Right along with cooler temperatures, shorter day length and changing foliage color, the sound of crickets chirping is a sure indicator that fall has arrived. Common questions this time of year includes: Are crickets harmful? Do they eat plants? What if they get inside our house? Here are a few facts regarding these musical insects, which are in the grasshopper family.
Although crickets normally live outdoors, feeding on garden debris, they may occasionally invade homes seeking moisture. They can become a pest by their presence. Their monotonous chirping can be especially annoying at night when you are trying to sleep. In addition, they can feed on a wide variety of fabrics, foods and paper products. Cotton, linen, wool, rayon, nylon, silk and furs are susceptible, along with soiled fabrics, wallpaperpaste, glue from book bindings, fruit, vegetables, meat and even other crickets. An occasional cricket or two in the home usually presents no serious problem. However, large populations may congregate around lights at night making places unattractive.
The easiest way to prevent crickets from getting inside the home is to make sure all windows and doors are tight fitting, with proper screening in place. Exclusion is an important factor as well as light discipline. Avoid bright mercury vapor lights in entryways and along structure perimeters since crickets will be attracted from far distances. Convert to sodium vapor yellow lights (less attractive to insects) instead of white, neon or mercury vapor lights. Clean up piles of leaves, bricks or lumber next to the foundation. Store firewood away from the foundation. Ivy and other groundcovers should be trimmed at least 18 inches away from the wall. Crickets often congregate under garbage cans in great numbers. Elevating the cans on bricks or placing them on a cement pad will help eliminate hiding areas.
A large vein, called the stridulatory organ, which runs along the bottom of each wing, emits the chirping sound made by crickets. This vein is covered with teeth, much like a comb. The familiar chirping sound is created when the cricket runs the top of one wing along the teeth at the bottom of the other wing. As he does this (only male crickets chirp) the cricket also holds the wings up and open so that the wing membranes can act as acoustical sails. It is a myth that crickets chirp by rubbing their legs together.
Smoke detectors or alarms occasionally give off cricket “chirp-like” sounds. This mechanical chirping is a signal repeated at regular intervals, both during the day and night, warning that the battery is weak and needs to be replaced. After learning the source, more than one homeowner has been relieved and “embarrassed” for blaming crickets for the noise.
Entomologists have identified four separate cricket songs. The loudest is used to attract females and repel other males. The courting song, which is much quieter, is used when a female cricket is near. An aggressive song is used when the antennae detect the presence of another male cricket and a copulatory song is produced for a brief period after mating.
On a final note, you can actually get a rough idea of the temperature outside by counting the frequency of chirps. Simply count the number of chirps in fifteen seconds and then add 37. The number you get will be an approximation of the temperature in degrees Fahrenheit.