Brazil Bugs #11 – Formigas cortadeiras

This week is Army Ant Week, and while Alex Wild’s stunning photographs of this diverse and charismatic group reign supreme, some of the cooler bug bloggers are nevertheless getting into the spirit of things with army ant posts of their own.  I have no such photos, but I’m hoping I can sneak onto the bandwagon with these images of leafcutting ants that I photographed last month in Campinas, Brazil.

These were among the first insects I saw during the trip once I got a bit of free time to walk the hotel grounds.  Watching them crawl along the lower edge of the hotel wall was a welcome sight, as nothing says “tropics” to me more than columns of these ants carrying their bits of leaves back to the nest for use in their hidden fungus farms.  While taxonomically they may be unrelated to army ants, their precise single file marches in dutiful service to the colony are as military as it gets.  Army ants may have the jaws, but leaf-cutters have spines – they don’t just carry weapons, they are the weapons!

The thing I like most about leaf-cutter ants is that they are one of the few ant groups that I feel confident enough to hazard an attempt at identification.  Several genera comprise the group, and most people who are at all familiar with them think of the genus Atta first.  However, I recalled reading something on Alex’s blog about spines as a diagnostic character for attine ant genera – sure enough, in this post Alex explains how species in the genus Atta have two pairs of spines on the promesonotum, while those in the genus Acromyrmex bear three pairs.  On this basis, I’ll go out on a limb and declare the individuals in these photos as Acromyrmex sp. (of course, which species is another story – James?  Alex?).  If I’m proved right, it will confirm the worthwhileness of all my blog trolling.  If I am wrong - well, there’s still nothing wrong with idle entertainment.

Copyright © Ted C. MacRae 2011

Brazil Bugs #9 – Formiga hostil


I found this ant crawling over the blossoms of the Ixora shrubs on the grounds of my hotel in Campinas (São Paulo state). Normally I wouldn’t even try to identify a South American ant, but the individual quickly and easily keyed out in the recent revision of North American Formicidae to Formica nigra – apparently a very wide-ranging species!¹

¹ Seriously, I would welcome input from any myrmecophiles out there on the actual identity of this species.

As I started taking some photographs, she seemed to take note of my presence.
With each shot, she seemed to become increasingly more irritated.
Irritation soon gave way to outright hostility.
In short order, the meaning was all too clear – “Stay away from my flower!”
Copyright © Ted C. MacRae 2011

The joys of ecological restoration

Indian paintbrush and lousewort now dominate patches of SNR

I moved to Missouri in the summer of 1988, having experienced 8 years of generous support of my family’s livelihood by my research on the infamous imported fire ants of the US Southeast, and their relatives in South America. When I arrived in the Midwest, I  hoped to land a job as an insect taxonomist in a university or museum, a goal of mine since before entering college. But this dream was one that even before moving to Missouri was dimming, and then receded ever further from the realm of possibility for me (and for traditionally trained taxonomists, generally), once here. So, I began to re-think what I might do with my work life. It would be something, I hoped, that would make some use of all the course work (mostly in entomology and botany) and research (on ant systematics) I had done during my 24 years (!) of getting educated and four additional years as a post-doc. As or more important, whatever job I ended up in would somehow have to allow me to share my life-long love of nature with others.

A museum drawer of ant specimens mounted for taxonomic study, the ants no doubt frustrated by the years of inattention they have received as I have tended to the duties of my day job.

Early in my residence in eastern Missouri, I made the acquaintance of the naturalist at a 2500-acre (1000-hectare) nature reserve outside of St. Louis. Shaw Arboretum, as it was then known, is country cousin to the world-renowned Missouri Botanical Garden, and is named after the Garden’s founder Henry Shaw. Long story short, in the summer of 1990 the naturalist mentioned to me that he would soon retire, the position would become available, and that I ought to apply. So I applied, and was hired as the arboretum’s naturalist in January 1991.

