The world is filled with a symphony of unseen noise, and a significant portion of that orchestra is composed of insects. From the steady drone on a hot summer day to the rhythmic chirping that defines a quiet evening, these sounds are a constant backdrop to our lives. An insect sound identifier, whether a person’s learned skill or a technological tool, uses these distinct auditory signatures to distinguish one species from another, turning a confusing chorus into an identifiable collection of individual performers.
Common Sound-Producing Insects
Among the most recognizable insect vocalists are crickets, whose high-pitched chirps are a hallmark of late summer and autumn evenings. Their sounds are pure-toned and can be delivered as short, separated chirps or as a continuous trill. Similarly, katydids produce a range of sounds, but they are harsher and more varied than those of crickets, sometimes described as a “tsip” or a raspy rattle. Their calls are a familiar component of the nighttime soundscape.
During the hottest days of summer, the loud, droning buzz of cicadas dominates the environment. Their song is a near-continuous call that can build in intensity and then wind down. Unlike the sharper sounds of crickets, the cicada’s noise is a powerful, vibrating hum that can be heard from high in the treetops. Grasshoppers also contribute to the daytime chorus, producing buzzing or clicking sounds by rubbing their hind legs against their wings. These sounds are short and rhythmic.
Tools for Insect Sound Identification
Smartphone applications have emerged as a primary tool, using a phone’s microphone to record and analyze insect calls. Apps like Seek by iNaturalist allow users to point their phone’s camera at an organism to identify it, and while primarily visual, it draws from a massive database that includes sound associations. For more sound-specific identification, apps like Cicada Safari are designed to map and identify different broods of cicadas based on their distinct mating calls.
These applications work by comparing a recorded sound to a library of known insect calls, using an algorithm to analyze the sound’s frequency, pattern, and timing. This analysis matches the sound to the closest corresponding species in its database. This process is similar to how sound spectrograms have been used by scientists for detailed analysis of an insect’s unique acoustic signature.
Online resources also offer extensive sound libraries for a more hands-on approach. University extension websites and natural history museums often host collections of insect recordings. These databases allow users to manually listen to the calls of common insects in their region and compare them to the sounds they are hearing.
The Science of Insect Communication
The sounds insects produce are not random noises; they are a sophisticated form of communication. The most widespread method for sound production is stridulation, where an insect rubs one body part against another. In crickets and grasshoppers, this involves rubbing a scraper on one wing against a file-like structure on the other wing or leg. This action produces their characteristic chirps and buzzes.
Cicadas employ a different mechanism. Male cicadas have specialized structures called tymbals on the sides of their abdomen. These are ribbed membranes that they rapidly vibrate by contracting and relaxing muscles, producing their loud calls. The cicada’s hollow abdomen acts as a resonance chamber, amplifying the sound to levels that can exceed 100 decibels.
The primary purpose of these sounds is reproduction. Males produce specific calls to attract females of the same species, and females can assess the fitness of a potential mate based on the quality of his song. Sounds are also used to warn away predators or signal alarm to other insects. For instance, some species of moths can produce high-frequency clicks to “jam” the sonar of bats, their primary predators.