A myriad of people have heard that insects actually sing. But when speaking of biology, what is a singing insect? In biology, a ‘song’ is referred to as a sound which is made by a specific animal during their breeding season. Therefore it is the noise they make in order to attract a mate. Other times the song is used to defend the animal’s territory. Within the animal kingdom it is the males which do the singing. The females rarely sing and when they do, it is usually in a subtle tone in comparison to the males. Surely you have heard the baritone of a frog. When winter ends the male frogs serenade the females prior to mating. Listening to a host of excited bullfrogs can be an experience indeed. It is certainly noisy!
Have you ever listened to the sweet trill of a male canary? Hauntingly beautiful isn't it? The whistling is the bird’s way of staking out his territory during the spring and the early summer. This is melodic music (pardon the pun ) to the ears. And just as these particular animals mentioned above sing, so do insects. Once the frogs and birds settle down during the summer, one becomes very aware of the chorus of insects. Now you will be serenaded by the cacophonous assortment of trills, buzzes, scrapes, shuffles and so forth. These are all the sounds of the cicadas, crickets and katydids serenading the females of their specific breed. They will continue choir practice until the weather dampens their enthusiasm and brings heavy frosts.
Perchance you have wondered how the insects make the various sounds. Katydids and crickets produce their songs by rubbing their wings together. But it is only the fore-wings which they actually use.They have a structure on the undercarriage of one wing which is very similar to a file. On the top of the other wing is a sharp edge/scraper. When these are rubbed together it produces a song like sound. This method of producing sound is deemed ‘stridulation.’ When the file is drawn across the sharp edge/scraper, the thin membranes on the wings then vibrate rapidly. This produces the song. If you are fortunate enough to observe a tree cricket, you will note that they hold their wings vertically when they sing (straight up.) The katydids differ in the fact that they elevate the wings just a little bit when they beginning singing.
Short-horned grasshoppers ( locusts) are a delight to listen to. They do not rub their wings together. They rub their legs together against their wings. They have short peg like structures on the inside of the hind legs. These are rubbed against the stiff outer edges of the rear ( hind ) wings. To listen to their song, one needs very good hearing indeed. The band-winged locust creates rattling/clicking sounds as they fly in the air. This is usually accompanied by a flashing of their wings. You may be fortunate enough to witness this as you trek through a picturesque rainforest. To watch this is a phenomenon indeed. This type of song making is known as ‘wing snapping’ or ‘crepitating.’ The sound is basically produced by the wing membranes becoming taut. Watch a courtship flight and you will be witness to this. But at times this phenomenon can be the result of the locust being startled.
Have you ever wondered how cicadas create their song? Their incredibly noisy music is created in a very different manner. The cicadas have sound producing organs which are called ‘tymbals’ which are located at the base of the abdomen. Inside the tymbals are flexible ribs which are quite stiff. These support a thick membrane. The muscles which are attached to these ribs pull the tymbals inwards. When this occurs, the sound is somewhat like a loud pop. As the tension is released the tymbals pop once again. When the tymbal muscles contract and retract, the sound created is somewhat like a buzzing. The reason this is so loud is due to the fact that the abdomen has a hollow area similar to the inside of a drum. Therefore the sound is amplified.
Now you are well informed about the songs of the insect world. Next time you walk through the forest, stop and listen to Mother Nature’s finest orchestra.