Photo of the Week – September 16, 2011

Sometimes I’m amazed that there are any pollinators left in the world.  Not only do they have to survive habitat loss, habitat fragmentation, herbicides/pesticides, introduced diseases, and competition from introduced pollinators like European honey bees, pollinators also have to deal with all the various predators that wait in ambush on flowers!  Imagine making your way through a deadly obstacle course all day long, finally arriving home, opening the refrigerator to grab some dinner, and getting eaten by a troll hiding inside.

In December of last year, I wrote about crab spiders and their tactics for capturing visitors to flowers.  The photo below is of an ambush bug that uses eerily similar tactics.  You know, just to keep those bees on their toes.

Ambush bug (Phymata sp.) on stiff sunflower (Helianthus pauciflorus). Beatrice, Nebraska.

Ambush bugs are closely related to assassin bugs, but have thicker bodies and legs.  They are well camouflaged and sit on flowers, waiting for something to get close enough to grab.  Once they have prey in their mantis-like front pincer legs, they (like crab spiders and assassin bugs) inject the with paralyzing and liquefying saliva and then suck the insides right out of the poor visitor.  I find it fascinating that two creatures as distantly related as crab spiders and ambush bugs have such similar hunting and feeding techniques.  Assassin bugs and ambush bugs both use piercing mouthparts to inject their saliva and suck out the bug innards, while crab spiders have fangs.  Otherwise, the story works about the same way.  I doubt the prey have a preference one way or the other…

This particular ambush bug was sitting on a stiff sunflower in a prairie planting on the campus of Southeast Community College in Beatrice, Nebraska a couple weeks ago.  It sat very still for the 5 minutes or so it took to get these photos.  The challenge wasn’t to get the insect to stop moving – it was to wait for the tall flower to stop swaying in the breeze!

For more information on ambush and assassin bugs, you might be interested to read this article from the Missouri Conservationist.

Photo of the Week – September 9, 2011

This week our Platte River Prairies are in full autumn regalia.  Everywhere you look, big yellow composite flowers, especially sunflowers and goldenrods, dominate the visual landscape.  At least 15 different species of yellow flowers are blooming right now.  They are set against the golds and purples of the warm-season grasses, which are also in full bloom. 

Maximilian sunflowers have just started to bloom, joining a crowded field of five other sunflower species in our prairies. (Click on the photo to see it full-screen)

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A grasshopper sits on one of the last remaining blossoms of stiff sunflower, an early blooming perennial sunflower - most common in the sandier soils of our prairies.

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Our seed harvest crew is swimming through the tall grasses and late yellow flowers to find ripe seeds from shorter plants that bloomed earlier this year. In this photo, Mardell Jasnowski (left) and Nanette Whitten (right) look for black-eyed Susan seeds in the burned/grazed portion of a prairie. A light stocking rate and an unexpectedly wet season has left even this grazed area with plenty of tall growth.

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The abundance of yellow makes flowers of any other color really stand out. In this photo, Mardell is harvesting seed near a particularly showy dotted gayfeather plant.

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This cluster of Maximilian sunflower blossoms was arrayed nicely for a photo...

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A tree cricket feeds on pollen from a stiff sunflower, while two grasshoppers do the same on another flower in the background. Tree crickets are omnivorous - feeding on both small insects and plant material.

In another week or so, some of the yellow flowers will start to fade, and the rest will be joined by the whites and lavenders of late season asters.  In the meantime, yellow is definitely the color of the week. 

Enjoy the autumn!