Study of stridulatory organs in the family heteroceridae (Insecta: Coleoptera)

The morphology of stridulatory organs for 16 species of the family Heteroceridae is described. The variegated mud-loving beetles (Heteroceridae) produce sound by abdominal-femoral movement— scraping the surface of one projection on the hindleg (the plectrum) against the surface of a series of the ridges (or ribs) on the first abdominal segment (the stridulatory file, or the pars strides). This study explores for the first-time the differences in these structures between the genera Augyles and Heterocerus. The study is based on imaging the sound-producing structures on a scanning electron microscope. The following parameters were measured: The size of the stridulatory file, the number of ridges, length of ridges, distance between ridges, width of ridges, and size of the plectrum. This study demonstrates how these parameters depend on each other in 16 species (genera Augyles and Heterocerus) and how the stridulatory organ is varied between male and female (Augyles genus). The stridulatory file consists of two types of ridges, which are named firstorder and second-order ridges. The results of this study show that the width of the ridges and the distance between the ridges depend on the sex of the insects. Thus, the value of the distance between the ridges is greater than the width of ridges in males and vice versa in females. Future studies should focus on larger samples for each species.