A dolomite glade plant endemic to a few counties in eastern Missouri, this leatherflower was established at SNR in the 1930s, but expanded exponentially after prescribed fire was introduced in the 1990s. Here, an ant characteristic of glades and dry prairies forages on the flower.

When I came on board, the “Arboretum” had mostly ceased to be an arboretum (a formal collection of trees for display, breeding and research), and most folks seemed unable to either pronounce or define the word. Indeed we learned, through a public survey, that the strange name and the stone wall in the front actually dissuaded people unfamiliar with it from entering! Yes, there were a few patches of exotic trees scattered around the property, especially in the conifer collection near the front entrance know as the “Pinetum”, but ever since the Garden had decided around 1930 that it would not, afterall move all of its horticultural operations to this then very rural site (the original intent of its purchase), formal arboretum and botanical garden type activities had been few and far between, and the site began gradually reverting from abandoned farmland to a wilder sort of place, as well as a haven for native biota. Thus, on its 75th anniversary in the year 2000, Shaw Arboretum was renamed Shaw Nature Reserve.

Colony-founding queen bumblebees are the primary actors in loosening pollen with ultrasound from shootingstar anthers, and distributing it about the plant population.

Around that time, my title changed too, to “Restoration Biologist”. The job is multifaceted; presenting public programs and classes on various aspects of the site’s natural history, writing and reviewing articles, acting as liaison to the vigorous regional group of academic ecologists who use the site for research and teaching, a very intermittent personal research program on ants resulting in sporadic publications, and last but certainly not least, ecological restoration.

Ecological restoration, in the broad sense, consists of  two primary practices:

  • Restoration of a natural community to structure and species composition presumed characteristic of an  ;;earlier condition (however arbitrary or ill-defined).
  • Reconstruction of regional, native-like habitats, de novo, using locally acquired native plant propagules in the appropriate settings of soil, hydrology,  slope aspect and climate.

Both  require essentially perpetual, follow-up maintenance, including invasive species control, mowing, haying, grazing, selective timber removal, species richness enhancements, and prescribed burning. All of these have many variations and nuances in application, and there can be impassioned arguments about their implementation in the literature, at conferences, and in forums and blogs on ecological restoration, native plants, butterflies, beetles, etc..

An ecologically conservative lily ally of undisturbed moist soil habitats now thrives in prairie plantings at the Reserve.

Attitudes about ecological restoration vary, among practitioners, among sociologists and philosophers, and in the general public. One broad attitudinal schism lies along the lines of  whether ecological restoration activities are some sort of primitivist, grand-scale gardening, or do they represent ecologically valid landscape conservation? Another question some pose is to what extent we should interfere with “natural successsion”? Be this as it may be, most people with functioning sensory perception agree the results can be very beautiful. The loveliness of the mosaic of colors in the herb layer of a spring woodland is inarguable, especially so after it has had its woody stem density reduced, and had the leaf litter burned off, to allow more light, rain and seeds to the soil surface — even where there is genuine concern about damage to invertebrate assemblages residing in forest duff. A waving meadow of grasses and flowers in a tallgrass prairie planting, intended to replace just a few of the tens of millions of acres of this ecosystem that have succumbed to the plow, has its own grand beauty, though its per-square-meter species density of plant species remains less than half that of a native prairie remnant and it is dominated mainly by habitat-generalist insect species rather than prairie specialists, even after 30 or more years.

A self-introduced grassland ant forages among a thriving, human-introduced population of this wet prairie gentian.

The smaller, daily rewards of restoration, to the practicing ecological restorationist and to those who visit his or her work, are many. Over 20 years, in the opened-up woods, restored glades and prairie and wetland plantings at SNR, I repeatedly have enjoyed the “sudden appearance” and increase in populations of ant species (of course) that I never observed during my early years of working at SNR (then scouring it for purposes of preparing an annotated ant list). The feeling I get upon discovering that a grouping of shooting star, royal catchfly, bunch flower or bottle gentian plants, are in bloom at a site where I spread their seeds five, seven, or even ten years earlier is a bit like that one feels when a child is born. The spontaneous colonization of SNR grassland plantings by prairie ragged orchid never fails to amaze me. Bird, or frog, or katydid and cricket songs in a former crop field or pasture, as the “restored” vegetation fills in and matures, is as pleasing to my ear as it is to my soul.

