“The Botanists Among Us: Host plant specialization in insects”

It’s been a busy week for me—just two days after doing a presentation on tiger beetles to the Webster Groves Nature Society’s Entomology Group, I gave a talk to the St. Louis Chapter of the Missouri Native Plant Society. As implied by the title, the talk focused on host plant specialization among insects, first covering the major groups of plant-feeding insects and the evolutionary themes involved in adaption to (and away from) plant-feeding, then moving to examples of different types of host plant specificity and highlighting some of the more interesting insects that I’ve encountered (and managed to photograph) over the years.

Like my talk two nights earlier, it was another fun and lighthearted conversation with a highly engaged crowd, and I appreciate the great interest shown by a group that is normally much more focused on plants than on insects. Once again, it was well-attended locally, but for the benefit of those who were not able to attend the meeting in person and that may be interested in this subject, I’ve prepared a PDF version* of the presentation that you can download and peruse at your convenience.

* All content is copyrighted and may not be reproduced or distributed without written consent.

© Ted C. MacRae 2019

BugShot 2011 – Final Thoughts

As I suspected would be the case,  has proven to be an especially difficult challenge.  As a result, instead of posting the answer tonight I’m going to give folks another day to make their play for points (remember, nobody walks away empty-handed).  In the meantime, I’ve had a chance to ruminate over this past weekend’s BugShot insect photography workshop at Shaw Nature Reserve in Gray Summit, Missouri, and now seems to be an appropriate time to post some final thoughts while they’re still fresh in my mind. Suffice it to say that it was an incredible experience—both technically and socially.  I learned far more than I thought possible (and hope I can remember even a portion of it) and made some great friends in the process.  It’s really not possible for me to summarize here all of the techniques, insights, equipment choices, etc. that were covered, nor do I want to—such a list would be boring to read and not very meaningful without the context to go with it.  What I would like to do is shout out a few people who, beyond the collective, helped make the weekend what it was for me.

Instructors.  The three instructors, all accomplished insect photographers of the highest caliber, typified three very different yet complimentary approaches to the art.  Alex Wild (University of Illinois), ant photographer extraordinaire and author of the insect blog I’ve most tried to emulate, gave me tremendous insight on lighting and practical approaches on how to use it effectively.  My discussions with John Abbott (University of Texas) about equipment will be very helpful for the type of photography that I like to do (I’m not sure I’m ready for the tripod yet, but maybe the other ideas we discussed will be the “slippery slope”).  Finally, I thoroughly enjoyed my time with Thomas Shahan (Norman, Oklahoma), whose great artistic insight helped me see a whole new world of possibilities for tiger beetle portraiture.  I must admit to feeling a little star-struck when I first began talking to him, but his infectious enthusiasm and exuberance quickly put me at ease.

Friends.  I can’t begin to list everybody whose company I enjoyed, but standouts include Jo Holly (Alex’s better half!), as well as fellow bloggers Crystal, Lee, Dave, and DragonflyWoman.  Even though I only met them this weekend, it was if I had known them for years.  My time “fishing” tiger beetle larvae with Crystal and Lee was not only a highlight of the trip (watching them “jump” as the larva came flying up and out of the burrow was a real treat), but also represented a discovery in the truest sense of the word (as will become clear in a future post).  No discussion of friends would be complete without mentioning James Trager, not only for opening up Shaw Nature Reserve to this weekend’s event, but also for the access he’s given me over the past several years and our frequent, humorous email discussions about all things entomological (or botanical, ecological, etc.).

Gratitudes.  I want to thank Alex for inviting me to take part in this event as something more than just an attendee.  I hope my contribution, however small, was beneficial.  My thanks also to Patsy Hodge, who was so helpful and gracious to me in the days leading up to and during the event.  I also appreciate the kind comments that many of the attendees made to me about my blog and my photographs—your encouragement means a lot to me.

Regrets.  In an event like this, packed as it was with seminars and group discussions, it is sad but unavoidable that one cannot spend at least a little time with each and every person in attendance.  To those that I did have a chance to talk to, the pleasure was all mine.  To those that I missed, I will catch you next time!

I think I’ll close with this minimally processed photograph of what I take to be Misumenoides formosipes (whitebanded crab spider) and its honey bee (Apis mellifera) prey.  Although I photographed this spider using flash and looking straight up into an overcast sky, I managed to properly illuminate the subject and avoid blown yellows and an all-black background by using some of the very techniques and principles that I had just learned earlier that day.  I hope to learn more at BugShot 2012!

