Wednesday, October 2, 2013

What's On That Hibiscus Seed Pod?

A very beautiful plant that flowers in July and August around here is the mallow flower, in the hibiscus family.  These plants can tolerate swampy conditions--this picture is of a plant on the edge of the pond behind our Museum:
On the Museum grounds I've seen mallows with the above pink color, and also white flowers with a burgundy center.  Here are the buds before the bloom opens:
The plant is so lovely, I thought I'd try my hand at propagating--something I've not had much success at, so more as an exercise in futility than anything else, I thought I'd try it.  With the kind permission of our Horticulture Curator (thanks Bruce!) I snipped off several seed pods, and dropped them into a plastic bag.  I shook the bag until the seeds fell out of the pods ending up with a handful of seeds about the size of peppercorns:
To my surprise, I noticed tiny little beetles crawling around, coming out of holes in the seeds, and flying off.  Can you spot the tiny beetle?:
Well, I'm pretty sure these are hibiscus beetles.  The adults feed on the flower's pollen and lay their eggs on the seed capsule.  The larvae bore into seeds where they grow and develop.  In the autumn, adults emerge--the hole in these seeds are about 1.5 - 2 mm in diameter.  I photographed this beetle right before it unfolded its elytra (top hard wing covers) and flew off.  You can see the membranous underwings start to unfold at the bottom of the carapace:
The little hibiscus beetles were not the only creatures I found on the seed pods--with their bright colors and orange eyes, these bugs were a lot more obvious:
These are Niesthrea louisianica, a type bug (a true bug, not a beetle.)  Here's a close-up--notice the adults are winged, the immature bugs are not.:
So, about those seeds....most of them were demolished by the beetles, so maybe I'll have better luck next year....but it was a privilege to watch these "small wonders"--definitely way "off the beaten path!"  More in two weeks....


  1. Over the years I have had a problem with something laying eggs in seed pods. The larvae eat up the seeds in the pods, I mean completely leaving only dust. There is always a bore hole in the pod. I dont know if the hole is made to get in or out. Ive never seen the bug only the larvae, they are all white. When should I spray to kill the bug before it lays its eggs?

  2. Not sure! I know that hibiscus beetles enter the flower bud before the bud opens, so perhaps at the first sign of holes--but I have never tired it.