A few days ago (in early July), the director of the Reserve came to my office asking if I had noticed a purply pink, “possibly orchid” flower growing on a section of a berm (planted with native vegetation) in our 32-acre wetland complex. I had not been in the area recently, but headed right out to see what it was. Joyously, and not a little surprised, I learned that seeds of the purple fringeless orchid, sowed at a location nearby 17 years previously, had washed to this site, taken root, and as terrestrial orchids are wont to do, flowered after so many years!

The black-legged greater meadow katydid thrives in low areas and near bodies of water in SNR

The prairie ragged orchid began to appear in old fields and prairie plantings where prescribed burning occurs at SNR. It has not been seen in fields maintained exclusively by mowing or haying.

The purple fringeless orchid surprised the restorationist and St. Louis area botanists by flowering in the SNR wetland area 17 years after the original sowing.

Copyright © James Trager 2010

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Collecting in Australia’s remote McIlwraith range

The following is an invited post by Alex Wild of Myrmecos Blog:

Myrmecologists Gary Alpert & Phil Ward mucking about with magnetic termites. Cape York Peninsula, Australia, 2004.

Ted MacRae so graciously guest blogged for me last week, so I figured it’s time to turn this around and send one Ted’s way. One of the great joys of Beetles in the Bush is Ted’s photojournalistic coverage of various insect collecting adventures. In that vein, I will recount an Australian expedition with famous ant guys Gary Alpert and Phil Ward from back in 2004. I never blogged the trip because, hey, I didn’t blog back then.

Read more of this post

Revision of the Formicidae of North America

Formica meganigra guarding a nest entrance.

I recently came across this ant in the southeastern Missouri Ozarks sitting in a hole in the trunk of a standing dead black oak (Quercus velutinus) tree, apparently guarding the entrance to its nest. This big black ant is frequently associated with dead wood; however, this is the first time I’ve noticed one guarding the entrance to its nest. Other workers coming back to the nest were greeted by this individual by a quick rubbing of antennae and then allowed to pass. The close approach of my camera apparently was not very welcome by the ant, who responded by showing off his *her* impressive choppers.

In trying to determine the species name for this ant, it became clear to me that myrmecologists have made things far more complicated than they really need to be. When I was a kid, ant identification was easy – there were black ants and red ants, and within those two main guilds some were big, some were not so big, and some were really small.  Peter Yeeles alluded to this traditional classification in a recent comment at Fall to Climb, which the Geek herself later modified to recognize ants that were neither black nor red.  In that classification, this is clearly a big black ant; however, the myrmecologists have unnecessarily split this species up into multiple genera and species based on inconsequential characters such as punctures on the head, clypeal notches, hairy scapes, etc.  I propose to bring a measure of sanity back to ant identification in North America with a revised key to the family (below).  It is based on the traditional classification but also recognizes the introduction in recent years of an alien species that stings and has colonized a large part of the southern United States (we didn’t have those when I was a kid).  In offering this simplified classification, it is my hope that school children across the country – naturally curious about ants and other insects – will no longer have their budding interest squashed by the ponderous, complex ant identification system that has become so fashionable in recent years.

Photo Details: Canon MP-E 65mm 1-5X macro lens on Canon 50D, ISO 100, 1/250 sec, f/14, MT-24EX flash 1/8 power w/ Sto-Fen diffusers.

