Syrphids (flower flies, or hover flies) can be distinguished from other flies (Diptera) by wing markings. Nearly all species of Syrphidae have a spurious (false) vein, a thickening in the wing that causes a discolored streak that resembles a vein unless examined under magnification. The spurious vein occurs nearly parallel with and between the third and fourth longitudinal veins. Note the top-most (marginal) vein (costa) is not considered a longitudinal vein. Credit: Comstock JH. 1897. A Manual for the Study of Insects. Comstock Publishing Co
