Edit: this post has been moved to my new ant blog, Wild About Ants.
Sometimes adding a new plant to your yard can unexpectedly bring in exciting new animals. When our recently-planted potato bush began to flower, we started to hear a novel sound from its vicinity. The bush seemed to be bizzing. Bizz, bizz, bizz.
Upon investigation, the sound turned out to be these striped bees, a species of digger bees. The potato bush has deep purple flowers which produce only powdery pollen, not nectar. The center of the flower is a yellow knob. The bees fly into the center, grasp the knob, press their abdomen against it, and then bizz. The vibration produced causes to knob to release pollen like a salt shaker releases salt. The pollen sticks to the fuzzy body of the bee as the bee flies on to the next flower.
What do the bees do with the pollen? They groom it from their bodies, form it into clumps, and mix it with nectar to feed to their larvae. When bees make a noise to release pollen from a flower it is called buzz pollination.
When carpenter bees visit the plant, they make a deeper buzzing tone, as you would expect with their larger bodies.
Tomato flowers are similar in structure to our potato bush. When people grow tomatoes in greenhouses, they may actually bring in bumblebees to perform the task of buzz pollinating their crops. For more information, visit the GEARs website. (link broken)
Upon revisiting the same plants again and again while searching for the bug of the week, I've made an interesting discovery. Although we think of insects as being highly mobile, a few do settle down for a period of time and make a plant their home. For example, the tarantula hawk from last week is still around. It seems to be a male and it has staked out one of our milkweed plants as his very own. We've started calling him our "pet" tarantula hawk wasp.
Going back to where I found the assassin bug earlier, I was surprised to find this adult assassin bug. The adult looks very different from the bright orange nymph. It is green with dark red on its wings. Would you have recognized it? I wonder if it the same one...