Spider Sunday: Top Spider Hoaxes, Urban Legends, and Myths

I swear, sometimes I feel the “Spider Sunday” feature on my blog is a completely useless exercise. There are so many recurring hoaxes and urban legends about spiders that raise their ugly heads again and again and again,…now spread even faster through social media! Thank you so much, Facebook. Please feel free to share this post the next time you see an idiotic spider hoax surface. Here is my list of the worst of them, in no particular order.

Lethal spider species lurks under toilet seats. What anyone would have against the lovely and completely harmless Two-striped Jumping Spider Telamonia dimidiata is beyond me, but it is the chosen villain in a sinister campaign to scare everyone off of toilet seats in airports around the world. The original version blamed the non-existent Arachnius gluteus spider. The name alone should have tipped people off as to the authenticity of the reports (and made wise people smile and chuckle).

Daddy Long-legs (Harvestman)

Daddy long-legs are the most venomous spiders, but they can’t bite people. First of all, “daddy long-legs” are not even spiders. They are arachnids, but in the order Opiliones and more properly called “harvestmen.” They are not venomous at all, and are mostly scavengers and opportunistic predators on weakened insects.

The average human swallows “x” number of spiders per year in their sleep. This is complete bunk (but I did once wake up with a dead German Cockroach in my mouth).

Somebody’s houseplant cactus explodes, liberating baby tarantulas. Really? Tarantula mothers don’t stick their eggs in cacti. They carefully wrap them up in a silken sac and guard them tenaciously at the bottom of their burrows. Once the eggs hatch, the female continues to guard them until their next molt, at which time they disperse.

Baby Tarantula

The “Hobo Spider” is dangerously venomous. This is false, but also an enduring mystery. Tegenaria agrestis is native to Europe where it is most certainly harmless. Individual spiders from populations introduced in the U.S. have been implicated in necrotic wounds. One plausible theory is that victims of spider bites (or other puncture wounds wrongly attributed to spiders) have developed secondary bacterial infections. Stay tuned for further developments.

The above are just the tip of the proverbial iceberg, of course. A more complete listing can be found on Rod Crawford’s Spider Myths Page. When in doubt yourself, you can also consult Snopes.com, or one of the other websites cited in this article from TechRepublic.com.

Thank you for your attention, we now end this rant and return you to your regularly-scheduled programming of truth, fascination, and beauty.

Happy Holidays!

I want to wish all of my followers and fellow bloggers Happy Holidays, and my sincerest best wishes to you for a bright new year.

I spent yesterday doing a Christmas bird count in the vicinity of La Veta, Colorado (Spanish Peaks area), where we were rewarded with spottings of wild turkey (the bird, silly, not the whiskey), and a Golden Eagle among several other species. Interestingly, I learned that Eastern Boxelder Bugs (Boisea trivittata) are called "adobe bugs" there. Never heard of that before. That insect was quite plentiful, though, basking on the south side of houses despite the lingering snow at over 7,000 feet elevation.

I continue to enjoy making new discoveries like that, and then sharing them with all of you. Remember there will be more diversity in posts next year. Remember, too, that you are always welcome to share your own questions, images, and observations with me. My personal universe is rather small, but together we can broaden our collective horizons. Thank you.

BugEric24ATyahooDOTcom.

Wasp Wednesday: Not Wasp IX

I have recently begun participating in “Project Noah,” and as a result find yet another demand for identification of mystery bugs, like this one posted just yesterday. The subject of the image is a Red-necked Ash Borer, Neoclytus acuminatus, a type of longhorned beetle in the family Cerambycidae.

The person who posted the image says he calls them “crickabees” because they have “legs like a cricket….and stripes like a bee.” Most folks mistake these beetles for wasps, though. They can be fast-moving insects, a trait not always associated with beetles. Couple that with their bold markings, and it would be easy to assume they are a stinging insect.

Despite its name, this beetle bores in virtually any hardwood tree during its larval stage, though it does seem to favor ash. It has also been recorded from woody vines and shrubs. I have noticed the adults on freshly-cut trees, but also on older logs. While dead, dying, or weakened trees are most commonly exploited by the Red-headed Ash Borer, it is also a serious pest of healthy black locust trees planted as windbreaks or on farm woodlots. It may also attack recently-planted trees. So, trees stressed in some way are going to be vulnerable to this beetle.

