Nature: Brightly colored primrose moths stunning but rarely spotted in Ohio
September 17, 2023
On Aug. 18, I was slowly cruising an Ottawa County rural lane bordering Ottawa National Wildlife Refuge. The refuge encompasses about 7,000 acres along the shore of Lake Erie, east of Toledo. Birds were my primary quarry, and I was armed with large telephoto lenses with which to photograph them.
In places, the roadsides were awash with the bright lemony blossoms of common evening-primrose (Oenothera biennis). This native plant can reach 4-5 feet in height, and sport dozens of blooms. I was keeping a casual eye on the primrose flowers, hoping to luck into a holy grail of the moth world.
Suddenly, an out of place jot of bright pink on a primrose flower caught my eye. Birds forgotten, I pulled the car off the road and ran over to investigate. Yes! It was a primrose moth sticking from the flower, and a closer look revealed yet another crammed within the blossom.
The primrose moth (Schinia florida) is a truly stunning insect. It is pink and yellow in all the right places, which helps it blend with the colors of its host plant. Further aiding in their disguise is the behavior of the primrose flower. They open toward dusk and bloom through the night. By doing so, the plant attracts moth pollinators.
After the sun rises and the day gets lighter, the primrose flowers close up. Primrose moths alight on the flowers prior to daybreak, and eventually the flower petals fold over them. The little moths are then ensconced in colorful floral sleeping bags, largely hidden from view.
Sometimes primrose moths spend their days resting upon the colorful pink and green primrose buds. The moth’s seemingly garish coloration serves it well when hiding on such colorful substrates.
The lepidopteran nut does not fall far from the primrose tree, and primrose moths live out their entire life cycle in close proximity to their host plant. Female moths lay eggs, up to 200 of them, on young primrose flower buds. Tiny caterpillars soon hatch and begin feeding on the buds.
Caterpillars grow with rapidity, molting five times over the course of their growth and emerging from each molt far larger than the previous stage. While the caterpillar is brownish during the first stage — or instar — by the last stage, it is bright pink. It has also increased its overall mass hundreds of times over the tiny first stage form.
When mature, the caterpillar climbs to the ground, finds suitably soft soil and burrows in. It overwinters and pupates in the ground and will emerge the following summer as a beautiful pink and yellow moth to commence the cycle anew.
Primrose moths seem to be rare in Ohio, and I don’t know why. I have only seen them a few times, despite having scanned thousands of primrose flowers over the years. All my moth-oriented comrades report the same lack of results. And a check of iNaturalist – the enormous citizen science database of flora and fauna – reveals relatively few Ohio records.
Perhaps the moths are just so adept at camouflaging themselves that people miss them. But bright pink and yellow winged creatures that resemble lepidopteran Teletubbies tend to catch one’s eye when they are out and about. It may be that primrose moths do not come to lights at night, as so many moths do, and thus aren’t easy to find during the nocturnal hours when they are active.
But moth-ers to our east and northeast seem to find plenty, based on iNaturalist reports. Yet common evening-primrose is also abundant in Ohio, so it isn’t a shortage of the stunning little moth’s host plant that causes its apparent scarcity in the Buckeye state.
Moth enigmas like this are not hard to find. Their diurnal counterparts the butterflies are far better-known and studied. In comparison, moths are very poorly known, even bright pink and yellow ones. But only about 140 butterfly species have been found in Ohio, while we host at least 3,000 moth species and probably far more species than that. Most moth species remain largely unstudied.
If you wish to learn more about the fascinating world of moths, I am giving a program titled "Mysterious Moths" at the Grandview Heights Public Library at 6:30 p.m. Tuesday. The library is at 1685 West First Avenue, the event is free, and all are welcome. Copies of my new book, "Gardening for Moths," written along with Chelsea Gottfried, will be available.
Naturalist Jim McCormac writes a column for The Dispatch on the first, third and fifth Sundays of the month. He also writes about nature at jimmccormac.blogspot.com.