In celebration of National Pollinator Week, June 19–25, here’s a reminder that wildflowers aren’t just for pollen, nectar, bees, pretty butterflies, and hummingbirds. Some are for eating.
Many native plants, especially milkweeds, provide sustenance for growing insects, so while some first-time gardeners expect their milkweed patches to be monarch-only establishments, that’s not the case.
“That’s the purpose of every single solitary plant; to be eaten,” said Sandra Schwinn, who, as a Tulsa school teacher and statewide Monarch Watch volunteer, has for decades educated people about planting milkweeds to–in many cases–watch insects eat the plants down to the stem.
Milkweeds are a natural choice for pollinator garden first-timers. The flowering plants are the flagship pollinator plant because they are necessary to host monarch larvae and provide nectar for the colorful adult butterflies that symbolize pollinator initiatives across the continent.
Most gardeners love the idea of watching those big green, black, and yellow monarch caterpillars munching away.
But hoards of other critters sometimes arrive to munch on the leaves and stems or suck the life out of their milkweeds. Among them are other caterpillars, beetles, and tiny aphids.
Schwinn recommends people open a book for all the answers about milkweeds and what eats them; “Milkweeds, Monarchs and More: A Field Gide to the Invertebrate Community in the Milkweed Patch.”
“I mention that book in my presentations a lot. It’s a wealth of information, and it has a lot of big pictures, so it’s just as good for kids as it is for adults,” she said. “It tells about each and every kind of insect that can show up on your milkweeds.”
Schwinn described a drama of predator and prey and gruesome scenes that can take place at a microscopic level along the branches of milkweed plants.
Oleander aphids, non-native invaders of Mediterranean origins, are small yellow bugs that swarm milkweeds and can suck the sap of life from small plant or sicken it by coating the leaves with so much sticky excrement it blocks the sun.
But Schwinn said the only time to interfere is when a plant looks like it is nearly dead. Even then, she said a few strong rinses with the garden hose or water with little dish soap might be all it takes to save a plant.
Pollinator gardens are not the place to use insecticides, she said.
“I had aphids all over a swamp milkweed, and I just watched as the ladybugs showed up on one end and started cleaning them up,” she said. “They got to the other end, the lacewings showed up, and the aphids were gone.”
Small but rotund ladybug adults and their wrinkly larvae both feed on aphids. Tiny lacewings, slender as a sewing needle with oversized wings, also eat the aphids. Both of the aphid-eaters are, in turn, eaten by larger predatory insects and birds.
The aphids also attract a tiny parasitic wasp so small it can deposit eggs inside aphids. When an egg hatches, the tiny larva develops inside the aphid, its first meal. It leaves behind a brown “mummy” aphid.
Schwinn said striped garden caterpillars and milkweed tussock moth caterpillars also need milkweed to survive, and there is nothing wrong with watching those worms munch away. Many pollinator garden veterans plant a variety of different milkweeds, so any one of the varieties might be ready when monarchs happen by.
Schwinn said she saw summer monarchs laying eggs on milkweed this month. Recent rains have boosted new shoots, and the butterflies seem to be taking advantage.
While monarchs and milkweed varieties are headline-grabbing pollinators, Schwinn said all native flowering plants serve a role for nectar-gathering insects, from beetles and bees to butterflies and hummingbirds, and the food chain for many starts not only with nectar and pollen but the leaves and stems of wildflowers as well.
