Three Little Wasps

Here's a trio of neat little wasps:

Netelia sp, IBSP, Lake County, IL 11/1/14

This one's Netelia sp., in the family Ichneumonidae.

Gasteruption sp, Grant Woods FP,
Lake County, IL 7/9/14

This one's Gasteruption sp., in the family Gasteruptiidae.

Proctotrupes sp, IBSP, Lake County, IL 10/24/14

And this is Proctotrupes sp., in the family Proctotrupidae.

If you noticed that none of them are ID'd to species, well, that's what I get for looking at such unassuming little critters. They're very hard to identify beyond genus, usually requiring dissection at some point. This difficulty isn't, though, from a lack of effort on researcher's parts. If you search for papers on these three genera, you'll find plenty of taxonomic and descriptive work. What you won't find much of is theoretical work.

A couple of articles of some interest beyond the taxonomic one include Gokhman & Ãîõìàí's work on chromosomal evolution. (1) What they found, to my eyes, is that while it is possible to trace the evolution of karyotypes in this order (Hymenoptera, that is), evolution at this level is probably too fast for working out higher-level taxonomies. (The second name above is my computer's desperate attempt to render Cyrillic -- try searching for Gokhman on Google Scholar if you want to see it properly.)

Another, by Broad & Quicke, looked at echolocation in parasitoid wasps -- which all three of our critters here are. Apparently by tapping on old logs, tree trunks, etc., the wasps can find caterpillars, beetle grubs, and the like hanging out in the wood, and even estimate how deep they are (2) -- another example of a simply physical problem being solved repeatedly in different lineages.

(1) Gokhman, V. E., & Ãîõìàí, Â. Å. (2011). Morphotypes of chromosome sets and pathways of karyotype evolution of parasitic Hymenoptera Ìîðôîëîãè÷ åñêèå òèïû õðîìîñîìíûõ íàáîðîâ è íàïðàâëåíèÿ ýâîëþöèè êàðèîòèïà ïàðàçèòè÷ åñêèõ ïåðåïîí÷ àòîêðûëûõ (Hymenoptera).

 

(2) Broad, G. R., & Quicke, D. L. (2000). The adaptive significance of host location by vibrational sounding in parasitoid wasps. Proceedings of the Royal Society of London. Series B: Biological Sciences, 267(1460), 2403-2409.

A Proper Mink Coat

This little guy seemed remarkably unconcerned about my presence this afternoon:

This is an American Mink (Neovison vison), a rather large member of the weasel family. He was hunting the rocks along the side of N. Pt. Marina, hoping to find some mice for dinner.

This is the same species that mink coats are made of, and these days they are intensively farmed for their fur. Here in the US and in Canada, this is a cause for concern, since domesticated mink are genetically distinct from wild ones by now. When they escape, some are able to survive, and can dilute the gene pools of wild mink in the area. (1)

In Europe, this is even more of a concern -- in addition to farm escapes, wild mink have been released in a number of countries as a source of fur. As they are semiaquatic predators, it isn't surprising that they've been implicated in declines of muskrats, at least in Poland. (2) (Muskrats are a favored food in their native range as well.) These days, mink control programs are common throughout Europe, (3)  but they are hampered by continuing escapes of domesticated mink. (4)

There does appear to be some hope in this regard, though. Some island populations have actually been eradicated, in part through careful consideration of how the mink respond to trapping pressure. (5) Modelling efforts suggest that eradication may even be possible in some mainland populations. (3)

Of course, my little model is a native mink, and there's no pressure at all to get rid of him. Which means he's still free to consider me a curiosity:

(1) Kidd, A. G., Bowman, J., Lesbarreres, D., & SCHULTE‐HOSTEDDE, A. I. (2009). Hybridization between escaped domestic and wild American mink (Neovison vison). Molecular Ecology, 18(6), 1175-1186.

 

(2) Brzeziński, M., Romanowski, J., Żmihorski, M., & Karpowicz, K. (2010). Muskrat (Ondatra zibethicus) decline after the expansion of American mink (Neovison vison) in Poland. European journal of wildlife research, 56(3), 341-348.

 

(3) Zabala, J., Zuberogoitia, I., & González-Oreja, J. A. (2010). Estimating costs and outcomes of invasive American mink (Neovison vison) management in continental areas: a framework for evidence based control and eradication. Biological invasions, 12(9), 2999-3012.

 

(4) Zalewski, A., Michalska-Parda, A., Bartoszewicz, M., Kozakiewicz, M., & Brzeziński, M. (2010). Multiple introductions determine the genetic structure of an invasive species population: American mink< i> Neovison vison</i> in Poland. Biological Conservation, 143(6), 1355-1363.

