Busy Bees and growing trees

This week began with September peaking its head around the corner while we peaked at the maples’ new root growth. It was interesting to see some of our predicted root response strategies play out in real time. These roots are so predictable, how un-virgo of them. We also spent some time buzzing around flower beds and visiting the arboretum’s bee hives to get a look at the Apidae species responsible for pollinating lots of our plant pals. Keep reading for a more detailed review of the maples’ current root stats and a friendly introduction to some of the organisms that danced their way into September with us.

A fourth tracing session for the maples

Compared to what we saw last week with the magnolias (little to no new roots in the treated trees for both species), some of the maples had more of a growth spurt. New roots were only traceable in the silver maple species, which was expected, as these are the waterlogging tolerant species within our congeneric pair of maples. On the other hand, or maybe more accurately described: in the other pot, the treated sugar maples showed no new roots. Below you can see a comparison between a waterlogged sugar maple (left) and silver maple (right).

How are the tolerant silver maple roots responding differently than the tolerant star magnolia roots and what can this tell us about possible root strategies to deal with waterlogging stress? I’ll make one more call-back to last week’s blog post (apologies to the avid readers out there who are already keen on all of this info, but it’s wedding season and I’m trying to make it easier for those who were too busy doing the electric slide last weekend to check in). Okay, calling back my call-back, last week I mentioned the root strategy the magnolias deploy: die-back of roots when waterlogged, followed by a new flush of growth during the recovery period. The silver maples are doing something different. They are riders. They ride or die for their roots.

“Please stop trying to appeal to the youth with the trendy lingo and just tell us what’s going on with the roots.” Noted! The silver maples are somehow mitigating the root tissue damage that would typically occur under waterlogging stress. This not only allows them to maintain roots during waterlogging, but also allows them to immediately recover photosynthetic rates after waterlogging conditions cease. There is no lag time. The silver maples don’t have to sit on the bench and go to physical therapy for a couple of weeks before getting back in the game. As for the star magnolias, they have to sit out some of the season like Derrick Rose after that first knee injury. I don’t know if Derrick is still injuring his knee, but hopefully he recovered and photosynthesizing at full capacity just like our star magnolias are expected to do.

Above is a control silver maple (left) and a waterlogged silver maple (right). Looking at the blue tracings, you can see that both trees have a similar amount of new root growth. How are the silver maples mitigating tissue damage? We don’t know, but we can’t wait to find out! The stress tests we’re running to look at lipid oxidative damage and peroxidase activity should give us some insight.

Getting familiar with the pollinators

On a quest to help Sarah conquer her fear of stinging insects, we turned our attention to bees, which are arguably the cutest stinging sister amongst all the other species in the order Hymenoptera. Hymenoptera is one of the largest insect orders (although much smaller than Coleoptera which you will be introduced to later in this post), and it includes bees, wasps, ants, hornets, and the like. Females develop stingers from modified ovipositors (egg laying organs). Another interesting detail involving Hymenoptera population dynamics and reproduction: fertilized eggs result in females and unfertilized eggs result in males. Just like we've seen with our caterpillar lab pets, bees, wasps, and ants have four life stages: egg, larva, pupa, and adult. Bees are distinguished from other members of Hymenoptera because of the branched hairs (plumose hairs) they have covering their bodies.

This being my first foray into the world of bees, I was surprised to find out just how many families and species there are. The families include: Apidae, Megachilidae, Halictidae, Andrenidae, Colletidae, Melittidae, and Stenotritidae. Apidae is the largest of these families, containing over 6,000 species alive today. Some of its members you will be familiar with. Have you ever come across a fuzzy bumble bee? What about a carpenter bee? Surely you've had honey before, and you can thank the honey bee for that! Below are some of the Apidae species we came across this week:

Brought to North America by European settlers, the honey bee (Apis mellifera) quickly became a staple in American culture. I plan on diving into this specie's history in a future post. Image source.

We had fun with an unidentified bumble bee species (Bombus sp.). I didn't snap any pics of our friends this week but I'll be more vigilant next time so that we can get an ID on these ladies. Image source.

Last but not least, an unidentified carpenter bee species (Xylocopa sp.)... All we know about this one is that she really related to Tim Allen's character in Home Improvement. Image source.

Above you can see Marvin and Sarah petting bumblebees and some of the honeybee hives at the arboretum. Marvin was immediately stung as we approached the hives, so I guess our exposure therapy tactics could us some work. Don't let this deter you from friendly relations with bees! They are going about their business and won't bother you. One unlucky lady just happened to get caught in Marv's hair, and in a panic to escape, she stung him.

Beetles and Co.

A look at some of the other forest creatures we met this week:

This is a hermit flower beetle (Osmoderma eremicola). It's a scarab type beetle, in the family scarabaeidae.

What a perfect time to briefly explore the vast world of beetles. Grouped in an order named Coleoptera containing over 350,000 species, beetles hold the award for the most species diverse group of insects. Any insect with hard wing covers is included here, but no softies are allowed. Coleoptera includes 4 suborders, 17 "superfamiles" and 168 families.

Look here for a short article on the beetle family tree and DNA analysis that led scientists to reconsider the extreme adaptive radiation of the Coleoptera order. Adaptive radiation happens when lots of niche habitats and/or food sources are available in the environment, causing a species to rapidly specialize and evolve into many different species (think Darwin and his Finches, and while you're at it, take a look at this thought provoking piece on the legendary naturalist). Scientists previously believed the emergence of angiosperms (flowering plants) 140 million years ago was the cause of this rapid speciation of Coleoptera. Now? They aren’t so sure. Many beetle lineages were traced back 250+ million years ago before flowers and their tasty nectars were even around (Hunt et al., 2007). If only our hard wing-covered friend above could share with us the stories their elders passed down to them about the beginning of their existence.

The Smithsonian also offers a helpful introduction to Coleoptera, including the great (and essential) ecosystem services they provide and ways in which they assume the role of "pest" by interfering with crops and other human products.

Some of our favorite recurring guests, tiger swallowtails (Papilo glaucus)! Hey fellas, how's the family?

Did you know that caterpillars and butterflies can go into dormancy during the winter months? Me neither, until Marvin told me a couple of days ago. Look at us, learning together. Caterpillars that pupate this late in the summer will remain hidden in their chrysalides among the branches and leaves they decide to build their temporary abode on. This article from the Butterfly Conservation provides an informative summary on how butterflies and moths spend the cold holiday season in temperate regions such as ours. Butterflies and moths can go into dormancy during any one (or multiple) of their life stages (egg, larva, pupa, adult). That’s what I call independence. Can you imagine throwing your grandpa or toddler out in the snow and expecting them to survive on their own?

But wait! Before we move on from these likable larvae, I thought it would be fun to look into the etymology of some of the names in the caterpillar's lifecycle. Etymology is the study of words, their historical meaning, and how that meaning is changed or influenced over time. Ever wonder what the terms larva and pupa mean and where they come from? Then you're in luck, because I was also wondering. "Larva" originated in the 1630's and means "ghost" or "shell." Our pal Linnaeus used it about a century later to describe animals that have a life stage where they take a different form that "masks" the adult form. "Pupa" means "girl" or "doll" and I couldn't pin down a date earlier than the 1750's when, you guessed it, Linnaeus used it to describe "undeveloped creatures." Instead of calling caterpillars caterpillars, you can start calling them ghosts, and whenever you see a chrysalis, just appreciate the beauty of the hanging doll.

Remember this fun guy from last week? Marvin found another chicken of the woods (Laetiporous sulphureus) and lucky ol' me got to eat it. It's as tasty as it is beautiful.