Features of the insects: W: wings present; body without a narrow waist; antennae shorter than the body. X: no wings present; body covered in hairs. Y: wings present; body without a narrow waist; antennae longer than the body. Z: wings present; body with a narrow waist. Key: 1 (a) wings present .................. go to 2 (b) no wings present ............... Thysanura 2 (a) body has a narrow waist ....... Hymenoptera (b) body without a narrow waist ... go to 3 3 (a) antennae longer than the body . Orthoptera (b) antennae shorter than the body Diptera