Winter Carnivore Cleanups – Bonus Round

Backstory: it’s January, we don’t have any distractions, and the plants need us. Therefore, it’s time to discuss methods to clean up carnivorous plants for spring. For details, go back to the beginning.

If you’ve been following the crowd and cleaning up your Sarracenia pitcher plants, there’s an added bonus for keeping them outside through their growing season. Just like animals, carnivorous plants have to deal with the byproducts of digestion: namely, everything that doesn’t digest, which includes shells, fat bodies, stomach contents, and the occasional wristwatch. With carnivores with beartrap or sticky traps, such as Venus flytraps, sundews, and butterworts, those leftovers are left to be washed off during the next rain, and many take advantage of those remains as bait to attract new prey. (This is why some of the most common prey items in Venus flytraps tend to be spiders: jumping and crab spiders look at the empty shells of flies and other insects as an opportunity for an easy meal, and set off the same trigger hairs responsible for that now-empty insect shell being there in the first place.) With all four of the genera commonly listed as “pitcher plants,” though, instead of developing an anus or other way to flush those parts out of a trap, the plant instead just grows new traps, and the old, prey-filled traps shrivel up and die, to be replaced by new ones. Careful cutting of a dead pitcher reveals valuable information about what kinds of prey the plant attracted while the trap was still alive…if you know how to read it.

  • Garden mat or old towel
  • Plastic tub or tray (go for something with reasonably high walls)
  • Tub liner (plastic or paper)
  • Spray bottle filled with water
  • Narrow garden shears or garden scissors
  • Forceps
  • Long pin or dissection probe
  • Glass container (test tube or small jar) for holding trap contents
  • A good light source
  • Magnifying glass or dissecting microscope

As to where to get the pitchers in the first place, these tend to be available on Sarracenia undergoing winter dormancy, usually broken by wind or snow, and usually get clipped off as part of a winter cleanup. Since these are going to get tossed into the compost pile anyway, they’re perfect for our nefarious purposes. You can determine the presence of interesting contents in multiple ways: holes in the side of the pitcher from wind, weather, or bird foraging reveal insect contents, or you can fold back the pitcher lid and look inside. Alternately, you can just cut open every pitcher you get to see what’s inside, but be warned that animals ranging from spiders to tree frogs may be attempting to hibernate, at least for a little while, inside of a particular pitcher, and it’s good form to give them a chance to escape before tearing up their winter homes.

A very good way to tell if a pitcher has a significant collection of prey is to look for dead patches, sometimes called “bee burn,” on the pitcher walls. Bee burn can be caused by multiple factors, but it always involves the plant collecting too much prey for it to digest all at once. Look at it as plant indigestion. In this case, the bee burn comes from an especially dry October, where Dallas humidity was so low that the plant simply couldn’t draw up enough water in its pitcher to break down everything, but the trap itself continued working at maximum efficiency. The bad news is that this surplus of material eventually killed the trap walls, leaving that distinctive burn. The good news is that we KNOW that the trap will be full of all sorts of interesting things.

To start, you’re going to need a decent work space and proper tools. As far as the workspace is concerned, do so inside of a plastic tub, a Sterilite container, or something else with reasonably high walls. In the process of cutting open pitchers, things WILL fall out, and you want them enclosed so they don’t end up on the floor or in your lap. In addition, you’ll probably want some kind of liner or barrier both for contrast and to pick up trap contents from the tub before you start work: plastic sheeting works well, but my personal favorite is baking parchment. (Separation layer for epoxy work, quick-and-dirty paint palette, bug part consolidator: is there anything baking parchment can’t do?)

Another thing to consider is exactly how…erm, gooey you want your trap contents to be. Especially after a stout rain, those trap contents can be rather saturated, and it’s not a bad idea after trimming them off to let them sit somewhere where they can drain a bit. Even after, the contents remain quite waterlogged for a while, so setting pitchers in front of a fan or heating vent or on a sunny windowsill for a few days isn’t a bad option. This also gives a chance for opportunists such as ants or spiders to find somewhere else to go.

Once you have your container and liner ready, it’s time to start work. Get out a pair of sharp scissors, preferably with narrow blades, and cut off the lid end of the pitcher. This isn’t just to make the rest of the trap easier to work with, but also because scissor blades have a tendency to get caught on the edge of the pitcher lip when cutting further. Set it aside, look at it from the insect’s POV, use it as an all-organic finger puppet: the possibilities are endless.

At this point, check the placement of where the layer of trap contents starts, and prepare to start cutting to free it. From this end, this may not be all that interesting, but sometimes interesting insects get caught in the pitcher after the official end of the growing season, and now is the time to make sure you don’t have something like a paper wasp or honeybee that’s still alive and peeved at its situation.

From the end of the cut pitcher, slowly and carefully cut lengthwide along the pitcher. Taking it slow and easy works for multiple reasons: you’re less likely to damage something particularly significant or interesting, you’ll be able to feel tension on the blade as you’re cutting, and you’re less likely to put tension on the pitcher and fling those contents in your face and all over your best clothes. (I guess I should have said “don’t wear your best clothes while cutting up dead pitcher plant pitchers,” shouldn’t I?)

Just because it’s shown this way doesn’t mean you should do it this way: make another cut on the other side so that your trap’s contents fall onto your liner and don’t go flying. If your pitcher plant had a good year, you’ll have quite the bolus of insect parts, as well as the occasional bones from small vertebrates such as frogs or geckos. (Both frogs and geckos are especially good at getting out of a Sarracenia pitcher, so any bones probably come from ones dying of other causes.) If that pile is completely dry, it’ll probably adhere and make chunks, and those can be broken up by gently spraying the chunk with a little water and then separating the parts as the lump softens.

One thing that becomes very obvious when looking at pitcher contents that while Sarracenia are opportunists, many tend to capture one type of prey than others. For instance, red pitcher plants (Sarracenia rubra) and their hybrids tend to catch a disproportionate number of ants. These pitchers in this exercise are from hybrids of white pitcher plants (Sarracenia leucophylla), and S. leucophylla is especially good at attracting and capturing nocturnal insects such as moths and click beetles. This trap caught a lot of moths, as is obvious by the number of wings still recognizable as such.

At this juncture, you have several options. If you have further plans for the evening, slide these parts into a test tube or glass jar to save them for later. (If your parts are still gooey, put the test tube or jar in a refrigerator so the parts don’t grow mold.) Alternately, if you’re ready to get going, take a pair of forceps, a dissecting probe, and whatever magnifying option suits your fancy and separate and sort the assembled parts. With a bit of entomology knowledge, you’ll soon recognize legs, digging limbs, and elytra (the carapace atop a beetle’s back to protect the wings and conserve moisture) and be able to gauge how many insects a typical pitcher plant captures over a growing season.

And to quote Canada’s answer to Doctor Who, “it really is just that easy.” It’s just like taking apart an owl pellet, but with considerably less owl vomit. If you don’t have any trimmed pitchers this year, well, that’s just something to look forward to doing the next time you’re cleaning up your Sarracenia.

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