Sunday, September 25, 2022

Book Review: Spiders of North America

It is “Spider Sunday” on this blog, so what better to post than a rave review of the newest spider identification resource, the Princeton Field Guide to Spiders of North America, by Sarah Rose. Yes, I wrote the foreword for this book, but I guarantee that this is an unbiased review. There is far more to recommend this book than my mere two cents at its beginning.

Spiders have faced an uphill battle in the widespread appreciation of these arachnids, in part due to few easily available, and easily affordable, resources for non-scientists. The most reasonably priced books are either outdated, full of errors such as mislabeled images, or both. Until now, the only current guides to spiders have been regional in nature (California and the Pacific coast, for example), or so expensive, and/or scientifically technical, as to discourage their purchase.

Finally, we have a true field guide, organized in a manner that respects the scientific terminology, and understands the limits of macrophotography, and facilitates the identification of many spiders by non-scholars.

One example of Rose’s innovative approaches is her color-coding of spider eyes. The eye arrangement of a given specimen is often key to its identification, but if you do not understand the jargon of “posterior median eyes,” or “anterior lateral eyes,” you are left spinning your wheels, if not throwing the book in the garbage. By associating the different pairs of eyes with different colors, it allows the user to make quick assessments of the creature they have in hand. The only drawback would come if you happen to be colorblind, and that is a consideration few, if any, publishers take into account.

Another way that the author organizes her book is by “guilds,” a term that in this case means the hunting lifestyle of the spider. Some spiders build two-dimensional sheet webs or orb webs, while others are “space web weavers” in three dimensions. Still others are ambush hunters or “ground active hunters.” This works well except maybe for mature male web-weaving spiders that leave their snares to look for mates, but the combinations of characteristics highlighted for each family of spiders overcomes those hurdles.

Each species entry in the book includes a range map, and verified state records. Our collective knowledge of spider distribution is relatively weak, and spiders excel at hitching rides on commerce and vehicles and other belongings, ending up far from their “normal” ranges, but here you have a good reference point for assessing the identity of most spiders you will encounter.

The images in the book are of living individuals, so all the colors and shapes are undistorted. Usually there is more than one image, to illustrate the dorsal (top) and ventral (underside) of the spider, and the color variations that the species might exhibit. Additionally, webs, egg sacs, and young spiders may be depicted, the better to demonstrate the full range of a species’ appearance and lifestyle.

The first part of this field guide provides an excellent overview of spider anatomy and biology, gives a brief and effective lesson in how spiders, and all organisms, are classified, and shares tips for observing spiders safely, ensuring that both you and the arachnid will be unharmed. Need to know the benefits of having spiders around? They’re in there. How do spiders fit into the larger picture of ecosystems? That information is also included. Did I mention there is an illustrated glossary in the back? Additional references are listed in the bibliography.

Before I end, I must offer an apology to all of you. This reference should have been available much sooner. I was the original author contracted to write this guide. It soon became apparent to me that I was not qualified to execute the project. Unfortunately, I procrastinated in disclosing that to the publisher. The least I could do was recommend a replacement, and I could not be more delighted that Sarah Rose agreed. This is a far better book than anything I could have written. If you have even a smidgen of curiosity about spiders, this reference will ignite it into a flame of passion. All the common species are in there, plus ones that you will see and say “Oh, I have got to find one of these!” Happy spider seeking, friends.

Tuesday, September 20, 2022

Fungus Party-y-y!

Sometimes, with luck, you stumble upon a wonderful circumstance of insect abundance. My partner, Heidi, did so this past Saturday afternoon, September 17, along a trail through Wyandotte County Lake Park, Kansas, USA. She happened to notice a thick mass of mushrooms at the base of a tree. It was literally crawling with insects.

Everybody on the dance floor!

The fungus in question may be a species of “oyster mushroom” in the genus Pleurotus, according to Ben Sikes at the University of Kansas, and with the Kansas Biological Survey. He was kind enough to offer an opinion on my photo of it on iNaturalist. At least some species are fit for human consumption, too, but please do not forage without expert guidance, at least initially. Your experiment in wild culinary arts could end abruptly and permanently if you do not know exactly which mycological fruiting bodies to avoid.

