Friday, July 19, 2013

Monarchs, milkweed & beetles

I've been admiring the healthy stand of common milkweed (Asclepias syriaca) flourishing (and blooming) right now in the prairie patch (more accurately, the weed patch) at the foot of museum hill.

This area was developed several years ago as a small reconstructed prairie patch, then decimated by a city sewer project. Since then, we've just let it grow to see what happens.

Milkweed is important in the Midwest in part because Monarch butterflies lay their eggs on it, but the prime reservoir of milkweed --- farm fields --- has been drying up, paralleling the rise in use of glyphosate herbicides, which spare crops genetically engineered to resist them but kill everything else. As a result, the Monarch population has been declining steadily.

So --- since the use of herbicides is unlikely to decrease, it becomes increasingly important to plant and conserve milkweed elsewhere.

If you look carefully at the milkweed bloom here, you'll notice elegant antennae --- belonging to one of a healthy population of red milkweed beetles (Tetraopes tetrophthalmus), which emerged last week and has been feeding enthusiastically since.

As we speak, beetle affairs of the heart are progressing and eggs are being laid at the base of milkweed stems. Newly-hatched larvae/grubs will overwinter in the milkweed root system, feeding on the roots, then pupate and emerge in early next summer to repeat the process. 

A variety of milkweeds flourish in Lucas County, all favored by Monarchs --- and their own varieties of milkweed beetle.

The rarer but much more colorful "butterfly milkweed" (Asclepias tuberosa) is blooming right now in prairie remnants and elsewhere, although the insect feeding here is a bee rather than a beetle (this photo is two years old).

A little later, swamp milkweed (Asclepias incarnata) --- which prefers to have damper feet --- will burst into bloom in places like Pin Oak marsh, where this photo was taken two years ago.

But wherever they are, the Monarchs, milkweeds --- and beetles --- are our friends.

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