In late July on our VA farm, the predominant color of the landscape is GREEN! But our 10 year old pollinator field is now predominantly yellow with the blooms of oxeye sunflower. This is a table set for the multitude of mouths of the lepidopterans (butterflies and moths), which are a prime food for birds. While some of these insects may be considered pests, many are spectacularly colored and have very interesting habits for study by the naturalist.
There are three beautiful species of large fritillary butterflies in this area. The Aphrodite from higher altitudes is only slightly different from the more common great spangled, which has a broader white band on the margins of the outer hindwing, and one less spot on the inside margin of the forewing. A third member of the genus Speyeria , the Diana fritillary, is rare in our area but a friend, Cecelia Mathis, has obtained a wonderful photo of two male Dianas with a great spangled on the flowers of a common milkweed along a remote forest road. In contrast with most sexual differences in which the male is more showy, the male Dianas are a relatively dull brown and orange color compared with the brighter black and blue female. The color of the female is even more remarkable since it appears to be a case of mimicry of the toxic pipevine swallowtail.
Some of the moths can be quite spectacular. The hummingbird clearwing sphinx moth hovers as it drinks nectar from flowers. The yellow collared scape moth lands on flowers and is apparently mimicking a wasp and thus avoiding some predation during its daytime feeding. The brown hooded owlet moth is very inconspicuous as an adult, but its caterpillar is absolutely gorgeous in yellow, black and red stripes; such advertisement usually accompanies toxicity but little is known about such chemical warfare in this species. It also appears to have head/tail mimicry by calling attention to the tail rather than the head to divert attacks by birds.
An examination of the numerous flowers in bloom will reveal a wide variety of butterflies visiting them. Some examples are the silver spotted skipper on wild bergamot, a white morph orange/clouded sulphur on red clover, and a red admiral on purple coneflower. I have also noticed a number of monarchs mating in our fields where we have thousands of common milkweeds ready for them to lay eggs. The leaves of many of these milkweeds are tender and thus attractive to monarch caterpillars since the fields were mowed for hay about six weeks ago and the plants have regrown. This is an example of how careful timing of mowing can benefit monarchs.
So in late July bird song is definitely waning, but the insects and especially lepidopterans are abundant and active for you to observe and enjoy.
Galax, VA and Englewood, FL