Russet browns of big bluestem (Andropogon gerardii) and Indian grass (Sorgastrum nutans) blend with still-green foliage in early autumn at White River Balds Natural Area in southwestern Missouri.
Last week I awoke to refreshingly cool temperatures for the first time in a long time – a brutal heat wave that had gripped the Midwest for some time had finally (if only briefly) passed. Missouri typically experiences substantial heat and humidity during the height of summer, a result of warm, moisture-laden air sweeping up from the Gulf of Mexico and over our mid-continental position. The first cool snap in mid-August, however, usually marks the beginning of the end of protracted heat. High temps may return (and usually do), but they are intermittent and the writing is on the wall – summer’s end is near, and fall is on its way! For most of my life, the coming of fall has always been something to which I looked forward eagerly – it really is my favorite time of year. I don’t just love fall, I adooore it!!! As a result, I sometimes forget that not everyone shares my feelings, so when I mentioned to a colleague last week how excited I was that fall was on the way, I was a little surprised by her less-than-pleased reaction. Kids I can understand – fall means a return to school and the end of fun and sun and no responsibilities. However, for most adults, fall does not entail as dramatic a paradigm shift – we get up and go to work everyday regardless of the season. Indeed, to my colleague, fall was not dreaded so much for what it is but what it portends – winter! I convinced myself that if she was as interested in natural history as I, surely she would appreciate fall as a time of transition in the natural world. This logic proved faulty, however, when just a few days later one of my favorite entomologist/natural historian bloggers voiced a similar lamentation.
Xeric calcareous prairie (''cedar glade'') in southwestern Missouri - habitat for Cicindela obsoleta vulturina.
That the charms of fall are not immediately apparent to everyone is beyond me. Who in middle America doesn’t rejoice the end of long, sweltering days as they cede to the cool days of fall? Who dreads the crisp, clean, autumn air and its pungent, earthy aromas? Who doesn’t marvel as they watch the landscape morph from summer’s monotonous shades of green – its forests becoming a riot of red, orange, and yellow, its grasslands a shifting mosaic of tawny, amber, and gold, and in all places shadows cast long and sharp by a cool yellow sun riding low in a deep blue sky? For the natural historian, fall offers even more than just these sensory gifts – it’s not the end of the season, but rather part of a repeating continuum that includes birth, growth, senescence and quiescence. Plants that have not yet flowered begin to do so in earnest, while those that have shift energy reserves into developing seeds. The spring wildflowers may be long gone, but only now do the delicate blooms of Great Plains Ladies’-tresses orchids rise up on their tiny spires. Grasses also, anonymous during the summer, now reach their zenith – some with seed heads as exquisite as any summer flower. Insects and other animals step up activity, hastily harvesting fall’s bounty to provision nests or fatten their stores in preparation for the long, winter months ahead.
Gypsum Hills in south-central Kansas. Habitat for Cicindela pulchra.
For myself, it is tiger beetles that are fall’s main attraction. Yes, tiger beetles are out during spring and summer as well, but there is something special about the fall tiger beetle fauna. Glittering green, wine red, and vivid white, a number of tiger beetles make a brief appearance in the fall after having spent the summer as larvae, hidden in the ground while feeding on hapless insects that chanced too close to their burrows, until late summer rains triggered pupation and transformation to adulthood. As the rest of the nature prepares for sleep, these gorgeous beetles take their first, tentative steps into the autumn world for a brief session of feeding and play before winter chases them back underground for the winter. Every fall for the past several years now, I have looked forward to the annual fall tiger beetle trip to see some of the different species and the unique landscapes which harbor them. From the “cedar glades” of Missouri’s Ozark Highlands and Gypsum Hills of south-central Kansas, to the Sandhills of central Nebraska and Black Hills of South Dakota, I’ve acquired an even greater passion for a season that I already loved. I’ll never forget the first time I saw Cicindela pulchra (beautiful tiger beetle) flashing iridescently across the barren red clay. I still remember the excitement of seeing my first C. obsoleta vulturina launching itself powerfully from amongst the clumps of big bluestem. I recall my amazement at my first encounter with C. limbata (sandy tiger beetle) as it danced across deep sand blows, undaunted by scouring 30 mph winds. No doubt I have many equally vivid memories awaiting me in the future, as I intend to keep the annual fall tiger beetle trip a long-standing tradition. For this year, I’m hoping that C. pulchra and a few other species will reward a late-September drive to the Nebraska and South Dakota Badlands. Whether they do is almost irrelevant – I love fall, and the chance to see new localities during my favorite time of year will be reward enough.
Copyright © Ted C. MacRae 2010
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Among checkered beetles (family Cleridae), the genus Trichodes contains among the largest and most strikingly-colored species. The 11 North American species of this predominantly Holarctic genus are primarily western in distribution, although two species (T. nuttalli and T. apivorus) do occur in the eastern U.S. The individual in these photos was one of several I encountered feeding on the flowers of a yellow composite in the Gloss Mountains of northwestern Oklahoma during early July. I take them to represent the species T. bibalteatus based on their close resemblance to the holotype of that species from the LeConte Collection in the Museum of Comparative Zoology at Harvard University. While these photographs are admittedly far from perfect, they were about the best I could manage at the time considering the gusty post-storm winds that I encountered atop the mesa where these beetles were found (along with my continuing difficulty in achieving proper exposure with subjects on bright yellow flowers).
The striking colors of adult Trichodes and their frequent association with flowers for feeding and mating belies a more treacherous aspect of their life history. While adults may serve as important pollinators of native plant species (Mawdsley 2004), they also lay their eggs on flowers. The larvae that hatch from these eggs don’t eat the flower itself, but rather attach themselves to bees and wasps that visit the flower as they gather pollen for provisioning their own nests (Linsley & MacSwain 1943). The larvae hitch a ride back to the hymenopteran’s nest, where they then prey on the developing brood and usurp pollen provisions for themselves.
