Odonata Insect wing

costa (c) – @ leading edge of wing, strong , marginal, extends apex of wing.
subcosta (sc) – second longitudinal vein, unbranched, joins c @ nodus.
radius , media (r+m) – third , fourth longitudinal vein, strongest vein on wing, branches, r1-r4, reach wing margin, media anterior (ma) reach wing margin. ir2 , ir3 intercalary veins behind r2 , r3 respectively.
cubitus (cu) – fifth longitudinal vein, cubitus posterior (cup) unbranched , reach wing margin.
anal veins (a1) – unbranched veins behind cubitus.
a nodus formed second main vein meets leading edge of wing. black pterostigma carried near wing tip.

the main veins , crossveins form wing venation pattern. venation patterns different in different species. there may numerous crossveins or rather few. australian flatwing damselfly s wings 1 of few veins patterns. venation pattern useful species identification. anisoptera settle wings held out sideways or downward, zygoptera settle wings held together, dorsal surfaces apposed. thorax of zygoptera oblique when held in way wings fit neatly along top of abdomen. not appear held straight in butterflies or mayflies. in few zygopteran families wings held horizontally @ rest, , in 1 anisopteran genus (e.g. cordulephya, corduliidae) wings held in typical damselfly resting position. adult species possess 2 pairs of equal or subequal wings. there appear 5 main vein stems. nodus formed second main vein (subcosta) meets leading edge of wing. in families conspicuous pterostigma carried near wing tip. identification odonata can based on venation. confusion lacewings (order neuroptera) have many crossveins in wings. until years of 20th century odonata regarded being related lacewings , given ordinal name paraneuroptera, resemblance between these 2 orders entirely superficial. in anisoptera hindwing broader forewing , in both wings crossvein divides discoidal cell triangle , supertriangle.