References indicate that the normal flight period for Neoclytus acuminatus is between May and August in the northeast U.S., and from February to November in the southeast. There may be up to three generations each year in the south, usually only one in the north. Firewood brought indoors in late winter or early spring may yield adult beetles emerging inside your home.

This species is widespread, found almost everywhere east of the Rocky Mountains (and into Idaho). It is not one of the larger longhorned beetles, adults measuring only 4-18 millimeters in length.

Sources: Shour, Mark. 2008. “Red-headed Ash Borer Also a Threat to Ash Trees,” Extension News.
Solomon, J.D. 1995. Guide to Insect Borers of North American Broadleaf Trees and Shrubs. Agric. Handbk. 706. Washington, DC: U.S. Department of Agriculture, Forest Service. 735 pp.
Yanega, Douglas. 1996. Field Guide to Northeastern Longhorned Beetles (Coleoptera: Cerambycidae). Illinois Natural History Survey Manual 6. 184 pp.

Spider Sunday: Difoliate Orbweaver

Some spiders are almost a complete mystery. They might have a species name, but that does not mean that much is known about their biology or life history. Such is the case with the Difoliate Orbweaver, Acacesia hamata.

This image represents the only specimen I have ever seen, encountered at the Lynx Prairie Preserve in Adams County, Ohio on the morning of August 26, 2011. The species is recognized by the very distinctive pattern on the abdomen. “Difoliate” translates to “two foliums,” a reference to the dagger-like (“cardiac”) mark inside the wider wedge-shaped marking. The roughly triangular or wedge pattern with wavy borders that decorates many orb weavers is called a “folium.”

This orbweaver is of average size, mature females measuring 4.7-9.1 millimeters in body length, males 3.6-5 millimeters. The basic color varies from greenish gray to brown on the legs and carapace, and gray to green on the abdomen. Resting spiders often adopt the pose shown in the image above.

We know that Acacesia hamata is the only species of its genus found north of Mexico. The other five species collectively range from Mexico to Argentina, and are known from only a handful of specimens. A. hamata occurs from New England to Florida and west to Illinois and Texas.

The female I found was on a blade of tall grass in what amounts to a glade: a slice of prairie surrounded by deciduous woodlands. Other scientists have found this species by sweeping grasses in open fields, suggesting this spider prefers this kind of habitat. One other reference lists it as occurring in bushes and shaded woods (Kaston, 1978).

A more recent book describes it building its orb web only at night, taking it down before daybreak. Females startled by bright lights are capable of deconstructing their snare in under sixty seconds. The spider does this by strategically cutting support lines and eating the silk as it rolls up the web beneath it. A complete web is a vertical orb 20-25 centimeters across, strung three to four feet (one meter) above the ground in shrubs. Populations may be fairly dense, but the spider is only locally common (Howell & Jenkins, 2004). Mature individuals are found in early summer or mid-summer.

We still know nothing of the reproductive behavior of this species, or what the egg sac looks like. Does this species prefer one kind of insect as prey? Many such questions remain unanswered.

Try finding Acacesia hamata if you live within its geographic range. Look along forest edges, the ecotone where woods meet meadows, fields, and prairies.

Sources: Fitch, Henry S. 1963. Spiders of the University of Kansas Natural History Reservation and Rockefeller Experimental Tract. Lawrence, KS: University of Kansas Museum of Natural History. 202 pp.
Gaddy, L.L. 2009. Spiders of the Carolinas. Duluth, MN: Kollath+Stensaas Publishing. 208 pp.
Glueck, Susan. 1994. “A taxonomic revision of the orb weaver genus Acacesia (Araneae: Araneidae),” Psyche 101: 59-84.
Howell, W. Mike an Ronald L. Jenkins. 2004. Spiders of the Eastern United States: A Photographic Guide. Boston: Pearson Education. 362 pp.
Kaston, B.J. 1978. How to Know the Spiders. Dubuque, IA: Wm. C. Brown Company Publishers. 272 pp.
Moulder, Bennett. 1992. “A Guide to the Common Spiders of Illinois,” Illinois State Museum Popular Science Series, Vol. X: 1-125.

