Spider Catches Butterfly

Buckeyes are currently the most common large butterfly species at Blue Jay Barrens. Swallowtails and Fritillaries, usually very common during the summer, have been almost nonexistent this year. I’m thinking that the never ending spring rains may have been partially responsible for this absence. Buckeyes, being migrants that move into the area from the south each summer, would have avoided any local springtime catastrophe. As a species they have thrived, but this individual met with disaster in the form of a crab spider.

It’s not unusual to see butterflies being held by crab spiders. This was a special event, because I was able to witness the action of the capture. The spider was hiding in the flowers and grabbed the butterfly when it stopped to nectar. The butterfly initially seemed stunned. A second later it suddenly took wing and pulled the spider from its perch. The spider held tight and played out line in the form of spider silk to cushion the jerking struggle of the butterfly. The event looked much like a fisherman playing a huge marlin. The pair spun circles and zipped back and forth for many seconds.

Even if it had broken free, the butterfly was finished. Upon initial capture, the spider’s first act was to inject the butterfly with paralyzing venom. After a short but violent struggle, the butterfly was subdued.

With its prey secured, the spider began to reel in line.

Once back to the flower, the spider let the line go free. It then began to arrange its prey for consumption.

The spider’s final act before settling down to feed was to conceal its body in the flower cluster. A capture like this is a common event in the prairie, but it’s not one that you very often get to witness from start to finish.

Common Milkweed Creatures

I began the week with a look at various animals on one type of milkweed, so I thought it appropriate to finish the week with a look at creatures inhabiting another type of milkweed. Common Milkweed is widespread, but it seems to prefer soils towards the moderate to wet end of the moisture scale. The flowers usually don’t form the dense cluster typical of other milkweed species and their tendency to droop detracts from the visual effect. It’s still a powerful attractor of insects and other small creatures.

Continuing with the black and orange theme of milkweed dependent insects is a pair of Milkweed Beetles.

It seemed to be a time of interaction for the creatures of the milkweed plant. These Milkweed Beetles are doing their best to ensure a future supply of beetles. In fact, I didn’t find any single beetles on any of the plants I visited.

Ambush Bugs were also busy starting a new generation. Mating insects are a little slower to move to cover when disturbed, so make good photographic subjects.

The flower clusters were full of small beetles and showed many signs of feeding damage.

Where ever insects congregate, you’ll find predators. That’s certainly an impressive set of spiny legs. I wonder if the spines serve as some sort of sensory device.

There was also a lot of interaction between different species. The beetle fled a flower cluster as I was pushing the plant around to get a good picture. The spider was quick to take advantage of the opportunity.

I’ve pretty much learned what to expect when I see a butterfly acting strangely on a flower. Edwards’ Hairstreaks move about almost constantly when nectaring. If you see one holding still, you know there’s something wrong.

Just as I suspected, a crab spider. This sort of activity goes on all the time, but I hate to see the rare things being killed. I hope it took care of mating and egg laying before it came over and got itself eaten.

Round Podded St. Johnswort

Last week I mentioned the non-native Common St. Johnswort . There are also some natives like this Round-podded St. Johnswort, Hypericum sphaerocarpum, a short growing plant with a vibrant lemon-lime colored bloom. I’m always happy to see this plant.

No dark spots mark these velvety petals. The mass of long stamens tend to stay bunched together until the time of peak pollen set and then they spread out to create an illusion of softness. Spread stamens seem to signal insects that this flower is ready for visitation. I call this little bee a Calf Pincher, because this type always gets on the backs of my legs when I wear shorts and gives me a little pinchy sting when I crouch down.

Once the flower is fertilized, the stamens tend to close back together. The old petals persist for quite a long time after pollination. Their shriveled remains are often still present when the seed filled pod reaches its full size. The sharply pointed bracts seem to stand as a guard around the developing bloom.

Dangling from beneath a flower is not a normal position for a bee. So what could be holding that bee in place?

I was guessing Ambush Bug, but instead, I found this nice chunky crab spider. Many species of crab spiders ambush prey that has come to feed at a flower.

Small bees are probably the most common prey for these spiders. Later in the summer, it often appears that the majority of flowers have crab spiders stalking their petals. It’s the high numbers of flower visitors that makes it at all safe for small insects to search for nectar and pollen. The spiders can only eat so much each day, so the loss of a couple of insects makes it safe for the majority of visitors.

Moth and Spiders

I was looking for spiders on some Orange Coneflowers growing outside my barn when I spotted this moth. At first glance it looked more like a wasp than a moth. This is the Eupatorium Borer Moth, Carmenta bassiformis, which uses the Ironweed as a host plant. The moth larvae feed on the roots and the inside of the stem. Maybe this is what the Downy Woodpeckers have been searching for in the Ironweed stalks.

The moth was taking quite a risk nectaring on these particular flowers. On the next flower over was this attractive Crab Spider. Quite hard to see against the dark yellow of the flower. Here it will perch until a likely insect happens by. Then those long legs will reach out and grab the prey.

This is the view an approaching insect would get. Nothing menacing here.

On the next flower is this handsome fellow with attractive maroon markings.

It just looks like part of the flower from this angle.

A smaller specimen. I don’t think this little guy would have been a threat to the moth.

A second small spider waits for a meal. Out of twelve flowers, four were inhabited by spiders. That makes the odds one in three that a feeding insect could be landing on the dinner table. Flowers like this seem to be favorites of the yellow Crab Spiders. I don’t think I’ve checked any group of these flowers and not found some spiders.