 

(5) Bodey, T. W., Bearhop, S., Roy, S. S., Newton, J., & McDonald, R. A. (2010). Behavioural responses of invasive American mink Neovison vison to an eradication campaign, revealed by stable isotope analysis. Journal of applied ecology, 47(1), 114-120.

 

(6) Zalewski, A., Michalska‐Parda, A., Ratkiewicz, M., Kozakiewicz, M., Bartoszewicz, M., & Brzeziński, M. (2011). High mitochondrial DNA diversity of an introduced alien carnivore: comparison of feral and ranch American mink Neovison vison in Poland. Diversity and Distributions, 17(4), 757-768.

 

 

Aquatic Beauties

 Here's a little beauty:

This is a Fragrant Water Lily, Nymphaea odorata. It's one of  approximately 36 species in the genus, itself one of 7 or 8 genera in the family Nymphaeaceae. According to the Flora of North America website, this is one of 9 species of Nymphaea that occur in North America.

The entire family is often referred to as water-lilies, of course, since they are entirely aquatic. They grow rooted to the bottom of ponds and slow rivers, with leaves submerged, emergent, or floating on the surface. The flowers are raised above the surface to some degree, as seen here:

In addition to their beauty, and their ecological importance in warm wetland areas, water lilies are of interest to botanists because of their taxonomic position. They are generally thought of as the second most basal group of angiosperms, branching off from the other flowering plants just after Amborella did so. A recent paper, however, argues that Amborella is the sister group of a Nymphaeaceae - Hydatellaceae clade. (Hydatellaceae is a small family of minute aquatic plants.) This means that the water lilies are direct descendants of that first branch off the flowering plants, basal to all of the other angiosperms.

Water lilies and Hydatellaceae are aquatic plants, but Amborella is a land plant, as are most of the angiosperms. So: were the original angiosperms aquatic, with Amborella climbing onto land, or were they terrestrial, with the water lilies aquatic preference evolving after that next split?

In a similar vein, Amborella has vascular tissue that is missing certain elements normally found in angiosperms (one reason why they've been considered a basal group). But if they're in a clade with two or three other families that do have that tissue, did they somehow lose those elements? Or is this an interesting case of convergent evolution between the Nymphaeaceae and the rest of the angiosperms?

The Evolutionary Root of Flowering Plants. Vadim V. Goremykin, Svetlana V. Nikiforova, Patrick J. Biggs, Bojian Zhong, Peter Delange, William Martin, Stefan Woetzel, Robin A. Atherton, Patricia A. Mclenachan, and Peter J. Lockhart. Syst Biol (2013) 62 (1): 50-61 first published online July 31, 2012 doi:10.1093/sysbio/sys070

Salt-water Musicians?

Here's a critter from deep in the archives (if not so deep in the sea).

This is a Brown Guitarfish (Rhinobatos schlegelii), from the Denver Aquarium. While he looks like a cross between a stingray and a shark, he's actually considered to be in the family Rhinobatidae, in the Order Rajiformes. (That is, he's a ray, but closer to the skates than the stingrays.) He's found in the western Pacific, from Korea to Australia. 1 There are 50 species of these guys, found throughout the warmer oceans of the world. 2  Mostly they hang out in shallow coastal waters, eating snails, clams, and other bottom-dwellers.

I haven't had much luck finding studies that focused on this one, although Fishbase does state that it's a fine eating species, but other species, such as the Common Guitarfish (R. rhinobatos) from the Eastern Atlantic and Mediterannean, and the Shovelnose Guitarfish (R. productus) from the west coast of the US and Mexico, are quite well-studied, from distributions to reproductive biology 3,4,5,6 to genetic variation. 7

That last study found something quite interesting to my mind -- unrecognized genetic differentiation between fish from the west coast of Baja California and those from the Gulf of California just to the east. The authors didn't go so far as to claim the two forms were separate species, but they did point out that this sort of variation should be a concern when we're contemplating conservation or management measures. This species isn't endangered, but several others are, including the Common Guitarfish. (Brown and Shovelnose are listed as data-deficient by the IUCN).8

While the Brown and Shovelnose aren't considered endangered, they are both heavily fished, so all of this study, including the ongoing taxonomic work, are very important, if we want to keep them around.


1) http://www.fishbase.org/summary/Rhinobatos-schlegelii.html

2) http://en.wikipedia.org/wiki/Guitarfish

3) Enajjar, S., Bradai, M. N., & Bouain, A. (2008). New data on the reproductive biology of the common guitarfish of the Gulf of Gabes (southern Tunisia, central Mediterranean). Journal of the Marine Biological Association of the UK, 88(05), 1063-1068.

4) Ismen, A., Yıgın, C., & Ismen, P. (2007). Age, growth, reproductive biology and feed of the common guitarfish (< i> Rhinobatos rhinobatos</i> Linnaeus, 1758) in İskenderun Bay, the eastern Mediterranean Sea. Fisheries Research, 84(2), 263-269.

