I would just guess they are making baby grasshoppers OR they are eating up your dahlias. Steve S.

Do they eat dahlias?

The female is eating your dahlia petals while the male is getting busy. When they are both done gettin' their groove on, they will concentrate better on eating more of the flower and you will be left with chomped up blooms (I've seen them eating my blooms). I have a major grasshopper problem this year and that's why I've stopped posting pictures. Sevin dust is the only thing that really keeps them away (for me) but it's so toxic I try not to use it. Hope you don't have many of them hopping around.

Ewww. I only heard/saw about 4 grasshoppers here this year. They're a rarity, thankfully. I do like the sound they make while choppering through the air though.