And so the Sarracenia growing season ends. Last week’s surprise but not completely unexpected hard frost finally put paid to the taller growth in the Sarracenia pools, and they don’t have much longer until all of them go brown and die back. Considering the weather forecast for next week, with lows pushing freezing, we’ll get a classic Sarracenia autumn: lots of brilliant color as the traps die off, and then quiet until spring.
One of the benefits of the heightened color is that the insects still around are even more mesmerized by the coloration, and the plants have no problems taking advantage of the arthropod bounty. This way, the plants get one last boost of nitrogen and phosphorus before the winter sleep, and in anticipation of large and healthy blooms in March. More than at any other time during the growing season, this is when passing by a Sarracenia stand yields the odd sound of flying insects attempting to fly or climb out of the pitchers, only to have the shape of the pitchers produce a downdraft towards the depths every time they try to fly out. The pitchers also act as acoustic horns, so that angry buzzing travels a lot further than one would expect.
And what’s in the pitchers? This time of the year, it’s usually a combination of moths and bees, both attracted by the pitchers’ fluorescence under UV and by a particularly generous secretion of nectar along the lid and lip. This year was surprising, though, because a significant number of traps also caught at least one stink bug at a time. I don’t know if they were attracted by the nectar or the promise of a hiding spot, but there’s a satisfaction in knowing that next year’s stink bug population drops every time the plants feed.