Tuesday, April 30, 2013

Death among the bleeding hearts

With the - long awaited - return of warmer weather the insects are coming back.  Which means I can do a little more macro work in the garden.

One returnee is this little hoverfly.  I'm not sure of the species - the small ones are notoriously difficult - but it's common throughout the warmer months.  Only about 8mm long. I needed a 25mm extension tube on my Tamron 90mm macro to half fill the frame with this shot of it feeding on the pollen of Ranunculus ficaria, a pretty little spring flower (ok, weed) in the front garden.

Small hoverfly on Ranunculus ficaria
But with prey, there come predators.  Walking in the garden this lunchtime I noticed the pale body of a crab spider, Misumena vatia, on my emerging flowers of bleeding heart, Dicentra spectabilis.  Closer inspection revealed that it had captured one of these small hoverflies.  Typically for an ambush predator, the spider would have waited patiently on the flower to await a suitable small nectar or pollen feeder and then pounced.

Out came the 180mm Sigma macro on the tripod to give me enough working distance to avoid disturbing the spider and its prey.  No flash for these shots - it was a bright, sunny day, though I did use a small reflector.
Misumena vatia predation on a small hoverfly
However, even 1:1 wasn't close enough to get a frame filling shot.  Rather than relying on cropping I added my 25mm extension tube to provide a little extra magnification. 

Misumena vatia predation on a small hoverfly.  180mm macro + 25mm extension tube.
Once the prey is captured and poison injected through the front palps the spider needs to hang onto the prey for long enough for the flesh to liquify and being absorbable.  Which means it will hang on to and even carry the prey around.  More shot opportunities as the spider manouvered among the flowers of the bleeding heart.
Misumena vatia predation on a small hoverfly

Misumena vatia predation on a small hoverfly
At this time of year the spider is small.  It will grow grow during the year and is then capable of taking larger insects.  I've seen them take small butterflies so the larger hoverflies and similarly sized pollen and nectar gatherers are no problem at all.  Feeding on the flowers has its risks.

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