The typical insect, known as the ‘groundplan’ insect, has 3 pairs of legs. The typical insect leg consists of several segments that are highly adapted to allow the leg to be suitable for its specific requirements. The main segments of the leg are the coxa, trochanter, femur, tibia and tarsus, some of which are not unlike the human leg. The leg segments have internal muscles, surrounded by tubular structures with articulations for joints (Ritzmann et al 2000). Insect legs are covered in sensilla, sensory organs protruding from the cuticle, that help the insect touch and taste the surface its walking on, as well as proprioceptors for ‘awareness of self’ (Steinbrecht 1996).
Insect legs are hugely diverse, with different groups of insects bearing very different types of legs that are adapted for their lifestyles.
Ambulatory legs are used for walking, for example in beetles (Coleoptera), and bugs (Hemiptera), and are known as the basic, general insect legs (Hoffman & Frodsham 1993).
Ambulatory legs are used for walking, for example in beetles (Coleoptera), and bugs (Hemiptera), and are known as the basic, general insect legs (Hoffman & Frodsham 1993).
Cursorial legs are modified for running, for example in cockroaches (Blattodea), with long, thin segments (Hoffman & Frodsham 1993).
Fossorial legs are modified for digging, for example in mole crickets (Orthoptera) and cicada nymphs (Hemiptera), with short, strong segments (Hoffman & Frodsham 1993).
Natorial legs are modified for swimming, for example in aquatic beetles (Orthoptera), with setae on the tarsi to aid in water movement (Hoffman & Frodsham 1993).
Raptorial legs are modified for grasping and catching prey, for example in mantids (Mantodea) and water scorpions (Hemiptera). These leg segments have sharp spikes and are wide for extra strength (Hoffman & Frodsham 1993).
Salatorial legs are modified for jumping, for example in grasshoppers (Orthoptera). This modification only occurs in the hind legs, and have elongated femur and tibia (Hoffman & Frodsham 1993).