 

5) Abdel-Aziz, S. H., Khalil, A. N., & Abdel-Maguid, S. A. (1993). Reproductive cycle of the common guitarfish, Rhinobatos rhinobatos (Linnaeus, 1758), in Alexandria waters, Mediterranean Sea. Marine and Freshwater Research, 44(3), 507-517.

 

6) Sandoval-Castillo, J., Rocha-Olivares, A., Villavicencio-Garayzar, C., & Balart, E. (2004). Cryptic isolation of Gulf of California shovelnose guitarfish evidenced by mitochondrial DNA. Marine Biology, 145(5), 983-988.

 

7) Márquez-Farías, J. F. (2007). Reproductive biology of shovelnose guitarfish Rhinobatos productus from the eastern Gulf of California México. Marine biology, 151(4), 1445-1454.

8) The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 16 October 2014.

(Nearly) Lost Wanderers

Early October, and soon we'll be seeing the last of these guys winging their way past the watch:

This is a Peregrine Falcon (Falco peregrinus). The name literally means wanderer, and it's appropriate. They live on every continent except Antarctica, and routinely show up in Hawaii.

There was a time, however, when this would have been an exceptional sight here in Illinois:

Starting after World War II, the US started using DDT to control mosquitoes and other insects. We used a lot of it, much of it for agricultural purposes. We didn't realize, though, that it bioaccumulates, (in other words, the higher trophic level you feed on, the more you absorb) especially in aquatic systems. Neither did we recognize that in larger doses it has serious impacts on calcium metabolism in birds.

Peregrines feed largely on ducks and shorebirds. (Well, today a lot of them feed on pigeons, but that's a rather new development.) That puts them squarely in a high trophic level, at the top of an aquatic system. So it's no surprise that they got doses more than high enough to disrupt calcium uptake. This is especially important for birds, since their eggshells are primarily made up of calcium. In the case of Peregrines, in the eastern US, eggs became so fragile that the females couldn't successfully incubate them. And by the early 1970's, Peregrines were no longer found east of the Mississippi.

After DDT was banned in the US in 1972, several of the most heavily impacted birds began to rebound. (Osprey, Bald Eagles, Brown Pelicans). But there weren't any Peregrines left to start a recovery. Into this gap stepped the folks at the Peregrine Fund. They raised a bunch of money, began to acquire Peregrines from elsewhere, and then learned how to successfully reintroduce them. As a result, they were removed from the US Endangered Species List in 1999.

But where did they come from? Therein lies an interesting debate on the nature of subspecies and the authenticity of our natural history.

The eastern anatum was gone -- there were a few pairs breeding in easternmost Canada that appeared to have been anatum, and that was it. Out west, they were still hanging on in scattered locations. So, what to do? Try to catch a few of the Canadian birds (which might have unfortunate effects on the one wild population left), or bring some western birds east?

Or you could try what the Peregrine Fund actually did -- bring in birds from all over the world, and rely on natural selection to sort out a new subspecies that would be well-suited to this new environment. (And a new environment it is -- many of the original nesting areas have become unsuitable, whereas many of today's birds nest in high-rise buildings in various cities.) These new birds are currently termed "mutts" by many raptor enthusiasts. I've been told that "nothing about Peregrine's nesting in Chicago is natural", to which I reply "What about Chicago IS natural?"

Admittedly, this is a long-term strategy. It will be decades, probably even centuries, before we can expect a population that is homogeneous enough to give it a subspecies designation all its own. But then again, that's how natural selection works.
One of the things that interests me about this is the insistence that the Canadian birds were still anatum, so they should have been used. Yes, they looked like birds from New York or Illinois, (or Florida, even), but does that mean that they would be genetically well-adapted to this area? That's an open question -- for most species, we don't have any idea how closely the genetics follow appearances across populations, and even if we did, we don't know which genes are important in adapting to local conditions. (Or even how closely those genes correlate with environmental variation.)

I do find the debate interesting, but fortunately for my own peace of mind, I find myself in agreement with the Peregrine Fund. This is a neat long-term experiment in applied evolutionary biology, and if we're still willing to do the work in the decades to come it could prove invaluable in helping us learn how species can adapt to the changes we like to make in our environment.

No matter how you feel about the current situation, though, it's neat to know that this shot could be across the sunrise of a new population, and not the sunset of a species:

Turf Birds

Here's a find from a few days ago:

This is an American Golden Plover (Pluvialis dominica). He's migrating through, on his way from the tundra of northern Canada to the pampas of Argentina. As a plover, he would be considered a shorebird, and we did in fact find him on a shore (a lakeshore, but...):

This was at Illinois Beach State Park, here in Lake County. Around here, these birds aren't easy to find. Most of the large plovers that move down the lake turn out to be these guys:

These are Black-bellied Plovers (Pluvialis squatarola). They breed in the same Arctic tundra, but many of them spend the winter along the Gulf and Atlantic Coasts instead.

