The early bee and the flower, continued

Though a few bees collected nectar from the peony buds, the flowers had much more to offer once they were fully open.  In addition to nectar, the flowers produced large quantities of pollen, which was a big attraction to visitors such as the leafcutter bee (Megachile sp.) pictured below.  Unlike bumble bees and honey bees, which pack pollen onto their hind legs, this leafcutter bee is collecting pollen on the underside of its abdomen.

Pollen was not the only thing waiting inside the flowers, however.  One of the peonies contained an unpleasant surprise that threatened to make any visiting bee permanently late.

A crab spider (Misumena vatia) ready to ambush visitors to the peony.

Happy Fourth (Crab Spider)!

Happy Fourth of July!  To celebrate the date, here is a picture with four crab spiders, including one happy spider with a fly.

Can you find all four crab spiders?

In case you had any trouble spotting all the spiders, here is the picture again, with the spider locations marked...

Three female and one male Misumena vatia crab spiders.

 ... and here is a closeup of the happy spider with her large meal.

The most successful of the four spiders, eating a fly.

Congratulations, you survived! (A Father's Day sentiment)

For crab spiders, becoming a father is a perilous endeavor that involves a lengthy search culminating in a cautious approach to an uncertain ending. While on a walk this Father's Day, I spotted a would-be father that had been insufficiently cautious.

A female Mecaphesa sp. crab spider eating a male.

Whether or not that male crab spider had succeeded in becoming a father, it had succeeded in becoming a meal and was indirectly nourishing a new generation of crab spiders.

A spiderling on another flower.

So, even if human fatherhood has its trials, be glad you aren't a crab spider.

The lion's share of the aphid

A few weeks ago, while I was on a trip to Arizona, I took a walk in the desert.  (I did not make much progress as far as walking was concerned, though.)  There were many flowers blooming along the sides of the trail, so I zigzagged  from one flower to the next, checking for crab spiders or any other visitors (but really hoping for crab spiders). 

Brittlebush (Encelia farinosa) flowers and one of the several crab spiders that I found.

It was not long before my diligence was rewarded by my discovery of a very small crab spider.  After that, I checked each flower even more intensely and in the end found several small crab spiders, some with even smaller prey. 

A juvenile crap spider (Mecaphesa sp.) eating what looks like a thrips.

For example, the spider above is eating a tiny insect that appears to be a thrips.  Meanwhile, the remains of another crab spider's meal can be seen in the bottom left corner of the picture below (it is probably a tiny fly or bee).

This crab spider had already finished its meal (if you look closely, you can see what was left of it).

In my search for the spiders, I also encountered quite a few other visitors to the flowers, including another successful predator.  This predator was a lacewing larva that I caught in the act of living up to its name 'aphid lion'.

A lacewing larva, a.k.a. an aphid lion, with a captured aphid.

More than a pain in the neck, continued

After noticing the pattern in how candy stripe spiders tackle their prey, I decided to look back at my many pictures of crab spiders for comparison.  As I had thought, the crab spiders also frequently bit their prey just behind the head.

A female Misumena vatia crab spider eating a tricolored bumble bee (Bombus ternarius) in 2012.

The crab spiders took a different approach, however, when their prey was a hover fly (Syrphidae). 

A juvenile crab spider eating a hover fly (Syrphidae) in 2012.

In these cases, as illustrated in the pictures above and below, the crab spider bit right into its victim's abdomen.

Another crab spider eating a hover fly, this time on a snapdragon.

In addition to having a soft abdomen, hover flies are relatively easy for crab spiders to catch.  One way for hover flies to compensate for their vulnerability is to spend more time inspecting landing sites for potential danger; indeed, hover flies can often be seen seemingly suspended in the air above flowers before touching down to feed or darting quickly away.

Two hover flies inspecting a flower before landing.

Unafraid to be yellow

Most of the crab spiders that I find are white.  Not only do I find white crab spiders on white flowers, I also find them on pink, purple, red and blue flowers.  The exception is on yellow flowers, where the crab spiders tend to be a matching yellow.  Therefore, when I found a white crab spider hunting on the very yellow flowers of a goldenrod, I decided to keep track of it for the next few days.

Day 1: A white crab spider on yellow goldenrod flowers.

On the first day that I observed it, the white crab spider was doing quite well for itself despite not matching the color of the flowers.  It had caught a large fly, thus procuring for itself a substantial meal.

Day 3: The spider is pale yellow.

Notwithstanding its previous success as a white spider on a yellow flower, the spider had soon acquired a pale yellow hue.  After another two days, the crab spider had acquired both more yellow and another fly.

