Butterfly (Lepidoptera: Nymphalidae) and Syrphid fly (Diptera: Syrphidae) on dandelion The butterfly is probably Issoria lathonia (in Swedish: Storfläckig pärlemorfjäril). The wing breadth is 36 to 47 mm. The caterpillars feed on violets. The syrphid fly is on right side of flower. A common housefly (Diptera: Muscidae) is at bottom left on dandelion flower (genus Taraxacum). Another butterfly is on top in background. Taken near Torsby, Sweden, in June.

Images © 1996 by John A. Byers, Chemical Ecology.