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...
Today is overcast and windy, and most insects are settled in for the day. When I went out to search for the bug of the week, I was lucky to find this large insect resting on our milkweed plant. Being cloudy with gusty winds, it wasn’t easy getting a photo that was in focus. Here’s my best shot.
Check out the beautiful orange colors on the wings and the spiny legs. If you don’t recognize it, this is a tarantula hawk wasp. Belonging to the family of wasps known as the spider wasps, the tarantula hawk female searches for large spiders. When she finds one, she stings it and then drags it to a burrow she has prepared. Inside the burrow, the wasp lays eggs on the spider. The spider is still alive, but paralyzed. Over time it becomes baby wasp lunch.
Now take a look a something else. Can you see the yellow bit hanging from one of its feet? It isn’t in focus, so it may not look like much.
Here is a photo of another tarantula hawk wasp I took last year. Maybe you can see the bright yellow bits on the tips of its front legs more clearly. They are in pairs, and curve sort of like tiny maple keys.
The tarantula hawk has a special relationship with the desert milkweed plant. Its slender legs fit into special grooves in the flower while it is drinking nectar. The grooves contain bundles of pollen called pollinia. The pollinia catch on the wasp’s legs. When the wasp flies to another milkweed plant, the pollen is transferred and the plant is pollinated.
If you look closely at this wasp you might be able to see the mud on its body where it has been digging its burrow, or perhaps from when it emerged from the burrow its mom built.
For some live action videos, go to You Tube and search for tarantula hawk wasp. In one video, tarantula hawk wasp vs. wolf spider, you can see a wasp trying to drag its spider back to its burrow. Now, that is quite a sight!