Click beetles (family Elateridae) are insects known for a distinctive terrestrial movement that often overshadows their ability to move through the air. They possess fully functional wings, and the short answer to whether they fly is yes. Although their aerial capabilities do not earn them their common name, flight is a regular and necessary part of their adult life cycle.
Answering the Core Question and Identifying Click Beetles
Adult click beetles are capable of flight, using a pair of membranous hindwings for locomotion. These delicate wings are folded and protected beneath hardened forewings, known as elytra, which are common to all beetles. Adults are characterized by their elongated, parallel-sided bodies, typically measuring between 2.5 and 18 millimeters long. Most species are dull shades of brown or black, though some tropical varieties exhibit bright coloration or bioluminescence.
The Mechanics of the Click and Why It Happens
The clicking sound and subsequent jump are caused by a specialized spring-and-latch system located on the underside of the beetle. This mechanism is situated between the first segment of the thorax (prothorax) and the second segment (mesothorax). It consists of a backward-pointing, spine-like projection on the prosternum that fits into a corresponding groove on the mesosternum.
To initiate the click, the beetle hyperextends its body, arching its head and thorax backward to lock the prosternal spine into the groove. Muscle contraction loads elastic energy into a soft, internal cuticle, similar to cocking a mechanical spring. When the tension is released, the spine snaps into the groove with an audible click, hurling the beetle into the air. This move is used primarily for self-righting when the beetle is overturned, but it also serves as a defensive tactic to startle predators. The acceleration achieved can exceed 300 times that of Earth’s gravity, launching the beetle up to 20 body lengths high.
Flight Behavior and Purpose
Click beetles use flight for essential life functions, including dispersal and reproduction. The membranous flight wings are deployed from beneath the protective elytra when the beetle needs to travel longer distances. Flight is the primary way adults locate mates and find suitable host plants for feeding or laying eggs.
Most species are nocturnal, concentrating their flight activity during the night hours. This nocturnal habit explains why they are often observed near artificial light sources, to which they are strongly attracted. Once they land, the beetles fold their flight wings back beneath their hard wing covers, relying on walking or the click-jump for smaller movements.