Thursday, September 8, 2011

More fascinating insects!

There is definitely a smell of fall in the air, a spiciness, leaves are turning colours, the daylight hours are shorter and the nights are cooler. I always feel a little sad to see the end of summer, migrants leaving and songbird voices quiet. Sunsets are spectacular right now, something about the light gives more saturation to the red and pink hues.

I have a cast on my foot so have been doing a lot of sitting outside and it’s stunning to see the diversity of insects flying around, and in particular wasps; small parasitic wasps, those that hover, striped, plain, large, and even some bright green ones. Yes, they are at times annoying when food is around but if you ignore them or stay calm and gently shoo them away they are not aggressive and leave. Don’t panic and flail or swat or squeeze them as they might sting in self-defense, and you can’t blame them for that. I have never been stung and we have several species nesting near our deck. Insects are part of the web of life, we need them but they don’t need us, remember this.

Organ-pipe Mud Dauber nest

Some wasps are particularly nice to have around, take for instance the Organ-Pipe Mud Dauber Trypoxylon politum that has built a lovely nest on the cedar shake wall at the back of our house, near the roof, sheltered from the rain. It’s an architectural gem, really looking like organ pipes. I marvel at the design and the many trips carrying bits of mud the wasps must have taken to build it.  These wasps are large and black, are very docile and are not known to sting humans and best of all their main food source is spiders, which we have plenty of. I am pleased to have them living near us and helping keep our spider population in check.

  The Black Swallowtail caterpillars on my parsley survived to the last instar and then moved out to find a place to pupate. I have yet to find the pupae. 
Black Swallowtail last instar

Milkweed Tiger Moth

Yesterday I discovered 15 very pretty tufted moths on Common Milkweed plants in the front flower garden.


They are the larvae of the Milkweed Tiger Moth Euchaetes egle. They feed on Milkweed and Dogbane plants and like the Monarch Butterfly, the toxic chemicals from the milkweed are retained in the adult body. However instead of a visual warning of their unpalatability which would not be useful at night, the moths emit a click to deter bats from feeding on them. So much complexity!

Another exciting discovery was that of a large moth that looked like a piece of bark. I noticed it on the brick wall, it must have been disturbed from a hiding spot to end up in the open in the daytime. After some research, it was determined to be a nocturnal Bride Underwing Moth, Catopala neogama. The underwings were not showing but they would be a bright orange-red colour with black stripes. The moth was at least 2.5 inches long and 1.5 inches across and very convincingly looked like a piece of bark from a distance. The larvae feed at night on the leaves of Walnut or Hickory or Butternut and occasionally Oak tree species. We have a large Black Walnut tree near the house so perhaps it was the host tree. This morning the moth was gone, so I am lucky to have seen it.
If you are observant and curious, you will likely come across all sorts of interesting life forms and learn something new.

1 comment:

  1. I love your caterpillar photos! Although, I do think that the insects need us too. Humans are also part of the web of life and it is our arrogance in believing that we are not part of that web that drives the destruction of the planet that sustains us. We are overall having a negative effect on the planet and all of its inhabitants (including ourselves!) but we cannot overlook the positive influences we do have on other species. For example the wasp nest under the cedar shakes on your house...they may not have found a spot to build their hive otherwise...