Crickets are surprising creatures that many of us know very little about. Now is the perfect time of year to observe them and discover their astonishing secrets, as the May sun warms our middays and tempers our evenings.
The most common species found in our countryside is the field cricket (Gryllus campestris), a mid-sized insect (between 2 to 3 centimetres long), shiny black in colour, with a pair of frontal antennae protruding from its oversized head.
If we look closely at its dark-coloured back, we'll discover a distinctive gold band at the base of the cricket's wings. These cover the length of the abdomen, which culminates in two spectacular, pointed appendages, but no need to worry: crickets don't sting.
Habitual denizens of the vineyards and surrounding fields, they are mainly crepuscular and nocturnal, but they do take advantage of sunny May afternoons to emerge from the deep holes of their burrows to bask in the sun and begin emitting their signature call. The sound contains one of nature's most surprising secrets
Vineyard in Tremp, a Familia Torres property
The song of the cricket, a high-pitched cri-cri-cri that can be heard across great distances, is known among scientists as stridulation. The insect produces this rhythmic, chirping sound by rubbing its elytra (what entomologists call the forewings of Coleoptera) together.
The variations in the field cricket's song denote different purposes, either to mark territory or begin the courtship and mating period. In other words, the song has lyrics of sorts, an encrypted message that can only be deciphered by fellow crickets, which transmits information related to the defence of their territory or the mating ritual.
But the stridulation of field crickets does more than allow them to communicate with each other – they also convey information to us, a coded message that we might find very useful.
Country people maintain a tradition of listening closely to the cricket's song to calculate the air temperature and predict the following day's weather. And this isn't just rural lore – it has a scientific basis.
It turns out that the insect's organism – much like that of reptiles, for example – interacts directly with the surrounding temperature, accelerating or slowing down its metabolic rhythm. When it's cold, the song is slower and comes at longer intervals, whereas in hot weather, it is faster and more vigorous.
To calculate the air temperature based on the cricket's song, we must first select an individual subject. Then we'll start counting the number of notes it produces during the span of a minute (it's best to jot the notes down as tally marks because there are a lot of them, so bring a pencil and paper). Avoid disturbing the insect and don't make your presence known as this will silence the cricket instantly.
At the end, add up all of the notes, divide the total by five, and subtract nine. The result will reflect the air temperature in degrees Celsius. If you decide to do this exercise, compare the result to a temperature reading – the numbers add up, you'll see.
Here's another curious detail about these meadowland musicians. Play Vivaldi's The Four Seasons while listening to the crickets sing. The best way to do this is by wearing headphones with the music turned down low enough so that you can still hear the insects. Surprising, isn't it? It seems like they're following the same score, right? Nature is full of wonders, as is the genius of the great Venetian composer who so often turned to it for inspiration.