Butterflies come to pretty flowers.
A Korean proverb
Although many insects are considered to be pests (= insects that damage plants or supplies of food), they are also very important for many reasons. Insects are crucial components of many ecosystems, where they perform numerous functions – from pollination (placing pollen from one flower on another flower in order to help it to produce seed) to pest control. Read on to expand your insect vocabulary…
COMMON INSECTS*
*An insect has 6 legs, but some creatures from the list below have more. For example, centipedes, and scorpions. Technically, centipedes are not insects, but they are closely related invertebrates /ɪnˈvəːtɪbrəts/ – animals lacking a backbone. As for scorpions, although they are not insects, they are distant cousins of spiders.
- caterpillar /ˈkætə(r)ˌpɪlə(r)/
- cocoon /kəˈkuːn/
- butterfly
- dragonfly (a – wing)
- cricket
- grasshopper
- (praying) mantis /ˈmæntɪs/
- scorpion (a – sting)
- cockroach /ˈkɒkrəʊtʃ/ (= roach – American English)
- beetle
- termite /ˈtɜː(r)maɪt/ (= white ant – British English)
- ant
- mosquito
- ladybug (American English) / ladybird (British English)
- web
- spider
- firefly
- fly
- bee
- wasp /wɒsp/
- moth
- centipede /ˈsentɪpiːd/
WHAT’S THE INSECT?
Choose the right word from the list above to complete the definitions (the answer key is at the bottom of the page):
- A small insect that eats wood and can damage buildings is a … .
- An insect that produces a flashing light when it flies at night is a … .
- A small round beetle that is red with black spots is a … .
- An insect like a butterfly which usually flies about at night is a … .
- A long, thin creature with a lot of legs is a …
- A large, green insect that holds its front legs in a way that makes it look as if it is praying is a … .
- A small, long animal with many legs that feeds on the leaves of plants, and develops into a butterfly or moth is a … .

BEETLE vs. BUG
Note that a bug (informal) is an insect or similar small creature, and a beetle is an insect with a hard covering to its body. So, all beetles are bugs, but not all bugs are beetles. Examples of beetles: ladybugs, cockroaches, scarabs, etc. Examples of bugs that are not beetles: caterpillars, mosquitos, moths, etc.
The word bug has other meanings: 1) (informal) an illness that is usually not serious and is caused by bacteria or a virus: Jamie has picked up a bug (= Jamie has caught an infectious illness). 2) a mistake or problem in a computer program: A bug caused the company’s computer system to crash. 3) a tiny hidden microphone which transmits what people are saying: There was a bug on the phone. 4) a sudden strong enthusiasm for doing something: She’s been bitten by the cooking bug.
Bug is also a verb: 1) It really bugs (= annoys) me when people smoke in restaurants. 2) She keeps bugging (= asking in an annoying way) me to paint the kitchen. 3) He was convinced that his office was bugged (= there was a hidden microphone in the office).
INSECT IDIOMS
- To have/get/feel butterflies (in your stomach) – to be very nervous or excited about something: Do you get butterflies when you have to talk to lots of people?
- To have ants in one’s pants (British English) – to be restless or impatient: My children have ants in their pants because tomorrow is Christmas and they are excited about their presents.
- (Sb.) wouldn’t harm/hurt a fly – used for saying that someone is very gentle and would not do anything to hurt or upset anyone: Terry may look tough, but he wouldn’t hurt a fly.
- To be a fly on the wall – to be able to watch what people are doing without them noticing you: I’d love to be a fly on the wall when they find out.
- A fly in the ointment – a problem that spoils something or makes it difficult: The only fly in the ointment is that we can’t use my house for the party.
- To have a bee in your bonnet /ˈbɒnɪt/ – to think something is very important and think or talk a lot about it, in a way that other people may find annoying: She never stops talking about dieting – she’s got a real bee in her bonnet about it. A bonnet is a hat that ties under your chin.
- A busy bee – someone who is always busy doing things: She’s such a busy bee.
- To stir up a hornet’s nest – to cause a situation that makes people very angry or upset: There is no need to stir up a hornet’s nest. A hornet is a type of large wasp.

Answer key: 1. termite 2. firefly 3. ladybug 4. moth 5. centipede 6. mantis 7. caterpillar
Materials used: “The New Oxford Picture Dictionary” by E.C. Parnwell