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

Brazil Bugs #2

A few more photographs from this past week in Campinas, Brazil.  It rained during the afternoon but stopped by the time I arrived back at the hotel, allowing me to stroll the lavishly landscaped grounds during the mild evening hours.  There is a pink-flowered shrub forming a hedge row in back of the hotel that is highly attractive to many types of insects.  The identity of the shrub remains a mystery to me, and most of the insects I’m finding on it I can recognize only to family – I’m hoping the hotel staff will be able to name the former and that the readers of this blog might be able to provide IDs for the latter.

Calycopis sp. poss. origo (Lepidoptera: Lycaenidae). ID by Dave Hubble and Chris Grinter.

It took a bit of effort to find an unobstructed view of this hairstreak butterfly (family Lycaenidae) as it visited the flowers within the shrub.  Every time I tried to move foliage out of the way to get a good view, the butterfly became alarmed and flew to another part of the hedge row.  My antics drew the attention of a hotel worker, who was apparently interested enough in what I was doing to act as a spotter whenever the butterfly flew to help me relocate it.  Eventually I got a few shots that I was happy with, including the above.

A flesh fly (Diptera: Sarcophagidae).

I presume this to be a type of flesh fly (family Sarcophagidae) based on the stout bristles and color pattern that seems typical for the family.  I like the striking contrast in coloration between the fly and the flower.  There are a few fly bloggers who I’m hoping might be able to give a better identification.

A potter/mason wasp? (Hymenoptera: Vespidae).

This appears to me to be some kind of potter or mason wasp (family Vespidae, subfamily Eumeninae) – it was a bit smallish at only about 12mm in length.  I hope one of the knowledgeable wasp bloggers out there (ahem… Eric?) can at least confirm this level of identification and perhaps the tribe or genus as well. 

Azya orbigera (Coleoptera: Coccinellidae). ID by Tucker Lancaster.

Every ladybird beetle (family Coccinellidae) I’ve ever seen is some variation of black and red/orange/yellow and has a smooth, glabrous appearance.  This beetle is cobalt blue with a dense pubescence over the dorsal surface, but it still seems to me to be some type of ladybird beetle.  It was a tiny little thing, so I suppose it could be one of the multitude of small beetle families with which I am unfamiliar.

Quedas sp.? (Hemiptera: Cicadidae).

This cast cicada exuvium was not on the shrub, but on a nearby tree at about eye level.  I really wish I could have seen the cicada that emerged from it, because this is certainly the biggest cicada exuvium I have ever seen.  I was about to simply label it “family Cicadidae” but seem to recall that cicada higher classification is in a bit of flux these days.  At any rate, given its great size I wonder if it might represent one of the giant cicadas in the genus Quesada.

I still have many more insect photographs from the past week and will certainly increase that number over the next week as well.  Stay tuned!

Copyright © Ted C. MacRae 2011

Rush skeletonplant pea gall wasp

Lygodesmia juncea with galls of Antistrophus lygodesmiaepisum (Hymenoptera: Cynipidae) on stem.

The Loess Hills landform along the western edge of Iowa and extreme northwestern Missouri is home to a unique assemblage of plants and animals.  The majority of these are associated with loess hilltop prairies – grassland remnants that have their origins in the hypsithermal maximum of several thousand years ago and that persist as small relicts on the landform’s steep, dry, south- and west-facing slopes.  Many of the plants and animals found in these grassland remnants are more typically found further west in the Great Plains, but hang on in the Loess Hills as hypsithermal relicts.

Antistrophus lygodesmiaepisum galls on stem of Lygodesmia juncea.

One such hypsithermal relict is rush skeletonplant, Lygodesmia juncea, a wirey, leafless-looking plant in the family Asteraceae¹.  More common in the Great Plains, this plant occurs in Missouri only on these loess hilltop prairie remnants.  The first time one encounters this plant, they are left with the impression that the plant bears small, pea-like fruiting structures along the length of its stem.  These are not fruiting structures, however, but galls made by the cynipid wasp Antistrophus lygodesmiaepisum.  Although this insect does not have a common name, it is associated exclusively with L. juncea, as suggested by its specific epithet (which also alludes to the pea-like galls with the suffix -pisum), so I see no reason why this wasp cannot be called the “rush skeletonplant pea gall wasp.”  Some sources variably misspell the genus as Anistrophus (without the first “t”) or the species name as simply pisum, a synonym first introduced by Ashmead in the late 19th century a few years after the species was described (I made both mistakes [and also erroneously referred to L. juncea as skeletonweed] in one of my earliest posts: The Loess Hills in Missouri).  It would seem that Antistrophus lygodesmiaepisum is the correct name, according to Pickering (2009).

