Small and Essex Skippers may have gone by August but most butterflies will still be around in significant numbers.
Most damselflies will have disappeared although the Blue-tailed Damselfly and the Beautiful Demoiselle should still be around. August is the best month for spotting the hawker dragonflies; Migrant Hawker and Southern Hawker will be common and a few Brown Hawkers will be about. As the hawkers all seem to spend most of their time in the air they can be difficult to identify unless they settle.
There are unlikely to be any new plants flowering in August although many of those that started earlier will be still in flower.