"Get down to it....get down to it...."

Insects, on the other hand, do not seem to care, especially the many varieties of beetles that are collectively known as fungus beetles. There are pleasing fungus beetles (family Erotylidae). There are handsome fungus beetles (Endomychidae), hairy fungus beetles (Mycetophagidae), tooth-necked fungus beetles (Derodontidae), silken fungus beetles (Cryptophagidae), polypore fungus beetles (Tetratomidae), cryptic fungus beetles (Archeocrypticidae), minute tree-fungus beetles (Ciidae), and several genera of darkling beetles (Tenebrionidae) that are found almost exclusively on or in fungi, including woody shelf fungi. I may be forgetting some….

Triplax thoracica, but there may have been another species with a dusky or black belly instead of an orange underside.

The most abundant insect on this particular mushroom cluster is probably a pleasing fungus beetle, Triplax thoracica. That genus, certainly, but that species apparently loves oyster mushrooms. It occurs across the eastern half of the U.S. and adjacent Canada. At only 3-5.6 millimeters in length, they are difficult to spot as individuals, but there were dozens flying in, flying out, and running about.

Uh, oh [abrupt, scratched record sound].

In a prehistoric analogy, Triplax are the herd of plant feeders. Sure enough, there were vicious carnivores prowling through the gills and over the caps of the mushrooms.

Sharp dresser, anyway.

A sleek, serpentine, black rove beetle with metallic blue-green elytra (wing covers) popped into view periodically. Meet Philonthus caeruleipennis, 12-15 millimeters long. Were it a vertebrate, it would no doubt be a weasel, mink, ferret, or other mustelid. It is transcontinental in Canada, but occurs only in the northeast quarter of the U.S. It also occurs in Europe.

Pull the fire alarm! Call 9-1-1!

The equivalent of Tyranosaurus rex in this micro-scenario would be the Brown Rove Beetle, Platydracus maculosus. Measuring 22-35 millimeters, it dwarfs its prey, which in this case was the Triplax fungus beetles.

Serial killer making mincemeat of partygoers.

By now, oblivious to the monsters among them, the Triplax party was becoming something of an orgy, with love trains of males following females. It was quite amusing.

Gettin' busy.

Some of the fungus beetles also had passengers in the form of phoretic mites. The mites, which are probably “mesostigs” in the order Mesostigmata, cause no harm to the beetles. Instead of being parasitic, the mites are hitchhikers, using the beetles as transport to a location where they can feed on insect eggs or other tiny prey.

Mites being a little voyeuristic....

Along with the beetles were pomace flies, family Drosophilidae. These are the “fruit flies” you see in your kitchen around overripe fruit, fermented beverages, and other foods. Drosophilids sare surprisingly diverse, and a good variety can be found around rotting fungi “in the wild.”

Pomace fly disappointed that the mushroom is not spoiling already....

The latecomer to the party was a worker Tennessee Spine-waisted Ant, Aphaenogaster tennesseensis. She was simply looking for dead or injured insects she could take back to her colony to feed her larval sisters.

"Just passing through!

At last, it was time for me to say farewell. Heidi had already progressed down the trail by about fifty yards.

"I'm blowin' this fruit stand!"

Now is a perfect time to go out looking for mushrooms and their associated insects. We left these mushrooms alone, but sometimes it is necessary to tear apart the fungus to find insects. It is best to do so over a white enamel pan, or some other kind of tray so that it catches the insects falling out. Be quick to grab the rove beetles before they take flight. If you do know your mushrooms, then bonus! You can take uninfested specimens to the kitchen instead of the lab. Enjoy your autumn no matter what you do.

Nom-nom-nom-nom....

