Nelson's Sparrow

Nelson's Sparrow

Tuesday, 19 September 2017

Three 'hids': Orchids, Syrphids and Aphids

Last week I had the occasion to show Ontario Parks staff the Nodding Pogonia (Triphora trianthophora) at Rondeau Provincial Park. Given the fairly recent change in Ontario Parks (OP) staff, none of them had ever seen the orchid. And given the orchid's official Endangered status, it was important for OP staff to see it first hand, and have a greater appreciation for the challenges in understanding and ultimately managing for this orchid. Many readers will know that it is a favourite species of mine. I have been observing the species annually for almost 45 years, including having study plots set up in one of the main areas for over 30 years.

This is what we hoped to see, although it is a little late in the season for it to be in its prime.
 We did see a few plants that had drooping flowers, indicating they were in bloom a day or two earlier. But since each flower only lasts for a single day, and all the ones that are ready to open up do so on the same day, the chances of seeing them in flower is limited. We did see plants that had bloomed earlier in the season progressing nicely and forming seed capsules so that is encouraging. A couple of years ago it was so dry that the few flowers that may have opened (and there was no concrete evidence that any did) did not produce any seed capsules at all, which is not good for a species that is endangered and with its entire known Canadian population limited to Rondeau!
Developing seed capsule

The survey of 2017 resulted in only 51 plants being counted, although there is at least one other location in the park which likely had a few individuals. However that location is even more remote, and seldom looked at.

While we were at the Triphora site, we came across some great examples of the Beech Blight Aphid, a.k.a. Boogie Woogie Aphid.



The latter name is due to its action when a branch is bumped or it otherwise feels threatened. They all make themselves a little bigger with their rear end stuck higher, waving a thread-like feature of their anatomy. Supposedly this collective behaviour might scare away any birds looking for a meal along the branches.

After leaving the Triphora site, I took the OP staff to the site of another orchid. It is Autumn Coralroot (Corallorhiza odontorhiza). It is tiny as well, although not endangered. This first photo shows what it might look like from a metre or so away.
 Obviously it doesn't stick out like a sore thumb, but when you get down on hands and knees and look closely, it is attractive. These next two photos show some relatively open flowers. This species is also known to self-pollinate, and sometimes the flowers don't open at all.

 Once pollinated, the flowers and developing seed capsules droop even more, before eventually becoming upright. The capsules will split open in several spots, allowing the extremely light seeds to be transported by even gentle breezes to a location potentially suitable for them.

I also took a bit of time on a recent visit to check out some of the goldenrod, where late season pollinating insects abound. There were the usual wasps and flies. On this occasion I was checking out the Syrphid flies, also known as hover flies or flower flies. The black and yellow patterns are attractive, and help identify them to species. Due to the great number of Syrphids, I posted some of the images on BugGuide, an on-line database designed for people across North America to post images and have them identified. In spite of some of the varied reference books I have at home, the number of insects one will come across is huge, and this on-line database is immensely useful. Here are three Syrphids species that I photographed, although when I initially photographed them, I thought there might have been more than three species. I was not aware of the different patterns between males and females of the species.
White-banded Flower Fly (Eristalis dimidiata) female

Erstaliis dimidiata male

Transverse Flower Fly (Eristalis transversa) female

Eristalis transversa male

Helophilus sp




2 comments:

  1. Saw those Boogie Woogie Aphids doing the boogie woogie once - absolutley wild!

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    1. Yes they are highly entertaining aren't they. It is always fun to come across a branch of these.

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