As I said, Golden Plovers are hard to find here in Lake County. But elsewhere in Illinois... A significant portion of the world's population of this species migrates through central Illinois, where a good day scouring sod farms (with a scope, preferably) can yield several hundred of them. Sod farms, of course, can hardly be considered shorelines, but some "shorebirds" actually prefer them. Here's another example:

This is a Buff-breasted Sandpiper (Calidris subruficollis), another sod farm specialist, and another species more easily found in the Midwest than just about anywhere else.

This preference made sense, when this area was full of prairies, prairie fires, and bison. Now that the bison are gone, most of our prairies are tiny little patches, and prairie fires are carefully managed, they seem to be dependent upon our desire for short, green grass. But sod farms are, after all, businesses, and they have no choice but to respond to the economic environment. These days, many of our local sod farms have been slowly converting to corn, as demand for sod goes down. What this means for Golden Plovers and Buff-breasted Sandpipers, we don't really know. But it does illustrate an intriguing way in which economics can impact the natural world we live in.

A Melodrama For Three Parts

Here's a beautiful little critter that came by our hawkwatch yesterday:

This is a Merlin (Falco columbarius), another small falcon. Whereas Kestrels are all about elegance and grace, Merlin are all about power and speed. We sometimes say that Merlin shouldn't be a two-syllable word, because you don't have the time to say it!

Here's one dining on the wing -- they do this a lot as they migrate south.

What's he eating? Probably a close relative of this guy:

This is a Canada Darner (Aeshna canadensis) that also showed up on the hill yesterday. We don't see many of them, but we do see a lot of Common Green Darners, in the same family. (Although in a different genus -- they're formally known as Anax junius.) They appear to be a favorite snack for migrating Merlin.

Darners are also voracious predators of smaller insects, with darners specializing in flying prey.

This particular guy, though, fell afoul of yet another predator:

This beauty is a Banded Argiope (Argiope trifasciatus). She's a big spider, with a body close to an inch in length, and she's going to need every bit of her size and venom:

You may have heard people talk about the food chain. Some might even understand the concept. But the food chain is a wonderful example of what Jack Cohen and Ian Stewart call Lies to Children. (aka education) Nature is so much more complex than a simple chain -- here we have a notable predator (the darner) being eaten by two other predators (the Merlin and the spider), with nary a producer (i.e. plant) in sight -- any plant is at least two steps back in the system, and possibly more. If we had followed this darner through his entire life, we might well have found him eating a baby Argiope trying to reach a new home. Or we might have seen him eating a mosquito that had just fed on a female Merlin returning to her nest with another dragonfly for her hungry chicks.

Lies to Children refers to simplified stories that we tell children (or college students, etc.) so that later on, they're ready to understand the more complicated truth. Except that science is, in the end, about telling each other stories about how the world works, and since the world is bigger and more complex than our poor brains, we have to tell each other lies as well. We can, of course, hope to find more accurate lies, and who knows, maybe sometimes we do hit the real truth. After all, we really do know more about how the world works than we ever used to. But without a teacher out there to tell us how we did, we can never really know we've got it right. We can figure out that we're less wrong than we once were, though, and that's a useful thing indeed.

Making Sense of Hawks

We started our hawkwatch Saturday, and we've had a few things to look at so far. (The first couple of weeks are always rather slow -- if you want to be sure that you're catching the entire migration, you've got to put up with some slow days.)

This beauty came by last Sunday:

He's an immature Red-tailed Hawk (Buteo jamaicensis). He didn't appear to be migrating, though, which isn't surprising. We know they nest in the park where we count.
On Monday, this lovely lady took a look at our site:

This is a female American Kestrel (Falco sparverius). She had caught something, possibly a grasshopper, and we watched her eat on the wing as she went by.

The Kestrel is, as the Latin name suggests, a falcon, in the family Falconidae and the order Falconiformes. She's got a strongly hooked, sharply pointed bill, strong feet with large pointed claws, and long, sharply pointed wings to enable her to fly very fast and maneuver very efficiently. The hawk is in the family Accipitridae (Accipiter simply means hawk in Latin). While the wings aren't sharply pointed, the bill and feet are very similar, and the wings are still long enough to allow for impressive flying abilities. Both families also specialize in eating not only other animals, but frequently other chordates. It's probably not a surprise that traditionally, then, the Accipitridae has been included in the Falconiformes.

What may be a surprise, though, is that they are no longer placed there. In fact, Accipitridae is now in the order Accipitriformes (formed when they were removed from Falconiformes). What's probably more of a surprise is that the Accipitriformes are now considered to be the sister group to a clade of owls, trogons, hornbills, kingfishers, and woodpeckers, while the Falconiformes are seen as the sister group of a clade composed of songbirds and parrots.