Sources: Rhine, Lyndzee. 2020. A Pocket Guide to Common Kansas Mushrooms. Wichita: Great Plains Nature Center. 69 pp.
Evans, Arthur V. 2014. Beetles of Eastern North America. Princeton, New Jersey: Princeton University Press. 560 pp.

Wednesday, August 31, 2022

Wasp Wednesday: Another Cricket Hunter, Lyroda subita

Crickets in the family Gryllidae are sufficiently diverse, and abundant enough, to be the target hosts for a variety of parasitoid wasps, especially those in the families Sphecidae and Crabronidae. There are previous posts about the Steel Blue Cricket Hunter, and the genus Liris, but here in eastern Kansas there is another player. Lyroda subita is easily confused with Liris, but the clue is in the "toes."

Like all of the larger cricket-hunting wasps, Lyroda is solitary, each female constructing her own nest, in this case an underground burrow. Whether she digs it herself is the subject of debate. At least some observations indicate the wasps use the abandoned burrows of other solitary wasps rather than excavating a nest themselves. The tunnel of Lyroda subita can be fifteen to thirty centimeters below the surface of the ground. There may be only one cell, or two. Historical records are rather scant.

The female hunts almost exclusively crickets of the family Gryllidae, both adults and immatures (nymphs). She subdues her quarry with a paralyzing sting in a nerve center that renders the victim limp. Transporting such a bulky insect is no problem for the agile wasp. She slings it beneath herself, grasps the cricket's antennae in her mandibles, and away she goes. She can run over the ground with it, but can also glide or even fly with it. Multiple crickets are used to provision a single cell, after which she lays an egg on the last cricket, seals the cell, and then repeats the entire process.

There is at least one record of L. subita using a different host: a pygmy mole cricket of the family Tridactylidae. Since these are mostly subterranean orthopterans, and not that closely related to crickets, the how and why of this anomaly remains unanswered. Other species of Lyroda from other parts of the world are known to use pygmy grasshoppers, family Tetrigidae, as hosts, and those insects occupy similar micro-habitats as pygmy mole crickets. Maybe it is a matter of what is available in a given habitat, then. Pygmy mole crickets and pygmy grasshoppers occur mostly in wet or damp situations along stream banks.

In our Leavenworth, Kansas yard, there are large numbers of Gryllus field crickets, and ground crickets of the subfamily Nemobiinae, offering Lyroda plenty of options.

L. subita is a medium-sized insect. Females range from 10-13 millimeters in body length, males slightly smaller at 6-10 millimeters. Both sexes are slate gray in color with silver highlights, especially on the abdomen. In the right light it can appear the abdomen is banded in dark gray and white. The ocelli, a trio of simple eyes on the crown of the head, between the compound eyes, are present. The most easily observed feature is on each "foot." The last tarsal segment bears a very large pad called an arolium (plural arolia), which differs markedly from the petite feet of the nearly identical Liris genus. Liris also has only a single mid-ocellus, the lateral simple eyes being reduced to longitudinal scars.

This species occurs throughout most of the United States (except for Washington, Oregon and the southwest states), southern Canada, the northern half of Mexico, and also Cuba and Hispaniola. There are twenty-one other species of Lyroda, most of which are found in southeast Asia, plus Africa, Australia, and South America.

Sources: Kurczewski, Frank E., and Margery G. Spofford. 1985. "A New Host Family for Lyroda subita (Hymenoptera: Sphecidae)," The Great Lakes Entomologist 18(3): 113-114.
Bohart, R.M. and A.S. Menke. 1976. Sphecid Wasps of the World: A Generic Revision. Berkeley: University of California Press. 695 pp.
Elliott, Lynette, et al. 2006. "Species Lyroda subita," Bugguide.net
Khvir, Viktor I., and Wojciech J. Pulawski. 2020. "A Revision of New World Lyroda Say, 1837 (Hymenoptera: Crabronidae)," Proceedings of the California Academy of Sciences Series 4, Volume 66, nol 13: 315-330.

