Pitcher plant vs. wasp: survival of the slipperiest

A European paper wasp (Polistes dominula) trying to feed on tiny droplets of nectar secreted on the underside of the operculum of a yellow pitcher plant (Sarracenia flava). The wasp has a very precarious hold on the slippery lip of the plant’s funnel shaped leaf, which forms an escape-proof trap containing digestive enzymes. You can tell that this isn’t going to end well…at least not for the wasp. The wasp was approximately 15 mm (0.6 in) long.

For several years I have been growing Sarracenia pitcher plants in a large pot in my back yard (my miniature bog garden). Sarracenia is a genus of carnivorous (insectivorous) plants that are native only to North America. The plant’s leaves grow the shape of a vertical or horizontal funnel with a flap-like cover over the opening (the operculum). The plants secrete nectar on the lip (the peristome) and underneath the operculum; and the lip and inner surface of the leaf are also slippery with a coating of wax.  Insects are attracted to the nectar, can’t find secure footing, and slip into the tube. The tubular leaf narrows significantly making it impossible for the insect to spread its wings (if it has them); and the inner lower surface of the leaf is covered with downward pointing hairs. The insect can’t fly or climb back out. The plant secretes enzymes to digest the hapless insect, and then absorbs the nutrients. Not a pleasant sounding death I must admit.

Yellow pitcher plant (Sarracenia flava). Note that an enterprising spider has built a web on the pitcher on the right.

These plants are quite effective at trapping insects. Occasionally I’ll cut open an old pitcher to take a look, and they will always be absolutely stuffed with bits of insect exoskeletons. However, despite growing these plants for years, I had never actually seen one trap an insect until last week. I just happened to be out in the garden with my camera and as I walked past the pot of Sarracenia a European paper wasp (Polistes dominula) landed on a specimen of S. flava (yellow pitcher plant). It promptly crawled under the operculum, clearly trying to feed on the nectar secreted there. I managed to quickly snap a couple of photos before the inevitable happened, and the wasp lost its footing and disappeared into the trap. It all happened very quickly—it’s no wonder I hadn’t witness it before.

And there it goes…a Europeanpape wasp (Polistes dominula) has lost its footing and is sliding down into the trap of a yellow pitcher plant (Sarracenia flava). The wasp will be digested to provide nutrients for the plant. Unfortunately I missed the focus on the wasp as it slipped to its doom…but the picture still tells the story.

To be honest it was a bit grim walking away from the plant, knowing what was about to happen to the wasp. But now whenever I’m trying to have dinner while being harassed by a bothersome wasp, I can’t help think that I wish it would go visit my pitcher plants…

Cheers,
EC

The technical stuff:
Camera: Olympus OM-D E-M5
Lens: Zuiko 60mm micro four thirds macro
Settings: manual exposure (F11 @ 1/200 sec)
Lighting: Olympus FL-36 flash (on TTL) (diffused)
ISO: 200

Flyday July 26, 2013: the fabulous flesh fly

A flesh fly (Sarcophaga sp.) cleaning itself after feasting for a while on a salmon carcass. Such gorgeous eyes…!

TGIF: Thank God its Flyday!

Is this not a gorgeous animal, what with its’ bright red eyes highlighted against a grey background? And the pinstriped thorax adds a dapper touch doesn’t it? It’s a flesh fly, Sarcophaga sp.

These are the flies that I was really thinking about when I instituted my Flyday series. I would really liked to have uploaded photos like these for my very first Flyday blog, but I didn’t have any images that I hadn’t already posted. I photographed this specimen on the same day that I shot last week’s Flyday subject (see Flyday July 19, 2013: the greenbottle, now that’s a fly!). Flesh flies, as you might have already surmised, are carrion flies: attracted to dead things on which to feed and/or deposit their maggots. Apparently flesh flies don’t lay eggs like most other flies. Flesh flies are ovoviviparous: the female retains the fertilized eggs inside the body until they are ready to hatch.

A flesh fly (Sarcophaga sp.) feeding on a salmon carcass.

I attracted this specimen (same as the greenbottle I featured last Flyday) by putting the remains of a sockeye salmon out on my deck. These flies aren’t too skittish (at least not when they are feasting on some fine BC sockeye), so photography was straightforward. The Zuiko 60mm macro lens I am using provided plenty of working distance. One nice thing about these flies is that they are not shiny. That plus their grey background colour makes lighting them easy.