And what should we make of this guy:

This is a Turkey Vulture (Cathartes aura), in the family Cathartidae. The family is strictly New World, with 7 species, 3 of which are found in North America. (There are a few finds that suggest they were more widespread in the Pleistocene.) He has a nicely hooked bill, but the feet aren't nearly as strong, and while he's also a chordate eater, he very rarely kills for a meal. Vultures are patient critters that wait for animals to die on their own before they dine.

Historically, they have been placed in the Falconiformes. Before that order was split, though, the Cathartidae were moved into the Ciconiiformes, with a number of authors arguing that they were actually similar to storks. (This discussion only applies to the Cathartidae -- Old World vultures have always, to my knowledge, been included in the Accipitridae.) Some authors subsequently have placed them in an order all their own, Cathartiformes, while others have actually argued for a label of incertae sedis (aka "we have no idea what these things really are!"). The same large-scale analysis that led to the Accipitriformes, though, supported placing the Cathartidae back with the hawks, and at the moment, the AOU checklist has them in Accipitriformes with the hawks, eagles, kites, and Secretary Bird.

Through it all, we've been faithfully counting all of them, and we'll of course continue to do so. Knowing about the evolutionary history is wonderful, but keeping them around is a pretty important goal as well, and we hope that keeping track of them is a small part of that. With luck, I'll never have to try to communicate the thrill that we used to get watching them sail past.

Oh, and just because, here's a King Vulture (Sarcoramphus papa) from the St. Louis Zoo:

Butterflies, Moths, and...?

Fall semester starts Tuesday, and hawkwatch starts Saturday, so it's about time I put something up. Here's a little selection of moths from this month:

This is a Primrose Moth (Schinia florida):

This one's a Bleeding Flower Moth (Schinia sanguinea):

And this one's a Polymorphic Pondweed Moth (Parapoynx maculalis):

These guys might well make one ask "Why are these moths and not butterflies?" Which might well lead to the question "What IS a moth, anyways?" and "What is a butterfly?" The first version of the answer is, they're all insects in the order Lepidoptera. Wonder of wonders, they're also all of the Lepidoptera; everything in this order is called either a butterfly or a moth. (Well, sort of... more on that in a moment.)

One of the older butterfly guides had an intro where the author tried to answer the question "What is a butterfly?" by saying, roughly, that a butterfly was brightly colored and flew in the daytime. But of course, some things we call moths fit this very nicely. He then pointed out that he's seen crepuscular butterflies in the tropics, so it's not an easy question at all. And if we're using color as a criterion, then what do we make of this guy?


This is a Hackberry Emperor (Asterocampa celtis).

And this is a Common Checkered Skipper (Pyrgis communis):

This last one is the sort of... And that gets us into the heart of the issue. The skippers have been considered a separate suborder, and currently are listed as a superfamily within the Rhopalocera, along with the butterflies (also a superfamily). Most sources do call them butterflies, in any case. The Rhopalocera, though, is listed as one suborder within the Macrolepidoptera, which includes 4 other superfamilies. Although the Macroleps include 60% of the species in the Lepidoptera, they actually include a minority of the superfamilies (and families, not coincidentally). All of those other superfamilies are called moths!

So, what's a butterfly? It's something in the Rhopalocera, possibly excluding the skippers. What's a moth? Any lepidopteran that isn't a butterfly! (Or a skipper....)

Things were often much simpler before we started doing proper phylogenetic analyses, but I'd rather deal with the complications if it means a better understanding of where things came from.

Growing Pains

Mid-semester is always a busy time. The bugs don't care, though, so here's a nice find from last week:

Coral Hairstreak (Satyrium titus), Illinois Beach SP, Lake Co, IL 7/9/2014

This is a Coral Hairstreak, (Satyrium titus). They're quite common around here, and always a welcome sight in July.

Here's what one looked like last month:

Coral Hairstreak (Satyrium titus), Illinois Beach SP, Lake Co, IL 6/14/2014

Everyone knows that caterpillars turn into butterflies, right? (Well, most of them turn into moths, but that's a story for another day.) But what about other insects?

Dragonfly Nymph (order Odonata), College of Lake County, IL, 7/16/2012

Many groups undergo metamorphoses similar to butterflies. This frightening critter is a young dragonfly. (Dragonfly nymphs are very hard to ID to species, I'm afraid.)

Racket-tailed Emerald (Dorocordulia libera), Gander Mt. Forest Preserve,
Lake Co, IL 5/23/2012

And here's an adult, in this case a Racket-tailed Emerald (Dorocordulia libera).