Wasp Wednesday: Pseudomalus auratus

At this time of year, we decorate the inside of our homes with festive ornaments, many of them green or gold or red. Nature offers her own ornamental organisms, but many are too small to grab our attention unless we look closely. Such is the case for the brilliant little cuckoo wasp, Pseudomalus auratus.

Cuckoo wasps in general are also known as “jewel wasps,” so colorful are they. This particular little gem averages only four millimeters in length, so despite its contrasting colors of emerald (head and thorax) and ruby red (abdomen), Pseudomalus auratus is easily overlooked. Rarely does this wasp visit flowers, either, so you have to seek it out elsewhere.

This species is not native to North America, but is common throughout Europe, Asia, and northern Africa. It was likely introduced here accidentally prior to 1828. Until fairly recently, records in the U.S. were limited to the Atlantic seaboard, but now it may turn up almost anywhere.

Larvae of this wasp are kleptoparasites in the nests of other solitary wasps, and solitary bees, that nest inside hollow twigs, pre-existing cavities in wood, and similar situations. Known hosts include the smaller wasps in the family Crabronidae, and bees in the genera Ceratina (small carpenter bees, family Apidae), Hylaeus (masked bees, family Colletidae), and Anthidium (wool-carder or cotton bees, family Megachilidae). The cuckoo wasp grub feeds on the provisions stored by the mother of the host larva. They literally steal the meal provided by the host for its offspring.

Pseudomalus auratus is not without its own enemies. Parasitic wasps in the families Ichneumonidae and Torymidae are known to kill the larvae, though those casualties might be the result of the parasites attacking the same host as the cuckoo wasp.

Look for adults of the cuckoo wasp around aphid colonies and extrafloral nectaries on various plants. I found specimens in Ohio at aphid colonies on Honeyvine Milkweed (Ampelamus albidus) and Northern Catalpa (Catalpa speciosa). The specimen shown here is from Colorado Springs, found sipping on the tacky exudates of Common Sunflower (Helianthus annuus).

Please share your own observations of this species with the scientific community. Our understanding of the distribution and hosts for Pseudomalus auratus in North America is in its infancy.

Sources: Agnoli G.L. & Rosa P., 2012 : Pseudomalus auratus (Linnaeus, 1758) . In: Chrysis.net Database of the Italian Chrysididae, interim version 12 December 2012.
Species page at Discoverlife.org.
Species page on Encyclopedia of Life.
Bohart, R.M. and Lynn S. Kimsey. 1982. “A Synopsis of the Chrysididae in America North of Mexico,” Mem. Am. Entomol. Inst. 33: 1-266 (Note: species is listed as Omalus auratus).

Big Changes Coming Here

I can hardly believe I have been at this for three years and over 300 posts, but that is how it should be. When you enjoy what you are doing, time flies. Time has come to make some changes, though, all for the better I think.

There will be more diversity in the subjects covered here. I will likely be adding “Moth Monday,” “True Bug Tuesday,” and “Fly Day Friday” to the current “Wasp Wednesday” and “Spider Sunday.” “Orthoptera Thursday” is another possibility. You won’t get one of each every week, but you’ll probably get at least two posts each week.

Posts will probably be shorter. I need to expand my audience, and most people do not read online, they scan. They like bullet points. I will do my best to balance thoroughness and storyline with brevity.

I will be debuting a new website. I am privileged to be working with a good friend who is also a website developer to make BugEric dot com a reality, probably sometime in January or February of 2013. Blog posts will likely be moved there, and this site kept as an archive. The new site will offer me far more flexibility in what else I can do, including making products available for sale.

The most important thing I need to do, however, is to promote my name and my site to generate some kind of income. Yes, I could get a “regular job,” but then most of what you are getting would cease to be due to time constraints. Please help me to do this, if you will, through continued donations, recruitment of advertisers, and whatever other avenues you can think of. My expertise is in writing and entomology, not in internet marketing.