Misumenoides formosipes (whitebanded crab spider) | Shaw Nature Reserve, Franklin Co., Missouri

Promiscuous Plants

Naturalists have long been aware of the greater tendency for plants than for animals to create viable interspecies hybrids. This is attributable not only (as some might expect) to a higher likelihood of passive plants whose mating is mediated by pollen-hungry insects, or the wind, to hybridize more often, but rather to a greater ability of plants, with the simpler design of their anatomies, successfully to build a functioning organism with a Gemisch of genes from parents of different species. Such hybrids occur naturally, and are often reported in regional floras. Further, the advent of modern techniques for characterizing DNA has revealed that hybridizations of yore have given rise to numerous species, and higher lineages, in plants, in fungi, and to a lesser extent in animals.

My recent wanderings in quest of fall flora photos at Shaw Nature Reserve really brought this phenomenon of admixture of species to mind as I was examining populations of the three Gentiana species that live at the reserve. All three are fairly recent introductions at SNR, added to the flora in several locations in our prairie and wetland habitat reconstruction program. Hybridization among these gentian populations was first brought home in my observation over the last three years of increasing numbers of purplish and bluish and outright blue individuals in a population that was originally pure white gentian – Gentiana alba. This population was sowed in the mid-1990s as part of a mesic prairie reconstruction in the watershed of our wetland complex.

Gentiana alba, G. andrewsii and their lavender tinted hybrid growing side by side at Shaw Nature Reserve.

Pale or white bottle gentian, in "pure" form.

A few years later, 50 or so meters distant, separated by a dense row of trees and shrubs, and in a much wetter habitat in which water pools after every rain and seeps subsurficially much of the year, blue bottle gentian – G. andrewsii — was sowed into a wet prairie / sedge meadow reconstruction.

The rich blue flowers of the blue bottle gentian, Gentiana andrewsii

At first the two populations grew independently and remained separate, but what I surmise was a combination of water borne seed transport (along the shore of a pond whose edge both populations are near), and bumblebee borne pollen transport, conspired to bring gametes of the two species together, creating what population geneticists call a hybrid swarm, and what taxonomists call a — well, I can’t write it in polite company such as my readers.

Observe in the sequence of images above how a bumblebee gyne (a potential queen of one of next year’s annual bumblebee colonies) pries open a bottle gentian flower and dives in for a long drink of nectar at the base of the large vessel. Apparently the nectar is copious, because bumblebees may remain in a single gentian flower for up to a minute.

The result of pollen transport among pale and blue bottle gentians, a hybrid of intermediate characteristics.

While there are other populations of both species on the reserve (one hopes, out of bumblebee range from each other) that may retain their genetic integrity, the rampantness of the admixture at this site does give me pause.

And it gets worse! — On drier ground up the slope, among a dense planting dominated by prairie dropseed and little bluestem grasses,  a third gentian known as downy or prairie gentian – Gentiana puberulenta – was established from a seed mix sowed 10 years ago to convert the watershed of the reserve’s wetlands to prairie vegetation.

Unlike the two previously mentioned species and their hybrids, the downy gentian's petals open wide at anthesis, admitting entry to small bees and even to spindly-legged potential pollinators such as syrphid flies.

And now those perverse bumblebees have gone and defied the laws of speciesness and created what appear to be hybrids of this third gentian species with the other two. Honestly, I don’t know whether to feel that I have done some sort of wrong by creating the situation that allowed this to happen … or simply to be intrigued by this unforeseen outcome of my work, and to wonder what will come of it after I’m gone?

The gentian in the upper photo appears to be the offspring of a cross between white and downy gentian parents, while the one in the lower photo appears to be the result of a cross between blue bottle and downy gentian.

BitB Best of 2009

In my first post of 2009, I looked back at the photographs I had posted during 2008 and picked some of my personal favorites. I hesitated then to call myself a photographer (and still do), but I at least now have suitable equipment to aid in my progress toward that eventual goal. I have learned much over the past six months in my first attempt at serious insect macrophotography (prioritizing in situ field photographs of unmanipulated subjects as a matter of personal choice).  Through this, I’ve come to realize the following skills to be the most important for success:  

  1. Composition
  2. Understanding lighting
  3. Knowing how to use a flash
  4. Knowledge of the subject

I’ll give myself a “A” in the last of these, but in the other areas I still have much to learn. With this caveat, and for the last post of 2009, I offer the following twelve photographs as my final choices for the 2nd Annual “Best of BitB”:  

Best beetle

Cylindera celeripes (swift tiger beetle), Woodward Co., Oklahoma

From Revisiting the Swift Tiger Beetle – Part 1 (June 30).  A decent enough photograph, especially considering that I’d had my camera for about a month when I took it.  However, the discovery of robust populations of this formerly rare and enigmatic species throughout northwestern Oklahoma (and later also in northwestern Missouri) was the most significant find of the 2009 field season, and this photograph is the best capture of that moment.