Seaside Grasshopper (Trimerotropis maritima), Illinois Beach SP,
Lake Co, IL 7/21/2013

Here's a Seaside Grasshopper (Trimerotropis maritima). Despite the name, they're quite common in the old sand dunes at Illinois Beach State Park. And here's a young one:

Seaside Grasshopper (Trimerotropis maritima), Illinois Beach SP,
Lake Co, IL 6/12/2014

You can tell it's young by the short, stiff wing pads, compared to the long, mobile wings of the adult. Clearly, though, grasshoppers (like the rest of the order Orthoptera) don't undergo a full metamorphosis. Neither do the true bugs in the order Hemiptera.

So there is variation in metamorphosis in insects. (We don't see it at all in Arachnids - young spiders or scorpions look like tiny versions of their parents.) Any time we see variation across a group, it provides a possible test of evolutionary mechanisms. In this case, Kukalova-Peck discussed the fossil record of insects back in 1978, concluding that metamorphosis had evolved separately in several different lineages. (1) Thirty years later, Belles agreed, arguing that we can trace the more complete, holometabolan lineages through hemimetabolan fossil stages, (2) while still concluding that the story is murky at best.

In 2001, Yang used insect metamorphosis to test the hypothesis that organisms with modular developmental strategies (like metamorphic insects) should show more diversification over time. They found that, indeed, holometabolan lineages showed more diversification than ametabolan or hemimetabolan ones. (3)

(1) Kukalova‐Peck, J. (1978). Origin and evolution of insect wings and their relation to metamorphosis, as documented by the fossil record. Journal of Morphology, 156(1), 53-125.

(2) Belles, X. (2011). Origin and evolution of insect metamorphosis. eLS.

 

(3) Yang, A. S. (2001). Modularity, evolvability, and adaptive radiations: a comparison of the hemi‐and holometabolous insects. Evolution & development, 3(2), 59-72.

Beetles with a Checkered Past (and Future)

It's been a good summer so far for these beauties:

Trichodes nuttali, Illinois Beach SP, Lake Co, IL, 6/29/2014

Enoclerus analis, Lyons Woods FP, Lake Co, IL 7/30/2013

Thanasimus dubius, Lyons Woods FP, Lake Co, IL 6/2/2014

These are all Checkered Beetles, in the family Cleridae. The family is a small one, only 3600 species worldwide, with only 300 or so in North America. (That's about 1% of the 350,000 species of beetle worldwide*, and about 0.1% of the 25,000 beetles recorded from North America.)

They're predators, eating other insects. The larvae often feed on wood-boring larvae, including those of Pine Bark Beetles responsible for quite a few large-scale losses of trees in the western and south-eastern US. Which explains why this little tiny family still warrants over 5,000 citations on Google Scholar.

Interestingly, they use the sex pheromones of their prey to find them. The technical term for this is a kairomone, which is a chemical produced by one species that ends up benefiting another species. Herms, et al. looked at this in the predator-prey pair Ips pini (a bark beetle) and Thanasimus dubius (the last Clerid shown above). (1)  Billings & Cameron showed that different predatory beetles respond to different genera of pine bark beetles, an interesting bit of specialization. (2) (They also showed that pine sawyer beetles, Monochamus titillator, responded to one of the bark beetles. Given their habit of laying eggs in freshly dead pine trees, this makes sense. They only responded to one species of beetle, though, which leads me to wonder if that beetle is more lethal to the pines, or if both the bark beetle and the sawyer beetle show preferences for certain species of pine.)

Beetles can be surprisingly attractive little critters, but it shouldn't surprise me by now just how intriguing their lives can be.

*All of these figures from Bugguide.net.

(1) Herms, D. A., Haack, R. A., & Ayres, B. D. (1991). Variation in semiochemical-mediated prey-predator interaction: Ips pini (Scolytidae) andThanasimus dubius (Cleridae). Journal of chemical ecology, 17(8), 1705-1714.

 

(2) Billings, R. F., & Cameron, R.S. (1984). Kairomonal responses of Coleoptera, Monochamus titillator (Cerambycidae), Thanasimus dubius (Cleridae), and Temnochila virescens (Trogositidae), to behavioral chemicals of southern pine bark beetles (Coleoptera: Scolytidae). Environmental Entomology, 13(6), 1542-1548.

 

Return of the Prairie?

Here's a nice find from this morning, first located by a friend of mine:

Prairie Warbler (Setophaga discolor), Grant Woods FP, Lake Co, IL  6/27/2014

This is a male Prairie Warbler (Setophaga discolor), and he's only the third one I've ever run across in the county. The first one, in fact, I never did manage to see. Thankfully, they have a very distinctive voice -- a slightly buzzy, very musical series of notes running up the scale. Their song always reminds me of Arethra Franklin trying to sing a Northern Parula ditty.

They breed in early-successional shrublands, which are in rather short supply in this area these days. Back in the 70's, though, they bred in Illinois Beach State Park. That habitat hasn't changed much over the years, and I don't know why they disappeared.

