Tuesday, July 16, 2013

Cicadas, Monarchs, and June Beetles in July

Some insects are easy to identify, like the first summer sounds of cicadas a few days ago.

Also the first sighting of a monarch butterfly in the garden, with a fresh pair of wings, feeding on newly opened flowers of swamp milkweed. Maybe the garden will serve as nursery for the next generation of Monarchs, ultimately leading to the late summer generation that will fly all the way back to those few acres of forest in the mountains northwest of Mexico City, where the whole eastern population overwinters.

But what's that large insect flying low over the grass in the frontyard? A few showed up last week, and now there are maybe six or seven that circle and hover, but refuse to stay still long enough to allow a good look.

No, they aren't those scarily named cicada killers, or bee flies, or hoverflies.

Caught in my daughter's butterfly net, the insect revealed itself to be a scarab beetle, specifically a Green June Beetle. The southern species is called a Fig Beetle, after its taste for the fermented juice in damaged fruit.

Here's a description from the Penn State website of their summer flying habits and one-generation-per-year approach to perpetuating themselves:
"Females fly over the turf’s surface early in the morning, while males fly from mid- to late morning. Females produce a substance that attracts the males to them prior to mating. After females mate, they dig into the turf to lay a cluster of 10 to 30 eggs in a compacted ball of soil about the size of a walnut. Females prefer moist organic soil. The eggs are nearly round, about 1/16 inch in diameter, absorb soil moisture, and hatch in 10 to 15 days. The grubs are nocturnal feeders and consume decaying organic matter. Larvae molt three times until they reach the third instar. As cool fall temperatures arrive, the nearly mature, 1½-inch third-instar grubs dig deeper in the soil to overwinter."


2 comments:

Pat Palmer said...

We've so far seen just one Monarch on the milkweed in our back yard. And two tiger butterflies (yellow and black). Not as many as last year, for sure.

Pat Palmer said...

As kids, we always just called them "June bugs".