I thank you for your continued support through following this blog, and look forward to bringing you an even better product in the future.

Spider Sunday: Nursery Web Spider

If Spiders.us had a top ten list for the spider species we are asked to identify most often, then the nursery web spider, Pisaurina mira, would certainly be on it. This is a large, abundant spider, especially in New England where there are lots of people who see it.

This species also reaches adulthood in the spring, just when people are going out into their yards and gardens. You could not be blamed if you encountered one unexpectedly and decided you’d had enough of this outdoor stuff for the rest of the year. Female Pisaurina mira measure from 12.5-16.5 millimeters in body length, males 10.5-15 millimeters. They are “leggy,” too, so that makes them look larger still (35-45 mm legspan).

Members of the family Pisauridae are collectively known as “nursery web spiders” because of the habit of the female suspending her egg sac in a tangled web just prior to the spiderlings emerging. The mother spider guards both the sac and the spiderlings that hatch, until they molt once more and disperse. This web envelopes a small section of foliage, usually well off the ground in weeds or a shrub.

Pisaurina mira is a hunting spider that otherwise spins no web, or at most minimal “scaffolding” where it sits motionless in ambush on foliage during the day and/or night. They may also hunt actively, sometimes visiting outdoor lights to catch the many insects attracted to the artificial beacons. Despite their small eyes, they are superior at detecting motion, responding quickly to potential prey, or fleeing from perceived danger.

Recognizing this spider is not always easy. Most mature individuals are light brown, beige, or grayish with a broad, dark stripe down the entire length of their body. Immature specimens, and some adults, lack the distinct stripe, however. The spider often rests with the first two pairs of legs held tightly together.

Mating takes place in mid-summer. The male employs a silken “veil” to bind the first and second pairs of legs of his mate whilst they are both suspended from draglines. Each mated female prepares an egg sac, carting the white sphere in her jaws.

© Michelle Lynn St. Sauveur via Bugguide.net

She eventually finds a suitable place to hide her egg sac, such as beneath a folded leaf, and shrouds the whole thing in her nursery web. Her young are the arachnid equivalent of teenagers by autumn, and they seek a snug place to overwinter. Inside cracks and crevices, and beneath loose bark or stones are good places to find them.

Despite their intimidating size, nursery web spiders are not considered to be dangerously venomous to people or pets. To the contrary, they are highly beneficial predators of insect pests in your yard, garden, farm or orchard. The species ranges from southern Ontario and Quebec in Canada to Florida, west to Minnesota, Nebraska, Kansas, Oklahoma, and the Rio Grande Valley of Texas. Look along forest edges in the understory, among grapevines, and on weeds in open fields.

They can be mistaken for wolf spiders at first glance, but are much more likely to be found in the vertical plane rather than on the ground. The eye arrangement differs between the two as well. Pisaurina has all eyes basically the same size.

Sources: Bruce, John A. and James E. Carico. 1988. “Silk use during mating in Pisaurina mira (Walckenaer) (Araneae, Pisauridae),” J. Arachnol. 16: 1-4.
Carico, James E. 1972. “The Nearctic Spider Genus Pisaurina (Pisauridae),” Psyche 79: 295-310.

Wasp Wednesday: Polistes exclamans

Paper wasps in the genus Polistes are more diverse the farther south you go, reaching their zenith in tropical and subtropical climates. Global climate change may be nudging some species farther north, though, so it pays to keep your eyes open. One species that naturally ranges beyond the subtropics is the Common Paper Wasp, or “Guinea Wasp,” Polistes exclamans.

I recommend using the scientific name, as there is no official common English name. This is a widespread insect found from New Jersey south and west to Florida, Indiana, Illinois, Nebraska, Colorado, Arizona, and southern California. It also ranges into Mexico, and has been introduced to Hawaii; and there is one record for Ontario, Canada.

Look for their nests in sheltered places, such as beneath the eaves of homes. They will also nest in trees, but most of the time that I have found nests, they have been attached to some man-made structure. Here is one from beneath an interpretive sign on the hawk watch platform at Cape May Point State Park in New Jersey (October 17, 2010).

