What is a cricket?
A cricket is an insect. Insects have three main body parts, six legs and antennae. A cricket has two pair of legs that it can walk with and the last pair are longer for jumping. Unlike it's cousin the grasshopper, it tends to be dark brown or black. Crickets also tend to be more active at night although may be seen during the day. Some males like to call from burrows which they defend, while other males and females move from one place to another.
How do you distinguish between males and females?
One way to identify the sex of a cricket is to look for a long structure coming out of the tail. This structure is the ovipositor that is used by the female to push eggs into the ground while laying. Another way is to look at the wings, female wings are smooth with the wing veins running straight down the back. A look at male wings reveals a wrinkled effect. There are ridges on the wings that form a scraper and a file. When the wings are rubbed together at high speeds a species specific song is produced.
What kind of life cycle?
The cricket has incomplete metamorphosis. This means that when the tiny nymph (baby cricket) hatches from the egg, it already looks like a cricket. It does not have wings yet, but it's body structure is very similar to the adult only smaller.
How do you determine whether or not a cricket is an adult cricket?
The best way is to look for wings, Only adult crickets have fully grown out wings. Male and female behavior is also different. Only females can be seen pushing their ovipositor into the soil. Only males sing and fight. Males also defend territory around their burrow. A male calls for two reasons. One is to call in females who are flying around searching for males. Another reason males call is to signal other males to stay away from his territory.
How can a fly parasitize a cricket?
There is danger in the air on those warm summer nights for the male who is singing. There is a fly that can hear him calling. This fly is a female and is full of larvae ready to drop onto the calling male. The fly locates it's host by listening for a calling male. The fly then quietly deposits the larvae on or near the calling male. The tiny larvae immediately dig through the exoskeleton of the cricket. The larvae live and grow inside the body of the male until it is ready to pupate. At this point it then chews a hole to get out and then pupates on the ground.
Why study cricket behavior?
The cricket is an ideal animal to study for many reasons. They are small and are easily raised. They demonstrate many behaviors that more complex animals also exhibit. Males call females from long distances in the night. They also have a quiet courtship song when they have found an interested female. The males also have an aggressive song they challenge other males with during a fight. Another behavior some males exhibit is quietly sitting close to a singing male and intercepting any female attracted to the calling male. This is called satellite behavior. When a male takes advantage of finding females without the risk of being attacked by the parasitic fly. A calling male attracts many females but has a short life span due to parasites. The non-calling male does not attract many females at one time but then lives longer and continues to mate. This is seen a the maintenance of two equally successful strategies for mating. This also a classic example of a parasite influence an animal's sexual behavior. Some of these behaviors are can be easily seen in the classroom.
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