Revised Key to Formicidae of North America

.
1 Color black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1′ Color not black . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 (1) Enormous. . . . . . . . . . . . . . . . . . . . . . Formica meganigra (big black ant)
2′ Not enormous. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3 (2′) Regular size . . . . . . . . . . . . . . . . . . . . . . . . . . . Formica nigra (black ant)
3′ Tiny. . . . . . . . . . . . . . . . . . . . . . . . . . Formica micronigra (little black ant)
4 (1′) Color red. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4′ Color yellow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 (4) Can sting. . . . . . . . . . . . . . . . . . . . . . . . . . . . Solenopsis invicta (fire ant)
5′ Can’t sting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Formica rubra (red ant)
6 (4′) Regular size. . . . . . . . . . . . . . . . . . . . . . . . . . . Formica flava (yellow ant)
6′ Tiny . . . . . . . . . . . . . . . . . . . . . . . . . Formica microflava (little yellow ant)

Copyright © Ted C. MacRae 2010

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Pismire Puzzle

I returned home from a much-needed vacation late last night, and even though it was a family trip I have much to share from the past 10 days. However, I must remain coy about where I was for the time being so that I may present this little quiz:

Who am I?

I had planned to post this yesterday, but the best title I could come up with – “Monday Myrmecine Mystery” – was just too similar to a Monday tradition on another blog that we’ve all grown to love.  (Also, I just couldn’t get to it.)  No longer constrained by an M-themed title, I came up with this alternative¹ that I hope will make the 12-year old boy in each of us giggle aloud.

¹ Pismire (from pissemire) is an archaic name of Scandinavian origin for ant. Derived from pisse urine (referring to the smell of formic acid) + mire ant.

What am I doing?

I expect members of the Formicine Guild will jump all over this, so I should probably make this quiz about more than just the name of the ant (which I don’t know, so does that make this an illegal quiz?).  Maybe I should offer double points to non-myrmecologists for a proper ID (but then, I would need the consensus of the myrmecologists – perhaps a conflict of interest?).

Why do I do this?

I could also offer points for correctly guessing what the ant is carrying – which again I wasn’t able to figure out, so I guess points will have to be awarded for the most plausible explanation.  What I do know is the ant carried this carcass while meandering aimlessly over the same patch of ground – occasionally stopping very briefly to dig its jaws into it before resuming its wanderings.  I followed the ant for about 10 minutes, and it never left an area of about 1 square foot – no nest nearby that I could see, no direction to its travels, no apparent purpose to its labors.

This is where I live.

I most definitely know where I was, so firm points are on offer for correctly guessing the answer to that question – either on the basis of the ant ID or the above photograph of its habitat.  Yes, that is snow on the ground – lots of it!

Copyright © Ted C. MacRae 2010

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The Inexorable March of Spring!

Granted, the progress of spring seems to advance in halting baby steps with occasional falls onto its muddy bottom, rather than as a determined forward march, but spring is welcome, no matter how it arrives. When little green tips start poking up and there’s a bit of that “spring smell” in the air, I simply must get out and catch up on the status of Nature — the old-fashioned way (she doesn’t have a Facebook account). Over the last week, I’ve gone forth in search of signs that everything else living is about as tired of winter as I am, and wants to get this spring show on the road! There is already so much happening, I can’t recount it all here — A partial list of unphotographed notables: owls breeding; hawks nesting; woodcocks doing their silly, repetitive and almost invisible (because it’s nearly dark) courtship displays; wood ducks on forest ponds; year-round resident songbirds reestablishing territories; spring peepers, chorus frogs, wood frogs and southern leopard frogs singing, especially in the fishless ponds; winter crane flies and midges swarming in sun flecks in the woods; wild filberts, silver and red maples flowering, etc…

Formica pallidefulva sniffs the spring air


Of course, I look for the first ants out at this time of year, though with the exception of 10 March, when the temperature exceeded 70F, they haven’t been notably active. However, that afternoon I encountered, among others, a worker of Formica pallidefulva poking its head out cautiously to sniff the spring air. This is one of my favorite local ants — largish (5-6mm), abundant, active in daylight even when it’s hot, usually shiny bronzy red to red-brown, usually with a darker gaster (the apparent abdomen of ants) around here, but ranging from a beautiful reddish gold (in the deep South) to almost pure black-coffee brown (New England and southern Canada) across its wide geographic occurrence (Rocky Mountain foothills of Wyoming to New Mexico, all the way east to Québec and Florida). It has the added charm of being the host species to a wide range of social-parasitic and dulotic (“slave-making”) ants both in its own and in another closely related genus, with which it lives in temporary or permanent mixed colonies (as with the Polyergus illustrated in my last post). The image below of these ants bringing home a charred earthworm was taken almost one year ago, as one of Shaw Nature Reserve’s prairie areas was beginning to resprout after a prescribed burn a few weeks earlier. Ants will take their food raw or cooked!