Best fly

Stylogaster neglecta, a species of thickheaded fly

From Overlooked, needle-bellied, thick-headed fly (Aug 14).  One of my first good “black background” shots.  The white tip of the abdomen compliments the white flower stamens against the background.

Best “true” bug

Beameria venosa, a prairie obligate cicada

From North America’s smallest cicada (Aug 4).  So many different shades of green with white frosting on the bug’s body.  I tried taking this shot in portrait and it just didn’t work—I liked this landscape shot much better.

Best predator

Promachus hinei (Hines giant robber fly) & Ceratina sp. (small carpenter bee) prey

From Prey bee mine (Sept 14).  Robber flies are immensely photogenic, especially those in the genus Promachus due to their prominent “beards.”

Best camoflauge

Dicerca obscura on bark of dead persimmon

From The “obscure” Dicerca (June 19).  Sparkling and gaudy as specimens in a cabinet, the coloration of many jewel beetles actually helps them blend almost perfectly with the bark of their preferred tree hosts.

Best immature insect

Tetracha floridana (Florida metallic tiger beetle) 3rd-instar larva

From Anatomy of a Tiger Beetle Larva (Oct 22).  “Otherwordly” is invariably the first word that comes to mind when someone sees a tiger beetle larva for the first time.  I was lucky enough to get this one in profile with a nice view of its abdominal hump and its curious hooks.

Best arachnid

Centruroides vittatus (striped bark scorpion)

From A face only a mother could love (Oct 6).  Despite some minor depth-of-field problems with this photograph, I’m fascinated by its “smile.”

Best reptile

Eastern collared lizard (Crotaphytus collaris collaris) adult male

From North America’s most beautiful lizard (July 10).  A simply spectacular lizard—all I had to do was frame it well and get the flash right.

Best wildflower

Spiranthes magnicamporum (Great Plains ladies

From Great Plains Ladies’-tresses (Dec 7).  Few flowers are as photogenic as orchids, even native terrestrials with minute flowers such as this one.  I like the frosty texture of the lip and the starkness of the white flower on the black background.

Best natural history moment

Thermoregulatory behavior by Ellipsoptera hirtilabris (moustached tiger beetle)

From Tiger Beetles Agree—It’s Hot in Florida! (Dec 18). I chose this photo for the classic “stilting” and “sun-facing” thermoregulatory behaviors exhibited by this tiger beetle on a blistering hot day in Florida.

Best closeup

Megaphasma denticrus (giant walkingstick)

From North America’s longest insect (Aug 21).  I haven’t tried a whole lot of super close-up photographs yet.  I liked the combination of blue and brown colors on the black background.

Best Landscape

Sand Harbor Overlook, Lake Tahoe, Nevada

From Sand Harbor Overlook, Nevada (March 23).   My choice for “best landscape” again comes from Lake Tahoe.  This is not a great photo technically—I was still using a point-and-shoot and had to deal with foreground sun.  However, none of the other photos I took during my March visit to the area captivate me like this one.  I like the mix of colors with the silhouetted appearance of the trees on the point.

Copyright © Ted C. MacRae 2009

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Prey bee mine

Promachus hinei preying upon a small carpenter bee

Promachus hinei preying upon a small carpenter bee

Robber flies of the genus Promachus – the so-called “giant robber flies” – are among the more conspicuous and fearless predators seen in Missouri’s glades. Able to capture almost any flying insect regardless of size, this individual – seen at Long Bald Glade Natural Area in Caney Mountain Conservation Area – was found snacking on what, according to my hymenopterist friend Mike Arduser, appears to be a female individual of the genus Ceratina (the so-called small carpenter bees in the family Apidae). Of the three “tiger-striped” (referring to the yellow and black striping of the abdomen) species of Promachus in the eastern U.S. species, P. hinei is the most common in Missouri. It is distinguished from the more southeastern P. rufipes by its reddish versus black femora and from the more northern P. vertebratus by the larger dark areas dorsally on the abdominal segments and distinctly contrasting two-toned legs. Despite their common name and impressive size, however, they are not the largest robber flies that can be seen in these glades…

Photo details: Canon 100mm macro lens on Canon EOS 50D (manual mode), ISO-100, 1/250 sec, f/13, MT-24EX flash 1/4 power through diffuser caps.

Copyright © Ted C. MacRae 2009

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