¹ Not to be confused with rush skeletonweed, Chondrilla juncea – also in the Asteraceae, which despite the similarity of common names, specific epithet, and general appearance (except with yellow flowers) is an altogether different plant that was introduced from the Mediterranean Region and is now considered an invasive weed in much of the Great Plains.

Antistrophus lygodesmiaepisum larva in gall on stem of Lygodesmia juncea.

Rush skeletonplant exudes a latex-like sap when damaged, making it unpalatable to most grazers – this latex-like sap can be seen when the galls made by the wasps are cut open.  Cynipid wasps are the second most diverse group of gall-making insects behind the gall midges, and many species are mono- or oligophagous (Ronquist and Liljeblad 2001), meaning that they are associated exclusively with a single plant species or group of closely related species.  Antistrophus lygodesmiaepisum is one such monophagous species, thus its occurrence in Missouri, like that of L. juncea, is restricted to the tiny loess hilltop prairie remnants in extreme northwestern Missouri.  In recent years, these prairie relicts have suffered heavily from conversion to agriculture, abusive grazing, and suppression of fire that has led to invasion by woody and exotic plants.  In Missouri, only about 50 acres of loess hilltop prairie remain, and only half of these are in conservation ownership, making it among the most critically imperiled of natural communities in Missouri.  While lacking the conservation charisma of L. juncea and the dozen or so other plants and vertebrates that are restricted in Missouri to these prairie remnants, A. lygodesmiaepisum nevertheless deserves equal consideration as a Missouri species of conservation concern.

I knew this would be a difficult ID Challenge and am quite impressed that at least a few people figured out at least the correct genus.  Tim Eisele scored 8 points in this challenge to not only take the win but also move way up into a 3-way tie for 4th place in the overalls.  Ben Coulter continues to be Mr. Consistency, earning 4 points for 2nd place and retaining his overall lead by an almost insurmountable margin (see what happens when you play every game!).  JasonC beat out the other contenders for the final podium spot on the basis of a bonus point, but the hot contest continues to be the battle for 2nd place overall.  Janet Creamer still holds it at 14 pts, but there is a veritable gaggle of contenders nipping at her heals – the next few challenges could be interesting.

Photo 1: Canon 100mm macro lens (ISO 100, 1/250 sec, f/2.8).
Photos 2-3: Canon MP-E 65mm 1-5X macro lens (ISO 100, 1/250 sec, f/14).
All photos: Canon 50D , Canon MT-24EX flash w/ Sto-Fen + GFPuffer diffusers. Typical post-processing (levels, minor cropping, unsharp mask).

REFERENCES:

Pickering, J.  2009.  Database of Hymenoptera in America north of Mexico. http://www.discoverlife.org/proceedings/0000/6/html/Cynipidae (accessed 20 Jan 2011).

Ronquist, F. and J. Liljeblad.  2001.  Evolution of the gall wasp-host plant association.  Evolution 55(12):2503–2522.

Copyright © Ted C. MacRae 2011

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.

A wiley wasp

[The following is an invited post by Alex Wild of Myrmecos blog]

Little did Ted know that giving me the keys to his beetle blog meant I’d be able  to use his own soapbox to convince everyone that Hymenoptera (the ants, bees, and wasps) are just waaaayyyyy cooler than Coleoptera.

Exhibit A:

Leucopsis sp. ovipositing into a solitary bee nest

Meet Leucospis. This colorful insect, about a centimeter in length, is a parasite of wood-nesting bees and wasps. In this photo she is drilling down through a leafcutter bee nest to lay her egg in one of the bee’s sealed cells. There, her larva will consume the developing bee.

Leucospid wasps aren’t terribly common, so I was rather surprised to see this one on my front porch in downtown Urbana.

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.

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