Panorpa cognata is the least frequently recorded of the mecopterans from the British Isles. Ocelli are present. It has a black body with yellow on the sides, yellow rings on the abdomen and yellow marks and head (can be brown in some individuals). Pronotum with brown central marks. The genital capsule in males (which gives them the common name scorpionflies) and the tip of the abdomen in females is a red colour. The legs are a yellowish brown in colour. It has four membranous wings with a colour pattern. The wings are transparent with more or less transparent wing tip, sometimes with dark spot, and large spots in the centre that merge, in the basal part of the wing there are smaller dark spots. Panorpa cognata has a body length of 10-12mm and a wingspan of 25-28mm.
Panorpa cognata is locally distributed in England and Wales and there is a record from Scotland.
To identify specimens form the British Isles to species level the genitalia of the male and female need to be examined.
Patterned wings: More or less transparent wing tips, or dark spot near wing tip, central spots merge forming a band approximately half the width of the wing.
Male (can be viewed without dissection): The genital capsule has callipers that are slender, diverging at the tips.
Female (internal ovipositor needs to be extracted): Anterior apodemes appear straight curving outwards towards to tip, no swelling. The tips of the arms of the genital plate are relatively wide with blunt/rounded tips.
Damp woodland and scrub; often seen on low vegetation. Often recorded in calcareous sites.