Wednesday, August 17, 2022

Wasp Wednesday: Aulacids

Pristaulacus fasciatus female

Sometimes an unfortunate event yields something interesting later. More on that in a minute. Aulacid wasps are seldom seen, but also often overlooked due to their superficial resemblance to ichneumon wasps. They are found in similar situations as ichneumons, and behave similarly. Two genera and 185 species make up the family Aulacidae, and they collectively occur on all continents except Antarctica. There are thirty-two species in North America.

At 3 AM on June 1, 2022, a massive limb broke off of the Pin Oak tree in our front yard in Leavenworth, Kansas, USA. It apparently hit the ground before striking our house, but it did enough damage to require a new roof and gutters. Removal of the limb took place later that day, and I had the service that did the work leave the log sections in a pile around the base of the tree, where they sit currently. The least I could get out of this minor tragedy would be some interesting insects.

A female Chrysobothris sp. jewel beetle. Her larval offspring are potential hosts for aulacids.

Cut, living wood emits aromatic compounds that attract insects eager to exploit the resource. These include wood-boring beetles in the families Cerambycidae (longhorned beetles), and Buprestidae (jewel beetles or metallic wood-boring beetles) that lay their eggs in bark crevices. The beetle larvae that hatch then bore into the wood. In turn, the parasitoids of these beetles arrive. Aulacid wasps are known to be parasitoids of these beetles, especially the larvae of the longhorned beetles, as well as larval wood wasps in the family Xiphydriidae.

Another potential host for aulacids: Graphisurus fasciatus, a longhorned beetle.

I had collected aulacids in Cincinnati, Ohio when I lived there, and those specimens now reside with the rest of my collection at the Denver Museum of Nature and Science. I had not photographed any, except for one specimen of Pristaulacus rufitarsis in Colorado. I had the good fortune of getting permission to look for insects at a slash pile of freshly-cut pine in Black Forest, just north of Colorado Springs.

Pristaulacus rufitarsis female in Colorado, USA

Here in Kansas, on the western-most fringe of the eastern deciduous forest, I was not sure whether these wasps would occur here. I was delighted to finally spot a female of Pristaulacus fasciatus on the pile of logs in our front yard in late July. Since then, through mid-August, I have seen at least three specimens, and finally managed to get respectable images. All have been females. Perhaps mating takes place away from the logs and trees that the females scour for evidence of their intended hosts.

It has been interesting observing these wasps. They walk haltingly across the logs, bobbing their abdomens slightly, and slowly rowing their wings, which is enough to give one cause to think they might be stinging spider wasps. Indeed, Pristaulacus fasciatus may be part of a small mimicry ring, which I’ll address in a future post.

I notice that the female wasp probes every crack and crevice by inserting her antennae deeply into it, perhaps divining the location of a host that way. Once she locates a victim, she commences ovipositing. Grooves on the inner surface of her hind coxae (basal-most segments, connected directly to her thorax, help guide and stabilize her thin ovipositor as she inserts it.

Her ovipositor is entering the wood between her hind leg and middle leg.

Aulacids are identified by the attachment of the abdomen high on the thorax, a short “neck” behind the head, and a somewhat sinuous, not straight, ovipositor. The first two characters reveal the relationship of aulacids to ensign wasps and carrot wasps under the umbrella superfamily Evanoidea. Aulacus is the other genus, with species typically a bit smaller than Pristaulacus. Females of P. fasciatus have a body length averaging around 16 millimeters, while males are slightly smaller at 13 millimeters. They are conspicuous insects, easily spotted but only in these unusual situations.

Look for P. fasciatus from eastern Texas and Nebraska eastward, though it appears absent from most of the southeast U.S. and Canada. There is one record in New Mexico on iNaturalist.

Sources: Eaton, Eric R. 2021. Wasps: The Astonishing Diversity of a Misunderstood Insect. Princeton, NJ: Princeton University Press. 256 pp.
Smith, David R. 1996. “Aulacidae (Hymenoptera) in the Mid-Atlantic States, With a Key to Species of Eastern North America,” Proc. Entomol. Soc. Wash. 98(2): 274-291.