is unbranched and joins the costa at the nodus. Radius and Media (R+M) – third and fourth longitudinal veins, the strongest vein on the wing, with branches R1 to R4 reaching the wing margin; the media anterior (MA) also reaches the wing margin. IR2 and IR3 are intercalary veins behind R2 and R3 respectively. Cubitus (Cu) – the fifth longitudinal vein, cubitus posterior (CuP) is unbranched and reaches the wing margin. Anal veins (A1) – unbranched veins behind the cubitus. A nodus is formed where the subcostal vein meets the leading edge of the wing. The dark pterostigma is carried near the wing tip. The main veins and the crossveins form the wing venation pattern. The venation patterns are different in different species and can be useful for species identification. Legs The legs are used for the capture and handling of prey, for grasping females, for repelling rivals, and for clinging while perching; they have long spines on the femur and tibia. Abdomen The abdomen is long and cylindrical in many species, but in the Libellulidae it may be relatively short and broad. It has ten segments (S1-S10), terminating with appendages on S10. Males have both upper appendages (cerci) and lower appendages (epiprocts in dragonflies and paraprocts in damselflies), which are used to hold females while mating; these are also termed claspers. Males also have secondary genitalia (including the anterior lamina, hamuli and posterior lamina) on S2 and S3. Female damselflies and some dragonflies have a strong ovipositor on the underside of S8 and S9, but in many dragonflies the egg-laying apparatus is merely a spout, a basket, or a pair of flaps. Some species have foliations (leaf-like extensions) on S8 and/or S9. Nymph The aquatic nymph (larva) has a stockier, shorter, body than the adult. It lacks wings, the eyes are smaller, the antennae longer, and the head is less mobile than in the adult. The mouthparts are modified, with the labium being adapted into a unique prehensile organ for grasping prey. Damselfly nymphs breathe through external gills on the abdomen, while dragonfly nymphs respire through an organ in their rectum. Differences between dragonflies and damselflies Although generally fairly similar, dragonflies differ from damselflies in several, easily recognizable traits. Dragonflies are strong fliers with fairly robust bodies and they have wings that are broad near the base; at rest the wings are held out to the side. Damselflies tend