Melanotus longulus is a species of beetle belonging to the family Elateridae. It is commonly known as the slender click beetle due to its elongated body shape. This insect is typically black or dark brown in color and measures around 10-15 millimeters in length. Melanotus longulus is known for its ability to produce a clicking sound by snapping its thorax against its abdomen, which is used as a defense mechanism to startle predators.