Here is another nest on the ceiling of a picnic shelter in the same park (October 3, 2012).

This is a fairly easy species to identify:

• Evenly patterned in red and yellow, usually with black coloration reduced to thin bands on abdomen (occasionally more extensive black markings, especially on top of thorax).
• Antennae banded with red, black, and yellow (most paper wasp species have antennae of one color).
• Size relatively small (forewing length 12-16.5 millimeters).

Like most paper wasps, this species preys on caterpillars that the worker wasps chew up and feed to the larvae in the nest. They feed on a wide variety of moth and butterfly caterpillars, including members of these families: Pieridae (white and sulphur butterflies), Hesperiidae (skippers), Noctuidae (owlet and tiger moths), Notodontidae (prominent moths), Sphingidae (sphinx moths or hawk moths), and Saturniidae (giant silkmoths).

You would think that social wasps in general would not be bothered by predators and parasites given the presence of many stinging adult wasps ready to defend the brood (eggs, larvae, and pupae), but such is not the case. Polistes exclamans can occasionally lose its entire brood to bird predation. The acrobat ant, Crematogaster laeviuscula can also destroy a nest. Partial losses can come from Elasmus polistis, a tiny wasp in the family Eulophidae that infests young paper wasp nests that are defenseless while the foundress is away foraging.

Note males on right have black on thorax and head

Irony of ironies, caterpillars of the pyralid moth Chalcoela iphitalis can take a toll due to their parasitic activities on the wasp larvae. The moths themselves are quite attractive:

This is one of the most studied of social wasps, and the literature cited below is only a fraction of the scholarly works devoted to P. exclamans. Despite this, the known distribution of the species has been clarified mostly through documentation by citizen scientists contributing their specimens and images to universities, museums, and websites like Bugguide.net that are monitored by professional entomologists. Keep up the good work, folks.

Sources: Buck, Matthias, Stephen A. Marshall, and D.K.B. Cheung. 2008. “Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region,” Canadian Journal of Arthropod Identification No. 5, 492 pp. (PDF version)
Starr, C.K. 1976. “Nest reutilization by Polistes metricus (Hymenoptera: Vespidae) and possible limitation of multiple foundress associations by parasitoids,” J. Kans. Entomol. Soc. 49(1): 142-144.
Strassmann, Joan E. 1981. “Parasitoids, Predators, and Group Size in the Paper Wasp Polistes Exclamans,” Ecology 62(5): 1225-1233.

Spider Sunday: Cave Orbweaver

One of the oddballs of the family Tetragnathidae is the Cave Orbweaver, Meta ovalis. It does not have the exaggerated jaws, long legs, or elongated body typical of most other long-jawed orb weavers. It even spins a vertical orb web, in contrast to the usual horizontal webs made by other tetragnathids.

Meta ovalis has also gone by the name Meta menardi, but it has been determined that M. menardi is a separate species found only in Europe and Asia (to Korea).

This is an average-sized spider for orb weavers, females measuring 8-10 millimeters in body length an males averaging 9.5 millimeters. The species ranges from southeast Canada to Georgia and west to the Mississippi River, especially along the Appalachian Mountains and the Ozark Plateau. It is one of two North American species in the genus, the other being found only in California.

The typical habitat for cave orb weavers is, surprise, surprise, caves, abandoned mines, old wells, basements, and densely-shaded ravines. That is why I found this specimen on the exterior of a building, in broad daylight, in New Hampshire, on October 11, 2009. Since it was not associated with an obvious orb web, my first thought was that it was a sheetweb weaver in the family Linyphiidae, or maybe a cobweb weaver in the family Theridiidae. The spiny legs ruled out cobweb weavers, but I was still mystified.

I collected the specimen and took it to the lab I was using at University of Massachusetts, Amherst, where I took the two images on the table. Fortunately, I had access to good references and was able to eventually identify it correctly.