Day 5: The spider has caught another fly.

How had the crab spider turned yellow?  The color change was first triggered by the crab spider seeing yellow around it.  In response, the crab spider began to synthesize yellow pigments which it then kept in cells near the surface of its body.  (To return to white, the crab spider could move the yellow pigments away from the surface to be stored until needed again.)

Day 6: The spider is the same bright yellow as the golden rod flowers.

Why had the crab spider turned yellow?  Although the answer seems simple -- to hide from potential prey and predators -- studies of crab spiders have failed to find a benefit from either increased prey capture or decreased capture by predators.  Nevertheless, the metabolic cost of synthesizing the yellow pigments suggests that a benefit must exist (or at least one must have existed until relatively recently).

Keeping the enemy closer

While I was out for a walk, I came across a spider that was even more notable for abstaining from eating flies than the jumping spiders on the roses had been.  This spider had flies walking all over it, yet it made no move to catch them.

Flies sitting on a crab spider as it waits in ambush.

The flies were not in blind spots (crab spiders have eyes facing forwards, sideways and backwards); nevertheless, they may have been in the safest spot around.  Though the flies were tantalizing close, the spider may not have been able to reach around to grab them.  Another possibility could have been that the spider was simply waiting for larger or more appetizing prey to come along.

A bigger prey is a better prey?

However, as I was quickly being left behind by the rest of my group, after watching for only a little while longer, I left the spider to its hunting and the flies to their death defying stunts.

A farewell to spiders

Although I was excited to find so many crab spiders in the backyard upon my return from Europe, I knew that I would not have the opportunity to observe them for very long.  As soon as I had unpacked my luggage, it was time to start packing again -- only this time, everything was going into a moving trailer headed for Texas.  Therefore, I filled many of my breaks from packing with surveys of the garden, which turned up tiny crab spiders...

A very small crab spider on an aster

...camouflaged crab spiders...

A juvenile crab spider on a shrubby cinquefoil (Dasiphora fruticosa) flower.

 ...and hidden crab spiders...

A crab spider concealed in a daisy inflorescence.

 ...as well as the more obvious ones.

A female Misumena vatia spider sitting on a cornflower (Centaurea sp.).

Just as it seemed that packing would never end, the trailer was gone, my car was loaded for my drive down to Texas, and it was time to leave the spiders behind.

A warm welcome

Last week, I returned to Washington after four months of travels.  Of all the many things there were to do after getting home, one task near the top of my list was to search the garden for crab spiders.  Before leaving Washington in March, I had found just one crab spider in the yard.  How many were there now?  It took just a couple of minutes for me to locate the first crab spider, and then in quick succession I found several more, including this one: 

A juvenile crab spider on a daisy.

After bringing the tally up to six crab spiders, it was time for me to retreat out of the ~95°F heat and to turn to more mundane tasks.  However, the next morning, I took advantage of my jetlag and was out in the garden very early, while it was still cool.  During this second and more thorough search, I found ten more crab spiders.

A female Misumena vatia crab spider ready for some prey.

A couple of these I found not on flowers, but on foliage.  These spiders were either in transit between flowers or had opted for less conventional hunting sites.

A juvenile crab spider sitting at the tip of a rose stem.

Game over

Sometimes, it is the flower that gets bitten by the visitor.  Other times, it is the visitor that gets bitten.

A small crab spider eats a fly on a wood anemone (Anemone nemorosa) flower.

After searching hundreds of flowers, I was excited not only to see my first crab spider in Germany, but also to find it complete with prey.  However, since I realize that not everyone feels that a spider improves a flower, here is a view of some of those that were spider-free.

A patch of wood anemones (Anemone nemorosa) where just a few days ago I had only seen dry leaves.

The perfect goodbye present

Yesterday, I surveyed my garden in Washington for the last time before I depart for several months on a series of trips.  Although the snow was gone, it was still cold and there were hardly any more signs of spring than there had been a month ago.  As I looked over the wintry vegetation, I felt sorry that I was going to miss all of the spring -- and especially the progress of the new generation of crab spiders.  Then, just as I was nearing the end of my circuit around the garden, I saw a cluster of snowdrops (Galanthus sp.) poking up between the cotoneaster branches.

The first flowers to bloom in the garden: snowdrops (Galanthus sp.).

So, I had stayed long enough to see the first flowers of the year after all!  However, these flowers were merely the pretty packaging of my real present.  When I knelt down to photograph the fourth and last of the flowers, I saw that it was occupied by something with long, spindly legs.

Something is inside the flower!

