bug, Water Striders, Bordered Plant Bug, Seed Bug, Plant Bug, Damsel Bug, Waterscorpions, Velvety Shore Bug, Ambush Bug, Assassin Bug, Red Bug, Scentless Plant Bug, Shield-Backed Bug, Negro Bug, and Lace Bug. Obviously not all of these occur in Oklahoma but it just shows the wide variety of actual "bugs" that there are. Here is a BugGuide link where you can get more information as well as see more pictures.
Insects are any critter under the Phylum Arthropoda. This includes "bugs". But it also includes any critter that might be commonly referred to as a "bug". See here for more info.
Permalink Reply by Pat on September 19, 2009 at 9:08am
Is there a difference between an insect and a bug?
A: Yes, there is a difference.
* A bug is a certain type of insect. Some examples you might be familiar with are the boxelder bug, milkweed bug, assassin bug, and stink bug.
* True bugs have a stylet (a mouth shaped like a straw) that they use to suck plant juices from plants. The assassin bugs use their stylets to suck blood from other insects.
* The front wings of true bugs are thickened and colored near where they are attached to the insect's body, and are clearer and thinner towards the hind end of the wing. The hind wings are usually clear and tucked underneath the front wings.