Crickets

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Crickets belong to the Class Insecta and the Order Orthoptera. They undergo incomplete metamorphosis which means that the young (called nymphs or instars) look similar to adults, usually just smaller and do not have wings. Each time they molt, they develop a little more so that they look more like an adult.

Only the male calls with its familiar chirp. The chirp is made by lifting the wing covers to 45 degrees and rubbing the front area of one wing cover (scraper) against the rough area on the other wing (file). Scientists call this method of making sound (rubbing one body part against another) stridulation. You can make a similar sound by rubbing a file against the edge of a tin can. Each wing cover has both a file and a scraper so they can alternate rubbing one side against another. This is thought to decrease the wear on the file so the cricket can continue to chirp for a long time.
  Underneath the wing covers are modified wings. They are so modified that the cricket cannot fly. Instead it scrambles and hops about in long grass. The bristles on their legs help them to grip the long grass to scurry away from predators.

Crickets are eaten by small owls, snakes, mice, shrews, frogs, raccoons, opossums and many other creatures. They are an important creature in the food web.

Scientists used to believe that chirp we hear was their way of communicating with each other. Now they know that male crickets are able to make a high pitched sound which humans cannot hear. It is these sounds which they use to talk only to other male crickets. The chirp we hear is made by the friction of rubbing their wing covers together. The chirp is most noticeable during warm summer evenings and continue into the autumn. When the first frost occurs, the chirping stops because the crickets are too cold to move.

You can calculate the air temperature (in degrees F) where a house cricket sits by using the following equation: Temperature=50+(Number of chirps per minute-40)/4
(temperature equals fifty plus number of calls in one minute minus 40 divided by four)

Male crickets make three kinds of calls: calling note to defend their territory, an aggressive chirp to tell other male intruders to move on, and a quieter call which announces their presence to deaf females. If another male ignores the warning chirp, the cricket who has been invaded will run and attack the intruder until either he runs away or one of them is injured and sometimes killed.

Male crickets ears look like a single white dot near the bend of each front leg near the elbow. This is why they are thought to listen with their elbows! Female crickets are, in fact, deaf, and some types rely on the smell given off by the male as he raises his wing covers to make his call.

Sexes are easy to tell apart if you know what to look for. The wing covering on male crickets are larger and more vein-patterned than females. Female crickets have long tube called an ovipositor (or egg depositor) that sticks out like a tail. These are used to lay their eggs deep under soils and leaves to protect them from frost. Males do not have the ovipositor.

The Black Field Cricket is nocturnal and hides under logs and in burrows during the day. It is shiny black in color with antennae longer than its body. Interestingly, it will chose burrows with south-facing entrance holes so the sun can flood in and warm itself. Males call from their own burrows.

They are scavengers and eat fresh clover, grass, fruits and dead insects (including other crickets) and bits of meat. If you watch closely, you can see their jaws moving sideways as they chew, not up and down like humans do.

Crickets make great temporary classroom pets if you make sure they have an aquarium with a tight lid, some moist (but not wet) soil, several hiding places and are fed with fresh fruits and a little bone meal or calcium to prevent canabalism. Water can be provided on a small sponge. Try the above temperature calculation to see if it works for the species of cricket you have caught. Each type of cricket varies the speed of chirps depending on the air temperature. They will also respond to different musical instruments and different pitches of sound.

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