Mid-Summer Flower Power in the Blue Ridge

Although there are always some flowers present during the warmer seasons, late-middle summer (late July/early August) seems to provide a wealth of flowers for the insects and birds that depend on nectar and or pollen for their nutrition.  Since we specifically plant perennials and shrubs to attract butterflies and birds, this is an exciting time of year to admire both the beautiful flowers and the pollinators they attract.   We have about 130 species of plants in our 2 acre yard, some planted and some natural.  The colors and shapes of flowers are a direct result of co-evolution between the plants and animals they seek to attract to carry out reproduction.

Due to the cool mornings in the Blue Ridge, butterflies usually become active after 10 am but can raise their body temperatures by basking.  The common buckeye is famous for sitting in a sunny spot with out-stretched wings to warm up.  This would seem to make it a target for hungry birds; the large eye spots seem designed to deflect the attack of such predators away from the most vulnerable body parts.

Monarchs are everyone’s favorite butterfly and we eagerly watch for their arrival.  This monarch is finding nectar on a blazing star or Liatrus in our hillside garden.  The males engage in aggressive behavior and the females lay eggs on the milkweeds.  This late stage caterpillar is feasting on a common milkweed which planted itself in our yard from seeds blown from a neighboring field.  The bright colors of monarchs advertise their toxicity gained from eating milkweeds as larvae.  An unrelated viceroy butterfly is a close Muellerian mimic (toxic model and toxic mimic) of the monarch (but note the curved line in the hindwings); it is poisonous due to its larval diet of willows.

A  much larger mimicry group is found among the “black and blue” swallowtails.  The toxic model is the pipevine swallowtail; the male has a striking iridescent blue color on the dorsal surface of its hindwings and a pattern of large orange spots on the ventral or outer surfaces.  A group of swallowtails and brushfoot butterflies have a Batesian mimicry complex (toxic model and tasty mimics) based on this pattern.  One mimic that is commonly seen is the black swallowtail; this male is not a close match on the dorsal surface ( the female has more blue) but has a very similar ventral hindwing pattern with orange spots (but in a slightly different arrangement than the pipevine).  Other mimics are the female black morph of the tiger swallowtail, the spicebish and palamedes swallowtails, the red spotted purple, and the female Diana fritillary.  Learning to tell these species apart is a challenge and it is easy to see how the birds must also be confused!

You will often see a number of tiny butterflies flying rapidly from flower to flower.  These “skippers” can be very common but are quite difficult to identify.  The species shown here, the sachem, which favors the flowers of verbena/vervain is clearly distinguished by a large dark rectangle on the hindwing.

Watching the hummingbirds is great fun and they are attracted especially to red tubular flowers.  Their favorites include the native coral honeysuckle and bee balms or Monarda.  But they will avidly drink from flowers of the exotic butterfly bushes of any color and rose of Sharon ( which is unusual among mallows since it provides a nectar reward rather than just pollen to insect flower visitors).

So let us savor the flowers of summer and their remarkable animal pollinators.  They are one of the great joys of the natural world which can be easily cultivated in our gardens.