top of page
  • Amanda

Rabbitbrush Central Station

It's the start of a new season and a new miniseries: "Rabbitbrush Central Station". Rabbitbrush is that grayish bush covered with bright yellow blooms that grows along western roadsides in September. You've definitely seen it. Though not considered very classy, it's a cosmopolitan kind of plant: widespread, adaptable, showing up in all kinds of settings--especially where there's been a little disturbance. And just like Grand Central Station, you'll meet all kinds of characters coming and going from its many flowers, each with a story to tell. Like this bumblebee-lish thing that clearly isn't a bee upon closer examination. It's a repetitive tachinid fly. What an odd name! And an even odder lifestyle. It might just look like a nectar-sipping bee, but if you're a moth or butterfly, watch out. She's just casually hanging around, waiting to lay her egg on a fat caterpillar, so her larva can eat it from the inside out. Ewwwww! But kind of fascinating!

Part 2. Lacewing, meet aphid. There are all kinds of chance encounters and encounters by design underneath the rabbitbrush's showy blossoms. Just like in the dark recesses of a train station, predators and prey lurk in the shadows. Here is a lowly aphid--possibly the rabbitbrush aphid, because there is such a thing--which seems to have just arrived by air, and is heading down to check out the sap situation. Who should she encounter (undoubtedly it's a she) but a lacewing. Quite friendly at first, all nectar sipping and delicate. But looks are deceiving, for the lacewing's babies are another story. They happen to be called none other than aphid lions. Voracious predators with big hooked jaws sticking out of their heads, who regularly dine on aphids, but will also take on much larger insects before maturing into the demure adults that seem so friendly at first...

Part 3. Now here's more of what you'd expect on a flower: a bee gathering pollen. But wait a minute, upon second thought it doesn't look quite right. Eyes too big, stripes too few, and only two wings?? Just like at a big train station, the typical traveler is never typical. This drone fly with a long name--Eristalis nemorum is a bee impostor, but nothing really sinister about it. It's stingless, just dressing this way to scare off would-be trouble makers.It sponges up the nectar, spreads a lot of pollen in the process, and is generally what we think of as a good guy. Perhaps not the most caring parent, though, it lays its eggs in the water and flies off. Unlike the doting bees who tend the queen's young, each with its own apartment in the colony. But who's to judge? The next generation of drone flies seems to have turned out just fine.

Part 4 in the miniseries. First to show up, last to leave. The European honeybee is just like the hard working men and women who ride the late train home and the early train to work the next morning. Patiently, systematically visiting one flower after the next, the humble worker bee uses its proboscis like a straw to suck up nectar until its stomach is filled. Then back to the hive, to regurgitate it to a bee from the honey processing group. Then the worker bee is off again to the rabbitbrush, this time to collect pollen, which it stuffs into its little leg panniers. Then back to the hive, to hand it over to a bee from the nanny group, which specializes in feeding the protein-rich pollen to the queen's babies--their brothers and sisters. It's quite the organization the bees have: efficient, full of purpose, productive. So successful, in fact, that there are more honeybees on the rabbitbrush than any other kind of visitor. Not that they have more fun, but it's a heck of a business model.

Part 5 in "Rabbitbrush Central Station". There's always something interesting happening among the bright flowers here in the early fall. Some patrons are showy, seem to like to be noticed. Maybe it's because they have nothing to be afraid of, confident in their ability to sting or at least look like they sting. Others hide in the shadows, and sometimes they're up to no good, looking to prey on the unwitting. What about this bright beetle butt? It's definitely one of the 80 or so ladybug species in Colorado; there's a good chance it's one of the 70 natives we have here. But it's not going to make a positive ID easy, so all we can do is speculate. It's probably chewing on an aphid or scale since it's down in the floral axil. Possibly there to hook up with a member of the opposite sex, since the neighborhood is a great one for kids to grow up in. That's the way it is with widespread, native species like rabbitbrush. They draw all kinds of prey, which bring all kinds of predators, and before you know it, you have a dynamic, integrated, and growing community. Now that's an economic model that makes sense!

Part 6. What a cast of characters visited the rabbitbrush--aka the train station to continue with the metaphor--this September! And that doesn't even include the butterflies, moths, gnats, tiny wasps, and grasshoppers that surely passed through. A weedy plant that has a nasty smell to it, it's aptly named rubber rabbitbrush. Something that's not of much value to people, a plant that's featured in the weed-sprayer's Bible: "Weeds of the West". To a bug that likes flowers, natives and nonnatives alike, this plant is a welcome way-station. There's nectar, there's shelter, there's opportunity. Just count the tachinid flies, lacewings, and ladybugs. The aphids, bees and bee impostors. And whatever this fly-moth-wasp creature is. Could it be Poecilanthrax willistonii? An impressive name for an impressive member of the fly order that was originally named simply and ominously Anthrax willistonii. Of course, this bee fly who belongs to the Bombyliidae family has an interesting backstory. For the most part, each family member begins life inside the body of some other type of insect, where it feeds and grows up in comfort, only to emerge as an adult, with a new set of values: "I'm going to be a vegan from now on!"

Ahh, the rabbitbrush. Between it, its visitors, and the internet, I've taken a deep dive into another world. A tiny glimpse of the amazing complexity of Nature. I didn't even have to go to Costa Rica, or up onto the Forest to experience it. This drama has been going on every September, right outside in my weedy backyard!

#insects #ladybugs #rabbitbrush #entomology #naturelessons #yourlandexplained #colorado #outdoorlearning #environmentaleducation #naturalhistory #ecology #economics #honeybees #pollinators #droneflies #syrphidflies #bees #colorado #nature #lacewings #aphids #bugs #botany #wildflowers #tachinidflies #september #foodweb #parasitoids #nonatureappropriation

bottom of page