Formica pallidefulva with charred earthworm


Prenolepis imparis alate in the clutches of a gerrid

Another ant I mentioned last time I was with you, Prenolepis imparis, has the distinction of being the only ant in our fauna that has mating flights while there is still a good chance of frost in the forecast for the next few weeks. In this picture of a mating pair at  BugGuide, note the size difference that inspires their name “imparis”, Latin for disparate. Any time after mid-February when it is sunny and not too windy, and the temperature rises above 65F, the winged males and females reared the preceeding fall, fly out to partake of a grand insectan orgy. Typically, they have big flights on the first couple of appropriately warm days, then some smaller ones (i.e., fewer individuals participating) over the next few weeks. The flying males look like gnats, bobbing up and down in drifting swarms, a few feet off the ground over a shrub, near a woodland edge or in a sunny opening. (One of my co-workers got into the midst of a group of such swarms once when we were conducting a prescribed burn in a wooded area, and I recall her commenting she “felt like Pigpen with all the little bugs flying around”!) The much larger, golden-brown females lift slowly off the ground, fly ploddingly (or is it seductively?) through the male swarms, are there mobbed by the tiny fellows, and then glide away and slightly downward, mating in flight with the winner of the males’ tussling. Rather clumsy fliers, the females do not always land in a good spot, as occurred to this hapless one that ended up as a feast for a water strider. Those that survive break off their wings, dig a burrow, seal themselves in, and raise a small brood of workers on food produced in their own bodies (like say, milk in mammals or “cropmilk” in doves and some other birds.)

But lest you to think I only have eyes for ants, I feel indeed fortunate to have encountered a tarantula this week, of the same species as Ted recently posted and I didn’t even have to go to Oklahoma for it. This bedraggled individual was at the mouth of its completely flooded burrow in what is most often a very dry habitat — a dolomite glade. Stunned and muddy at the time, my guess is this creature, belonging to a resilient and ancient lineage, will dry off, clean up, and saunter away as soon as she warms up.

Aphonopelma hentzi in flooded burrow


And speaking of emerging from flooded burrows, how about this handsome fellow, a male three-toed box turtle, his sex revealed by his bright orange and red markings, coming up for a breather? In truth, it was perhaps only just warm enough to make him need air, but not really enough so for him to be up and about, so he just sat there, nearly immobile, looking pretty, notwithstanding mud and leaves glued onto his shell.

Male box turtle emerges


Copyright © James C. Trager 2010

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Ants invade Beetles in the Bush!

For months now, your Beetles in the Bush host, Ted, has been nudging me to blog, in the end resorting to offering me a guest blogger gig at BitB. Given this golden opportunity, I’ve decided to utilize my web-logging debut to introduce my favorite insects, the fabulous Formicidae. First, a disclaimer: I have not mastered ant photography, and so will rely on the undisputed king of ant photographers, Alex Wild, through links to his numerous, unexcelled images.

Since about age 5, I can remember being interested in virtually anything living, but especially in small, active creatures. From the beginning, I have had a particular attraction to ants. With some notable exceptions, and aside from the pulchritudinous feature of their svelte waists, ants aren’t what most folks would call pretty, but they are — How else to say it? — just plain “cool”!

