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Fauna in the Flora, part 2 – Denizens of the not-so-deep

When I came to the IMA in 2002, one of the areas assigned to me was the Garden Terrace building and the adjacent Four Seasons Garden.  The building was constructed in 1939-40 by J. K Lilly, Jr. as a recreation center for the estate, including an indoor bowling alley plus indoor and outdoor swimming pools. The surrounding gardens were designed by Louisville-based landscape architect Anne Bruce Haldeman (the garden’s restoration and interpretation of the place of women in landscape architecture is a goal of the IMA Environmental and Historic Preservation Division).

4 seasons pool 2006

Four Seasons 003 compressed

Sadly, the garden’s ornamental pond no longer has working plumbing for pump and filter to help keep the water free of algae.  Dis-satisfied with the use of chlorine and water colorants, I’ve tried a variety of plantings meant to shade the water and absorb some of the nitrogen and phosphorus in the water that feed the algae.  These, plus hand skimming and bi-monthly pumping and mucking-out have mostly worked.

This is all by way of introduction to the surprise benefit of a little anti-mosquito ecosystem.  Not only do large animals like birds (Coopers hawk for example) and squirrels come to drink, in the water there is a community of thumbnail size critters.  The pool is too shallow and hot for fish, but as hitchhikers either on a duck’s feet or on purchased water plants, several species of insects have arrived.  Arriving on their own are dragon and damselfly larvae.  The top predators, lurking in the bottom of the pond, are the 1 to 1.75 inch immatures of species like the Blue Dasher (Pachydiplax longipennis)  or  Green Darner (Anax junius) eat whoever they can catch – from mosquito larvae to their siblings.

Just as hungry are the critters you are likely to notice skittering on or near the surface: Water Striders (Neogerris hessione) and Backswimmers (Notonecta undulate aka Coraxia sp ).  They will grab adult mosquitos trying to lay eggs, or gobble-up larvae that manage to hatch.  One finds very very few mosquito “wrigglers” in this still pool.

Nov 20 pachy Blue Dasher bugguide iowa st u

Blue Dasher

Water Strider

As Leeuwenhoek wrote in 1676 of his early microscopy observations “… This was to me, among all  the marvels that I have discovered in Nature,  the most marvelous of all; and I must say for  my part, that no greater pleasure has yet come  to my eye than these spectacles of so many  thousands of living creatures in a small drop of  water….” But these marvels here can be viewed with your unaided eye if you simply stop to look.

Coopers hawk drinks at 4 seasons

Coopers Hawk

Photographing this miniature menagerie was beyond my skill.  I turned to some super fun websites from Iowa State University, the Univ of Michigan – Dearborn campus (where I spent many enjoyable afternoons), and the Roger Tory Peterson Institue in New York (Roger Tory Peterson Institute of Natural History ).    Let us all thank these patient naturalists!

Filed under: Horticulture

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