This is not a true cave inhabitant in the sense that it dwells only in the entrances and twilight zones of caves, and not in the deep recesses. It has obvious eyes, and is fully pigmented. These characteristics classify it as a “troglophile” rather than a troglobite. The webs are usually built from the ceiling of a given location, especially in protected situations (termed “kettles” and “bells” on the ceiling of caves) where dessicating air currents can’t dry them to death. The spider seems to prefer sitting near the edge of the web rather than its center, but frankly, little research and observations have been done on cave orb weavers.

One exception to the dearth of studies is Meghan Rector’s thesis, cited below. She discovered that immature specimens of the cave orb weaver may be distributed slightly deeper in caves, and construct larger webs to increase the potential for the capture of more scarce prey.

Clearly, more work is needed just to determine the geographic range of this species. Fauna of caverns in general is poorly known, and often endemic to a single cave or cave system. Spelunking, anyone?

Sources: Slay, Michael E., Daniel W. Fong, and Mark D. Kottmyer. 2009. “Meta ovalis (Araneae: Tetragnathidae) observed preying on a troglobiotic milliped, Causeyella (Chordeumatida: Trichopetalidae),” Speleobiology Notes 1: 3-5.
Rector, Meghan Anne. 2009. “Foraging in the Cave Environment: The Ecology of the Cave Spider Meta ovalis (Araneae: Tetragnathidae). Master of Science Thesis. 113 pp.
Reeves, Will K., John B. Jensen, and James C. Ozier. 2000. “New faunal and fungal records from caves in Georgia, USA,” J. Cave Karst Stud. 62(3): 169-179.
Yoder, Jay A., Joshua B. Benoit, et al. 2009. “Entomopathogenic fungi carried by the cave orb weaver spider, Meta ovalis (Araneae, Tetragnathidae), with implications for mycoflora transfer to cave crickets,” J. Cave Karst Stud. 71(2): 116-120.

Holiday Gift Guide 2012

At this time of year I like to give a free plug to products that I have found useful myself, or that I believe would be beneficial to my readers and their friends. This year has seen a trio of books that I am proud to sing praises of. I even lent images and text to one of them. Enjoy!

Kollath+Stensaas Publishing continues to turn out highly useful, generously illustrated, and compact regional field guides on subjects seldom treated by major publishing houses. The latest from their presses is Insects of New England & New York, by Tom Murray.

Tom is a prolific photographer of invertebrates and his images here are more than worth the $18.95 retail price of the book. I was profoundly flattered to receive a free copy, but even more astounded to read the acknowledgements:

”When I was first becoming serious about insect photography, Eric Eaton….would regularly visit my website and identify my photos. With Eric’s encouragement I joined www.Bugguide.net in March of 2005.”

Tom should be very proud of what he has done with that “encouragement.” Critics will say that the images of insects identified to species, or even genus, can be misleading to users trying to make their own identifications. This is true, because many species look essentially identical, or are conversely highly variable in color, pattern, and/or size. I would make the counter argument that one goal of a field guide should be to illustrate just how incredibly diverse invertebrates are. Tom and the publishers achieve this in boatloads.

Insects of New England & New York is more comprehensive than most field guides to insects for any region. It should be a standard reference for students of all ages throughout the northeast U.S. and adjacent southern Canada. Still can’t get enough of Tom’s photography? Then please visit his amazing galleries at pbase.com.

Another good friend, who I have yet to meet in person, had her own book come out this year. Seabrooke Leckie, together with David Beadle, produced the Peterson Field Guide to Moths of Northeastern North America (Houghton Mifflin Company).

Seabrooke lives in the wilds of Canada, assuring that any U.S. bias was curbed at least to some degree in the coverage of this book. Those that are familiar with Charles Covell’s A Field Guide to Moths of Eastern North America (Houghton Mifflin Company, 1984), also in the Peterson series, might think this new book to be redundant at best. Not true. Beadle and Leckie cover more species, and illustrate them with images of live specimens. No more pinned specimens with wings spread out. What you see at your porch light is what you will see in this book. Common variations in color and pattern are also shown for those species that vary in their appearance.