First, who are they and where do they come from? Ants constitute a single family, Formicidae, within the insect order Hymenoptera, so their relatives are wasps, bees, sawflies, horntails, gall wasps, and a vast array of small parasitic wasps that are mostly unappreciated except by specialists who study them. Within Hymenoptera, the ants are considered to belong to the superfamily Vespoidea, along with hornets, paper wasps, potter wasps and other solitary relatives.  The evidence at present indicates the first animals we would call ant had diverged from their common ancestry with these other stinging wasps some time in the Cretaceous, 130 million years ago, more or less.  Ants are classified in a varying number of subfamilies, currently at about 20. Fossils in amber up to 100 million years old represent early members of several modern subfamilies, and a few extinct groups. Most of us in the Northern Hemisphere Temperate Zone are familiar only with the big two subfamilies, Formicinae (carpenter ants, weaver ants, honey ants, etc.) and Myrmicinae (fire ants, harvester ants, leaf-cutter ants, etc.). In much of North America, folks may also be familiar with an abundant member of another subfamily, Dolichoderinae, namely odorous house ants, which frequent our gardens, kitchen counters, wall spaces, and even electrical outlets, especially in spring.

Ants are a conspicuous and often dominant presence in the World of the Little (or, what Piotr Nascrecki, in one of my favorite books, calls the ”Smaller Majority” ). It is difficult for any observant person to sit still, outdoors in good weather, and not begin to see ants doing what ants do. They scurry about singly, in pairs or threesomes or foursomes, or in long lines, or columns. Our notice may be further piqued by their habit of transporting sundry bits of biomass or mineromass (pebbles, etc.).  Often this is just taking out the inedible food waste, or sawdust or soil excavated while expanding or remodeling their nests.  Less visibly, because more diffusely in space, ants carry a variety of items from foraging to their nests to provide nutrition for their colonies, or to add mass or create functional structure to their nests (to create better drainage, to provide incubation space for developing brood, and in some desert ants, to capture dew). In one of the most spectacular examples of ants transporting things, the so-called “slave-making” ants carry home the mature brood of a related species, these young ants later maturing in the brood-robbers’ nest to become its work force!

Shiny red workers of Polyergus lucidus return with pupae pillaged from a nest of Formica incerta several meters away. Two brown and differently proportioned workers of the latter that matured from raids earlier in the life of this Polyergus colony may be seen at the right of the photo.

Perhaps, not so widely known is that most of what most ants carry home is not some large, heavy particle in their mandibles, but rather is liquid carried in an expansible section of their esophagus called the crop. Because of the fine diameter of their gullets, adult ants cannot eat anything other than the most minute solid particles (e.g., pollen grains, loose cells from their prey).  Solid items may be cut up to feed to the legless, pale larvae, or the larvae may even be placed directly upon the killed prey to bite into it and feed on their own, using their flexible “necks”.  Adult ants get pre-digested food in return, in the form of glandular secretions loosely termed saliva, but which may be either a glandular secretion from the larva itself or simplify pre-liquefied flesh of prey lapped up from the larva’s messy eating.  In some lineages, known as Dracula ants, adults actually “bleed” the larvae through rapidly healing wounds made at particular locations on the larval exoskeleton.

Okay, I need to get back to my regular work, so let’s bring this home (to winter in the United States). Many of us are now in the dead of winter, or so it would seem. But, on sunny days, sap is beginning to flow upward in maple and other trees, and one ant species may actually be seen, creeping slowly through the woods, in search of dead arthropods and earthworms, or perhaps some sweet sap oozing from a sapsucker wound in a tree. This is Prenolepis imparis, sometimes called “winter honeypot ant”. This is a partial misnomer. While foragers may indeed fill their crops to over-full with sweet sap or honeydew, the very bloated “honeypots” in the deep nests of this ant are in fact, fat pots, having converted their food to whitish body fat. This is later converted to a glandular secretion that serves as food for developing larvae.  These ants are likely to be seen anywhere near where oaks of just about any species grow, and the where the soil is moist but well-drained. Look for these shiny little dark brown ants during your walks in the woods, on the sunny days that are sure to increase in number and warmth in the coming months.

Copyright © James C. Trager 2010

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