Cricket species is hard to get distinguished and now Indian researchers are finding a way to analyse the species diversity using its chirp. The scientists are establishing an acoustic signal library, which can help in tracking the diversity of these insects.
Despite Morphology based taxonomy has helped in big way to recognise and establish species diversity, it is often not sufficient in delimiting cryptic species – a group of two or more morphologically indistinguishable species (hidden under one species) or individuals of the same species expressing diverse morphological features (which are often classified into multiple species). This has often led to overestimation or underestimation of species diversity.
Ranjana Jaiswara, a Fellow at the Department of Zoology, Panjab University, is working with a team to establish a field crickets acoustic signal library. They hope this could be a non-invasive tool in species diversity estimation and monitoring. The library is envisaged as a digital one and can use it even through mobile applications for automated species recognition and discovery as well as documentation of new species of crickets from India.
The researchers use acoustic signals, phonotactic behavioural data and DNA sequences in studying species diversity. They used field crickets as a model organism. In her research published in Journal of Zoological Systematics and Evolutionary Research, she has shown that species-specific bioacoustics signals are a highly efficient and reliable tool in marking species boundaries. It can also help in accurate estimate of species richness and diversity in any geographical area.
Dr Jaiswara documented that the issue of cryptic species can be addressed using bioacoustic signal and statistical analyses. This approach has led to the discovery of several cryptic and new species of crickets from India, South-Africa, Peru and Brazil.
Field crickets are one of the most commonly used model organisms in the field of behavioural ecology, neuroethology, acoustics and experimental biology as they are unique in their ability to produce loud acoustic signal. They produce the sound by rubbing of highly specialised forewings against each other.