Part of me wishes that flies like this were the size of canaries. Then people would better appreciate how attractive they are. They’d probably make good pets too. Just imagine a birdcage hanging in your kitchen, with your favourite flesh fly sitting on its perch buzzing contentedly.  It would be just like having a purring cat in your lap! Well, except for having to feed it dead things. And then there are the maggots….

Cheers,
EC

The technical stuff:
Camera: Olympus OM-D E-M5
Lens: Zuiko 60mm micro four thirds macro
Settings: manual exposure (F11 @ 1/200 sec)
Lighting: Olympus RF-11 ring flash (1/4 power)
ISO: 200

Peculiar hitchhikers

I just want to share this fascinating blog by Daniel Llavaneras. Very cool photos and a very cool story!

Cheers,
EC

They go "Crunch"

Phoresis has been well studied interaction in biology, and it has been reported in both vertebrates and invertebrates. An example of vertebrate phoresis is the remora (Perciformes: Echeneidae), whose first dorsal fin is modified into an oval sucker that allows it to attach itself to larger marine animals, and one example I’ve seen often in invertebrates is pseudoscorpions on beetles, particularly longhorns (Cerambycidae). But I recently learned that phoresis in invertebrates is a world about which I know nothing.

We collected some beetles in the Andes a few weeks ago. Nothing too eye-catching, just some scarabaeids that landed on the light trap. We collected a few and didn’t think much about them after that, so they stayed in a jar at the lab. I reviewed the contents of the jar earlier this week and saw something interesting: about 30-40 mites were floating around in the alcohol, and two beetles had…

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Flyday July 19, 2013: the greenbottle, now that’s a fly!

Greenbottle fly (Lucilia sericata) feeding on a sockeye salmon carcass

Its flyday! 

Greenbottles (Lucilia sericata) are easily my favourite fly. These critters are so gorgeous with their iridescent coppery-green bodies and red eyes set against a white face. And all those black hairs (setae) make them even more interesting. They are big (for a fly), bold and beautiful. The other species of flies I have featured on Flydays have been nice, but pale in comparison to greenbottles! 

Is it weird that I have a favourite fly? 

Greenbottles are blow flies—feeding and laying their eggs on dung and carrion. The handy thing about blow flies is that it is easy to get them to come to you to be photographed. I attracted this specimen (and a number of other species) by putting the remains of a sockeye salmon out on my deck. I’d filleted the fish for dinner and kept the skeleton specifically to attract some flies. It didn’t take long for hungry flies to start showing up. 

At one point, as I was photographing this greenbottle another smaller and less colourful species of fly (Musca sp. probably) wandered into the frame. I caught myself thinking “that’s not a fly” [shifting my attention back to the greenbottle] “now that’s a fly!” And that made me laugh out loud because it reminded me of the knife scene from the absurd 1986 movie Crocodile Dundee. There I was, on my back deck, laughing to myself while photographing flies attracted to a dead salmon. I sometimes wonder what my neighbours think about me… 

In case you aren’t familiar with the movie Crocodile Dundee, I’m including a bonus video clip below. I recommend pausing at 0.50 of the clip. 

And now back to greenbottles…here are a couple more photos of this beautiful fly. 

I don’t usually like pictures of critters that don’t show the eyes, but this is an exception. Even from behind greenbottle (Lucilia sericata) flies are pretty!

Greenbottle fly (Lucilia sericata) feeding on a sockeye salmon carcass: getting down underneath where the really good wet goo is!

Happy flyday!
EC 

The technical stuff:
Camera: Olympus OM-D E-M5
Lens: Zuiko 60mm micro four thirds macro
Settings: manual exposure (F11 @ 1/200 sec)
Lighting: Olympus RF-11 ring flash (1/4-1/2 power)
ISO: 200

Portrait of a Thai micro crab

Portrait of a Thai micro crab (Limnopilos naiyanetri) viewed slightly from above. This was a tiny animal, only 2 or 3 mm across the carapace. When full grown the carapace will only be 6-7 mm across.

I haven’t posted any interesting aquatic species for quite a while…I haven’t posted any uninteresting aquatic species for that matter. 

