Wednesday, August 17, 2016

One Night To Shine!

3D anaglyph image!
3D anaglyph image!
Since July and August weather doesn't agree with astronomy (it is our monsoon season, threatening rain most days), one of my favorite activities is chasing the blooms, flowers and pollinators of the array of Cereus repandus cacti we've got growing on the east side of our house. Clicking the above link will take you to some of our earlier posts of these amazing flowers. If the 15cm (6"!) diameter, night-blooming flowers aren't enough to keep your interest, the specialty pollinators that come out at night to feed are amazing too! These top two images here are recent bloomers, shown here as anaglyphs - get out your red/blue glasses to see them in 3D stereo! The right image is unusual - normally as soon as the sun hits them they are on their way to closing - I've got a time-lapse of that!



Days to blooming!
For my one-eyed readers, or those of you who don't have any anaglyph glasses, you can enjoy this image at left. There are usually a pair of blooming seasons per summer - the first one in May with a few blossoms, but the real blooming session appears to be in late July and August, at least in my yard with my variety. We missed the first blooming season when we were in Illinois for a couple weeks, and the latter season was while Melinda was taking the tour of health facilities around Tucson... Fortunately, I would come home late each night to do cat chores, so usually came upon the flowers already open. Interestingly this second season, the flowers either seemed to be 7 or 8 feet off the ground, or down a foot off the dirt, so would either have to get out stepstool and the tall tripod, or lie down on the ground. Fortunately, there was one blossom at the perfect 4 foot (1.2 meter) level that I waited to bloom. Also, once the flower bud was first spotted - a little nub less than 5mm (1/4") across, I started regularly imaging it until it bloomed, as shown at right...


So from the afternoon shot taken earlier in the day, I knew this bloom would blossom that night. I didn't get home till well after 1130, and sure enough it was already wide open and I arranged my camera (Canon XSi - 'cause of the on-camera flash, macro and  about 5cm of extension tubes). Focusing quickly on the center green stigma of the flower - I could see that the pollinating moths had already visited. How could I tell? Well the Stigma was already covered with pollen and some of the hairs and "feathers" of the rustic sphinx moths that normally visited. Look at the image at left, and the same image at full camera resolution at right. While the anthers are still relatively loaded with pollen, with the stigma loaded up (they must be sticky to hold on to pollen and moth hairs) you can see it had been visited the previous 90 minutes the flower had likely been open.

So what does it look like before the moths visit? Glad you asked as a few days earlier I caught one just as it opened before 11pm. Shown at left you can see the stigma is a clean green with anthers fully loaded with pollen just waiting for a passing moth to brush some across it. By early in the morning, I went out to shoot a corresponding macro shot of the stigma after a long night of visiting pollinators. Shown at right is the above flower at 5am. Compared to the images in the preceding paragraph, it looks absolutely furry from moth hairs, and the anthers are pretty much denuded of pollen...



So who did we attract as pollinators this time? Between about midnight to 5am I took pictures every 20 seconds, hoping to accidently capture some pollinators. The 830 frames show exactly 4 visits by rustic sphinx moths, though you will see that one likely visited twice making only 3 moths visiting overnight (also not counting the moths arriving before midnight. In the images at left and right, each of these moths stayed for 2 exposures taken at 20 second intervals, so about a half minute. This is the moth pair I'm thinking is a second visit by the same moth. Only 7 minutes between visits, you can also spot a pair of gaps in it's left wing, more visible in the left hand image of each.



Here at left is the first moth visit recorded after midnight - 1236 by my camera clock. Note that the wing edges are very clean and the colors pretty bright - likely indicating a young moth. Then after the same moth visit from the preceding paragraph, at right is the last one, coming by at 3am for a visit. Even though much of the image is out-of-focus, you can see the left wing has some sizeable chunks out of it - indicating an older specimen perhaps, and certainly making identification easier had it made more visits... Unfortunately, there are no more buds indicating any flowers coming up, so the blooming season might be over...

Still these are always interesting to observe - the proboscis longer than the body allows feeding on nectar far down the throat of the flower. Had I time to stay up and monitor the camera/flower, I could have manually taken many more of the moth visits, though usually depend on the intervalometer to take frames at regular intervals. The moths don't seem too upset by the flash - last year managed 6 frames of the same moth over its 33 second visit.  Also interesting this blooming session was the complete lack of honeybees.  In times past the last few hours of the predawn hours were swarmed with bees, but not one to be spotted this time...

So after the flower blooms? After closing early in the morning after it blooms, it shrivels and dries out. At left is an image a day later, then again 3 days after the blooming. Note on the bottom image there is a little crack on the stem near the base. By just touching it, I managed to break off the flower, leaving the stem behind. Most of the flowers do that after blooming, the stump remaining turns into a fruit. After the flower broke off at right, the stigma hangs out by its long stem. Slicing the flower lengthwise shows the remaining flower parts, including the anthers, filament threads and flower petals...

As I said, you've got to make your own fun during the monsoon nights while you can't be observing. Fortunately these sorts of things are available to distract me from the cloudy skies!

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