My original interest in wildlife often centered around mammals; as a child, I was especially fascinated by the larger ones I saw at the zoo like lions, giraffes and bears. Eventually, in my later adult life, I became a birder and then Project Noah led me to begin paying much closer attention to the insect world. Nowadays, I find almost any type of wildlife of interest and look forward to learning more about diverse species.
Investigating insects has taught me that not only are some moths incredibly beautiful – so are some beetles and dragonflies, like the two brilliant blue species described here. I first encountered the dogbane beetle (Chrysochus auratus) on the plant for which it’s named, the white-flowering dogbane (Apocynum cannabinum). This plant is also known as rheumatism root since herbalists have used it to treat that disease, as well as conditions such as syphilis, fever, asthma and dysentery. It is also known as the hemp plant and has been used to make rope.
The iridescent beetle, which measures less than a half inch and lives 6-8 weeks in summer, feeds on the dogbane as well as milkweed plants. The insects’ wings are blue-green in color and have a gorgeous shimmery shine that looks like metallic copper; depending on the light, the highlights can also look golden or crimson in color.
They have widely spaced antennae with 11-12 segments and their legs look a bit as if they end in heart-shaped pads. Their left mandible is longer than the right one and it fits into a groove in the right (why, I don’t know!).
They mate once a day during the summer and the male will stay on top of the female afterwards for some time to ensure that his sperm can fertilize eggs. After mating, the female lays her eggs on the underside of host plant leaves or on the ground. The larvae feed on roots and pupate underground. After 6-8 weeks, the adults die and we have to wait until next summer to see these little beauties.
A larger metallic blue insect is the ebony jewelwing damselfly (Calopteryx maculata), which can grow to about 2 inches. It is the black-winged males who exhibit the deep blue color on their bodies. The females are a smoky brown-gray in color and display white spots near the tips of their wings.
These damselflies have been studied extensively, so that we know they shelter among a wide variety of plants, including water plants (pickerel weed, duckweed, lilies, cattails) and land plants such as orange jewelweed, button bush, Joe pye weed and poison ivy. The adults frequently rest on low shrubs in sunlit patches.
These damselflies have a large variety of prey that include tiger mosquitoes, gnats, flies, beetles and even dragonflies. If they see you observing them, they will watch you in return, turning their heads to follow your movements
These damselflies are not strong fliers, often fluttering – even when resting on a leaf. Females will also rapidly open and close their wings if they are receptive to a courting male. If they reject the male, they will keep their wings open.
(If you click on the photo, you can see it enlarged.)
Females lay their eggs in the soft stems of water plants. And then, after about two weeks of flight, the adults pass away and we await new generations to admire. I’m looking forward to finding out if I discover any more blue jewels in the future!