I mentioned that this was the third one I've found here? The first two were last year in May. Given that this guy's been singing away for at least two weeks, and he was joined by a second male, I have to wonder if this is a signal of a range expansion back into the county. In the case of this particular male, it's likely to be an unsuccessful one, since he's still singing his heart out at the end of June. (Typically, a male that's found a mate will spend a lot less time singing by now, since there's no longer any need to attract a female.) But that's the way that ranges grow -- the first few birds into a new area will probably not succeed. Once a couple of birds have found mates, and we have a few nestlings who have grown up here, then the next birds to wander into the area will see a reason to stay, and we have a new expected species.

Evolution can be seen as an exploration of the incredibly large universe of possible genetic programs, set against a wildly varying environment of constraints. An occasional individual wanders into new territory, and if it's really lucky, an entire population will someday follow it. But that's an abstract way to view things. Genetic programs only evolve when they're in a body that can actually do things, and in this case, we're seeing the abstract concept of exploration playing out in very concrete, and very musical, little warblers.

Wolves and Bears, Oh My!

Rain threatened all morning, then class in the evening, so here's a couple of zoo shots:

Red Wolf (Canis rufus), Henry Doorley Zoo, Springfield, IL 5/21/2013

This is a Red Wolf (Canis rufus).

Mexican Gray Wolf (C. lupus baileyi), Cheyenne Mountain Zoo, Colorado Springs, CO 12/27/2013

This is a Mexican Gray Wolf (C. lupus baileyi).

At various times, the Red Wolf has been considered a subspecies of the Gray Wolf (thus C. lupus rufus) (1) and a hybrid of Coyotes (C. latrans) and Eastern Gray Wolves (C. lupus lycaon) (2, 3). (It's been argued that Eastern Gray Wolves aren't properly placed in C. lupus, (4) as well.) This is all a rather obscure academic dispute, I suppose. Even most people who care that there are wolves in the US don't know the ins and outs of their relationships. Except for one thing -- Red Wolves are a critically endangered species, with a re-introduced population living on Alligator River NWR in northeastern North Carolina. If they were indeed to be considered a subspecies of the Gray Wolf, the reintroduction program might itself be endangered. Trying to do science well is hard enough. Trying to do it well with this sort of controversy lurking behind every abstract must be a bit of a nightmare.

Here's another couple of critters with similar histories:

Alaskan Brown Bear (Ursus arctos alascensis), Alaska Zoo, Anchorage, AK 8/12/2012

Grizzly Bear (U. arctos horribilis), Cheyenne Mountain Zoo, 12/27/2013

These are both Brown Bears (Ursus arctos), although currently considered different subspecies. There have been quite a few different subspecies described, from as few as 5 to as many as 90! In the 1920's and 1930's, though, the Grizzly (Ursus horribilis) was still considered a separate species. (5) Again, since Grizzlies are listed as endangered, while Brown Bears as a whole aren't, these decisions actually matter. And here's an interesting question for the near future, along these lines:

Polar Bear (U. maritimus), Cincinnati Zoo, Cincinnati, OH 3/29/2012

This, of course, is a Polar Bear (Ursus maritimus). If you're into bears, you've probably heard of the Grolar Bears that have recently been shot in the Arctic reaches of North America. Those would be Ursus maritimus X arctos hybrids. Hybrids between species indicate that those species are closely related, and indeed research suggests divergence times as old as 5 million years (6) and as recent as
150,000 years. (7) While there is evidence from DNA of hybridization, and a couple of older specimens, recent discoveries of wild grolar bears has raised the specter of climate change pushing the two species into more contact, with grizzlies moving north as the climate warms and polar bears spending more time on land as the ice melts. If they are capable of hybridizing, and the hybrids are born into a changing world that favors a melding of the two species, could we see the recently evolved Polar Bear merging back into the Brown Bear they evolved from? And if so, what would we call the resulting population, and how would we deal with it in terms of conservation?

Science is all about trying to refine our view of the world. Often that requires a focus which nearly shuts out all but the little piece we're working on. But the rules our world plays by don't always allow the Ivory Tower approach -- the things we do really do make differences in the world around us.


(1) Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press.
  
(2) VonHolt, BM; et al (12 May 2011). "A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids". Genome Res 21 (8): 1294–305. 

(3) Wayne, R. and S.Jenks. 1991. Mitochondrial DNA analysis supports extensive hybridization of the endangered red wolf (Canis rufus)" Nature 351:565-68.
 
(4) Chambers SM, Fain SR, Fazio B, Amaral M (2012). "An account of the taxonomy of North American wolves from morphological and genetic analyses". North American Fauna 77: 1–67. 

(5) Baggley, G. F. (1936). Status and distribution of the grizzly bear (Ursus horribilis) in the United States. In Transactions of the North American Wildlife Conference (Vol. 1, pp. 646-652).

