Strategic Flowering

If you look up at the bare branches of some trees along the Greenway, you may see the beginnings of tiny green buds of leaves beginning to burst. Other trees, however, may bear full-fledged flowers on their otherwise naked limbs. Why do some trees flower before sending out leaves, while others don't flower until much later in the season?

Redbud is a common tree that produces
flowers before leaves in the spring.

Trees, after they lose their leaves for the winter, maintain a supply of carbohydrates and sugars throughout their dormant period, which can be drawn on for producing new growth when the weather warms up. Some trees, known as hysteranthous, use those initial reserves to produce flowers, while neighboring species may not flower until after their leaves have grown (proteranthous).

This maple already flowered and has set seeds by the time
the leaves began to appear.

There are many advantages to flowering early: for wind-pollinated flowers, the absence of leaves allows pollen to move freely and find flowers without interference, while flowers that rely on bees and other insect pollinators benefit from greater visibility and access, as well as being in high demand for these hungry helpers while other flowers are scarce. These trees get the hard work of reproduction over with quickly, and can focus on growing and replenishing their stores throughout the rest of the growing season.

This strategy is not without its risks, as many gardeners are keenly aware. A late cold snap can damage or kill the flowers that the tree just expended precious energy to produce, forfeiting the opportunity to reproduce this season.

Not all trees flower early: Catalpa waits until its
large leaves are developed before flowering.

Trees, like all other living organisms, have developed an amazing variety of strategies for life and reproduction, all of which have been successful (up to this moment, at least!). Changing climate will bring new challenges and pressures, and those species best able to adapt will come out ahead.  Meanwhile, such diversity presents a spectacular show for us humans to enjoy throughout the seasons.

What is that Bug?

Gather 'round, friends. I'm about to rock your world.

A couple weeks ago the annual Day of Insects was held at Reiman Gardens in Ames. Among the presentations (ranging from an update on the endangered Rusty-patched Bumblebee to a business based on crickets as people-food) was a demonstration of the Insects of Iowa website by its creator Jim Durbin.

This site has photos and records of the insects that can be found in Iowa, with detailed records of surveys and sightings. But a new (and utterly amazing) feature is the photo ID:



You just upload a photo, crop it to the bug you are trying to identify, and click "Submit for Identification." After a few moments, the program recommends species with a match probability:

The website uses AI that has been "trained" on local species; it is particularly good at moths and butterflies. Rather than leafing through hundreds of pages of photos or drawings in a printed guide, or trying to search online using descriptive keywords, the website does all the work!

It's not flawless; I had poor luck with bees (the two examples below don't seem very promising); perhaps the features that are necessary to identify bees are not always easy to capture in photos? Or maybe the AI has not been trained on enough photos of bees to reliably identify all the species.

I'm not sure what this one is, but I'm
fairly positive it's NOT Apis mellifera,
the common honeybee.

Again, this one is definitely NOT Agapostemon
virescens, a metallic green bee. But a long-horned
Melissodes seems plausible.

Even if the program doesn't identify your photo with 100% accuracy, it often provides enough information to get you started on the right track. You can click the linked results to see photos of the species on the site, or search for the scientific name to see other photos and determine how closely that match.

This guy, for example, was clearly not a Hummingbird Clearwing Moth, and Yellow-Collared Scape Moth didn't seem right either. But #3, the Large Clover Casebearer, looks pretty close (even if the ID was only 2.55% confident). 

Give it a try! Do you have a photo of an insect that you've never been able to identify? Or maybe head out to the yard and find an unidentified friend hanging out in your garden. You might get a species, or maybe you will just be able to narrow it down to a genus and refine your search through other means. But it's a great tool to help learn more about the insects that share our neighborhood.