The pictures above and below are of a tiny specimen of a Thai micro crab (Limnopilos naiyanetri). This is a totally freshwater species of crab that have been found only in Thailand (so far). I discovered these little critters when I dropped by a local pet shop to buy crickets (to feed to my various mantids, scorpions and spiders). I hadn’t heard about or seen this species before, so I bought a couple to photograph and add to my aquarium. Mind you, even after I bought them I still hadn’t really seen one. Even with my reading glasses I couldn’t see them very well—which probably says as much about my eyes as it does about the crabs! But these things really are tiny: if one was to sit on my little finger nail its legs wouldn’t reach the edge. “Micro” is an appropriate description for these crabs. 

My aquarium is full of wood and plants, and I knew that once I added the crabs I would be lucky to ever see them again; so I took the time to take photos first. I used the same little aquarium and basically the same set-up as I described in this post: Photography of a diving beetle part 1. I used a clump of Java fern (Microsorum pteropus) for the photos: this species of plant is native to Southeast Asia, so the pictures are reasonably representative of the species in their native habitat. 

Portrait of a Thai micro crab (Limnopilos naiyanetri). Apparently the thread-like setae on their chelipeds (pinchers) are used to filter food particles from the water.

Thai micro crab (Limnopilos naiyanetri) lurking amongst fronds of Java fern (Microsorum pteropus).

Once I’d finished photographing the crab I tried taking some video. It turned out pretty well, although if you check it out (below) you will see that the depth of field was very shallow. I didn’t have very much light and had to shoot with the lens wide open. Only later did I realize that I should have increased the ISO so that I could have used a smaller aperture (and gained depth of field) (insert head slapping sound). I am so used to always shooting with the smallest ISO possible that I just didn’t think of it! Oh well, my video technique can only get better. I hope… 

Cheers,
EC

The technical stuff:
Camera: Olympus OM-D E-M5
Lens: Zuiko 35mm macro
Settings: Series 1: manual exposure (F11 @ 1/200 sec)
Lighting: Olympus RF-11 ring flash (1/4-1/2 power)
ISO: 200

Flyday July 12, 2013: a fresh new mosquito

Mosquito photographed (in Delta, BC, Canada) just after it had emerged from its aquatic pupa and was standing on the water surface readying itself to fly away

Its flyday! 

Many people don’t realize that mosquitoes are a type of fly.  I photographed this nice specimen just after it had emerged from its aquatic pupa and was standing on the water surface readying itself to fly away. It’s amazing how pretty this little beast was when you see it up close, what with its sparkly green eyes! It would probably be even prettier if it had a gut full of red blood too! Hmmm…green eyes and red blood…that gives me an idea of what to post next Christmas!  

Portrait of a mosquito photographed (in Delta, BC, Canada) just after it had emerged from its aquatic pupa and was standing on the water surface readying itself to fly away

This mosquito was a product of my backyard swamp: an old half wine barrel full of mud topped with a few inches of water (and planted with a thick mass of emergent water plants). This was also the source of a number of nice mosquito larvae and pupae that I also photographed. Those photos will be the subject of another post in the near future. 

And no, biting mosquitoes aren’t a problem in my garden. The many spiders, damsel flies and other insect predators (not to mention my carnivorous plants) seem to be more than a match for the relatively small number of mosquitoes that emerge from my “swamp”. In fact I haven’t had a single mosquito bite so far this summer! 

Cheers,
EC 

The technical stuff:
Camera: Olympus OM-D E-M5
Lens: Zuiko 35mm macro
Settings: manual exposure (F11 @ 1/200 sec)
Lighting: Olympus FL-36 flash (on TTL)
ISO: 200

Jumping spiders update: oops!

Mea Culpa

There is a quote circulating on Facebook  that basically says that you are doing science wrong if you don’t make mistakes; that you are doing science REALLY wrong if you don’t correct those mistakes; and you AREN’T DOING SCIENCE at all if you don’t accept that you’re mistaken.

Well, in the past week I have posted twice about photographing jumping spiders that were prowling around on my kitchen screen door hunting for insects (see part 1; and part 2). In my posts I identified the spiders as zebra jumping spiders (Salticus scenicus). However, I noted that the two specimens I photographed had different markings and suggested that the darker spider might have been a male.

Nope, I was wrong. It turns out that the darker spider is a different species: Platycryptus (probably P. californicus). It also turns out that what I thought were mosquitoes were actually non-biting midges (chironomids). Sigh.

I have re-edited both posts and corrected these mistakes. Many thanks to Ciphor on the arachnoboards forum for helping with the spider identification; and to John Carr on the dipteral.info forum for correcting my misidentification of the midges.

I must be doing GREAT science!

Cheers,

EC