I recognized the legs at once as belonging to a crab spider, yet I could not quite believe my luck.  Since my camera did not fit underneath the flower, I cautiously rotated the flower up.  Meanwhile, the spider emerged from its hiding spot and sat photogenically on the outside of the flower.

A very small crab spider on a snowdrop flower.

Though I am still sorry not to be able to chronicle the development of this crab spider and the rest of the garden population, I now feel like I am leaving the garden on a high note -- and, as I travel, there will be other gardens with new encounters to be had!

Earning their stripes

Just over a month ago, I found the garden crawling with tiny, white spiderlings.  Since then, I have been observing their progress intently.  Many of the crab spiders have captured enough prey to increase several times in size (for example, compare the spider in this picture to the one below).

A juvenile crab spider waits for its next meal.

Others have changed in appearance, as well as in size.  These spiders now sport dark stripes on the head, abdomen, and forelimbs; they may be juvenile males approaching their adult coloration.

A juvenile crab spider (Thomisidae), most likely a male Misumena vatia.

One thing that hasn't changed is that there are still crab spiders nearly everywhere I look.  They are on plant stalks, leaves, seed pods, and - of course - flowers.  However, space on flowers is limited.  Crab spiders attempting to take up residence on a new flower may find themselves too close to a hungry neighbor.

Two crab spiders face off on a flower.

The seed defenders

Many seed predators have converged upon the hollyhocks and are feasting on the seeds.  Nevertheless, things may not be as bad as they first appear for this new generation of hollyhocks -- for the seed predators have been attracting enemies of their own.  During my rounds through the garden, I have noticed that the hollyhock seed pods are also routinely patrolled by a number of predators.  The most common of these predators are wasps and ladybugs.

A European paper wasp (Polistes dominula) on a hollyhock seed pod.

A ladybird beetle (Coccinellidae) inside a hollyhock seed pod.

Although many of the hollyhock seed predators that I have seen are bugs, not all of the bugs on hollyhocks are necessarily there to eat seeds.  When I first saw the bug pictured below, I thought it was piercing through the pod to reach the seeds inside.

A bug eating a much smaller insect, speared on its mouthparts.

Upon close inspection, however, a very small insect is visible at the end of the bug's mouthparts.  In contrast, the bug pictured below was no longer a predator of any kind.  Instead, it had become the prey of a crab spider.

A crab spider (Mecaphesa sp.) eating a bug on a hollyhock seed pod.

Insects beware: here be spiders

My backyard has been looking very dry and brown from the summer heat.  Not hoping for much, I went out in search of life.  A few plants are still blooming and I was very pleased to see a small crab spider on one of the first flowers I checked. 

A crab spider and ladybug on a common hollyhock (Alcea rosea) flower.

Then there was another... and another.  On the bush pictured below, I found a tiny crab spider on almost every flower!

A tiny crab spider sits between the two petals on the right side of the flower.

I watched in suspense as a small bee visited one of these flowers.  However, just as for a previously featured crab spider, the little crab spider on this flower posed no threat for the bee.  The real danger for the bee came immediately after it left the flower -- and flew straight into a funnel-web.

A funnel-web spider eating a small bee.

The funnel-web spider, responding to the motion of the web, sprang up at the bee -- but missed.  The bee managed to force its way through the web and then sat on a nearby leaf for a few moments, grooming off the bits of web that had come with it. (The bee being eaten by the funnel-web spider in the photograph was an earlier catch.)

I then decided to check the front yard.  There it was the same: spiderlings everywhere. 

A tiny crab spider sitting on an aster and eating something even smaller.

The little one pictured above had found something even smaller to eat.  It won't be very long, though, before some of the dozens of young crab spiders have grown large enough to hunt bees.

The curse of the mummy

This weekend, to explore a bit further afield, I visited a public garden.  While the other visitors were admiring the densely packed flower beds and jotting down the names of plants, I was inspecting the undersides of leaves.  Leaves might not seem to have much to offer when compared to the brilliant colors of flowers and the fast-paced action of the insects that visit them.  However, the plainness of leaves disguises a world of quiet intrigue.

Often, the view from above provides a sign of the action underneath.  Chewed leaf edges are a clue that there may still be a hungry caterpillar below.

A furry caterpillar munches on a leaf.

Meanwhile, folded leaves can shelter a nest.

A female Misumena vatia guards her nest.

Even the leaves that look normal from above may hide a surprising secret.  As the people around me were busy identifying new plants to add to their own gardens, I discovered a mummy. 
 

A mummified caterpillar.

This caterpillar had been mummified by a parasite (likely a wasp).  The developing parasite would have fed on the caterpillar from inside before breaking out of the mummy through the hole that is visible at the top.