 

(6) Miller W, Schuster SC, Welch AJ, et al. (July 2012). "Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change". Proc Natl Acad Sci U S A 109 (36): E2382–90.

 

(7) Lindqvist, Charlotte; Schuster, Stephan C.; Sun, Yazhou; Talbot, Sandra L.; Qi, Ji; Ratan, Aakrosh; Tomsho, Lynn P.; Kasson, Lindsay et al. (2010). "Complete mitochondrial genome of a Pleistocene jawbone unveils the origin of polar bear". Proceedings of the National Academy of Sciences 107 (11): 5053–5057.

Seeing the World through Other Eyes

I came across this little beauty this afternoon at Van Patten Woods:

Rainbow Bluet (Enallagma antennatum), Van Patten Woods FP, Lake Co, IL 6/21/2014

This is a female Rainbow Bluet, one of our prettiest damselflies. One of the neat thing about damselflies (and dragonflies) is their ability to navigate by polarized light. (1) Since polarization varies across the sky depending upon the sun's position, this is a very useful trick. Water reflects light in a polarized fashion as well, which is probably useful for a dragonfly as well. Other insects can do this as well:

Bibio albipennis, Lyons Woods FP, Lake Co, IL 6/2/2014

Golden Northern Bumblebee (Bombus fervidus), Gander Mt. FP, Lake Co, IL 8/3/2013

Many of them can also see ultraviolet light, which bees use to locate the appropriate flowers and the nectar within those flowers. (2) These guys have evolved strategies to take advantage of this ability:

Six-spotted Orbweaver (Araniella displicata), Ryerson FP, Lake Co, IL 5/31/2014

Orbweaver spiders place UV-reflective decorations within their webs to actually attract prey -- bait, if you will. (3)

When you're wondering what your favorite pet thinks about the world, it's worth remembering that he or she almost certainly doesn't perceive the world the way you do. So much of ecology would be completely hidden without the tools we have, based on theory hashed out by generations of physicists, built by engineers for those biologists with the imagination to conceive of a world that looks completely different than the one we see.

(1) Meyer, E. P., & Labhart, T. (1993). Morphological specializations of dorsal rim ommatidia in the compound eye of dragonflies and damselfies (Odonata). Cell and tissue research, 272(1), 17-22.

 

(2) Guldberg, L. D., & Atsatt, P. R. (1975). Frequency of reflection and absorption of ultraviolet light in flowering plants. American Midland Naturalist, 35-43.

 

(3) Craig, C. L., & Bernard, G. D. (1990). Insect attraction to ultraviolet-reflecting spider webs and web decorations. Ecology, 616-623.

 

 

Family Trees Revisited

Here's an interesting trio:

Edith's Checkerspot (Euphydryas editha), Flaming Gorge NRA, Daggett Co, UT 5/27/13

Steel-blue Cricket Hunter, (Chlorion aerarium), Illinois Beach SP, Lake Co, IL 8/2/2013

Red-bellied Snake (Storeria occipitomaculata), Lyons Woods FP, Lake Co, IL 3/5/2012

What's the link here? These are all illustrations of a common pattern in evolution. Not so many years ago, butterfly guides talked about 3 suborders of Lepidoptera -- moths, butterflies, and skippers. Similarly, Hymenopterans were split into three groups -- parasitic wasps, stinging wasps and bees, and sawflies. The squamate reptiles consisted of two -- the snakes, and the lizards. In each case, the assumption was that these groups had split apart early, and then each had diversified on its own.

Here's a rough cladogram, to give an idea:

Cladistic analysis, these days greatly enhanced by DNA analysis, has shown that this pattern doesn't often hold. Instead, what we see is early splits leading to "basal" groups that don't diversify much, (like several of the sawfly families and some "primitive" moths), a succession of further splits that don't do much, then one or two groups that split and apparently cross some sort of adaptive threshold, followed by an impressive radiation. So we find that the sawflies, for example, are actually not a natural group at all -- they're just those hymenopterans that didn't become wasps. Here's a more recent conception:

We find the same with Lepidopterans -- butterflies make up part of one suborder, along with most of our moths. Even within that suborder, most of the groups are moths, as are a large majority of the species. The old breakdown of moth, butterfly, skipper isn't tenable.

Even the snakes, clearly a natural group themselves, turn out to be nested within one of several suborders of lizards, long thought to be a separate group.

(A quick note on the use of scare quotes above -- these are two terms I cordially detest when used this way. A primitive species is one that died out a long time ago -- modern species have all been evolving since that early ur-ancestor. And a basal group, if you examine any cladogram that purports to show "the basal" species, is whichever lineage that emerged from that first split either without diversifying much, without becoming "interesting", or that has since lost most of its earlier diversity.)