This book exceeded my expectations. One thing you might find puzzling, as I did, are the green, red, and orange bars next to the name of each species. Those bars represent “spring,” “summer,” and “fall” respectively. Beneath the bars is a black line that is not readily apparent, but which indicates the flight period for that species. This is explained in the “how to use this book” chapter, but it could have benefitted from a diagram. That is a minor negative, completely overwhelmed by the quality and comprehensiveness of this guide.

Seabrooke is a very gifted writer, and one’s style can be cramped by the constraints imposed by field guides. You owe it to yourself to visit her blog, The Marvelous in Nature, for a dose of her engaging style.

Last, but not least, Kenn and Kimberly Kaufman have another hit in the Kaufman Field Guide series with the Kaufman Field Guide to Nature of New England (Houghton Mifflin Company). Kenn was kind enough to approach me to contribute the terrestrial invertebrate section, both text and a few images, for which I was very grateful. Income never hurts, but it is always a joy to work with him on a new project.

Again, this book far exceeded my expectations, even though I should have known better. Yes, virtually every organism you are likely to encounter, plus geology, weather, and astronomy are covered in this book. From your backyard to the wilderness, it’s in there. Tidepool life, and open ocean fishes are even included. Wait, there’s more! You also get….passages on habitats, sustainability, endangered species, conservation, and invasive species. Now how much would you pay? Ahem. Sorry, I was momentarily channeling infomercials.

I am certain it is not coincidental that all three of these books are focused on New England or the northeast U.S. It makes sense for the publisher, as this is where the majority of the human population lives, recreates, and does business. I look forward to participating in the creation of more regional guides in the future. Breaking our biosphere down into bite-size regions means that you can cover more species.

There you have it, the three books that I think every naturalist should have on their shelves this year. Let me know your opinions, and feel free to make additional suggestions.

Wasp Wednesday: Carrot Wasps

Around the holidays, we humans tend to pack on the pounds as we indulge in feasts and parties at Thanksgiving and Christmas. Wasps do not have this problem. One family of wasps in particular manages to stay super-slim and slender: the Gasteruptiidae or “carrot wasps.”

There are at least fifteen species of carrot wasps in North America, all in the genus Gasteruption. Five of those occur in the eastern U.S. and Canada. At first glance, they might be mistaken for ichneumon wasps, or even sphecid wasps in the genus Ammophila. This is probably not coincidental, since carrot wasps do not sting, but could benefit by looking like other wasps that can sting.

You can easily identify carrot wasps by the following characters:

• Pronounced “neck” between head and thorax.
• Abdomen attached high up on the thorax, not between hind legs.
• Hind tibiae swollen (think “leg warmers”).
• Antennae with 13 segments (male) or 14 segments (female). Ichneumon wasps have far more antennal segments.
• Ovipositor sometimes with a white tip

Species identification often hinges on the texture of various parts of the thorax; and to a lesser degree on color pattern.

These are not terribly large insects, from 13-40 millimeters depending on the species, and much of that length owing to the long ovipositor in females. They are so skinny they remind one of a flying needle.

The adult wasps are most often encountered at flowers, especially those umbelliferous blooms in the parsley family, hence their common name of “carrot wasps.” I have also seen them at White Sweet Clover (Melilotus alba) and Desert Broom (Baccharis sarothroides), and Leafy Spurge (Euphorbia esula). Flight activity seems to peak in late spring (latter half of May) and/or mid-summer (July).

male

The biology of gasteruptiids is rather poorly known, but so far our North American species appear to be parasites of solitary bees and wasps that nest in twigs or borings in wood. The female wasp needs her long ovipositor to reach the depths of a host’s tunnel and deposit an egg. The larval carrot wasp that hatches usually feeds on the pollen, nectar, or prey stored as food for the host larva, rather than the host larva itself.

Trap-nesting for solitary bees and wasps could easily reveal many more host records for Gasteruption wasps, if one keeps careful notes.

Sources: Jennings, John T. and Andrew R. Deans. 2006. “Gasteruptiidae,” The Tree of Life Web Project, Version 22.
Smith, David R. 1996. “Review of the Gasteruptiidae (Hymenoptera) of Eastern North America,” Proc. Entomol. Soc. Wash. 98(3): 491-499.
Townes, Henry. 1950. “The Nearctic Species of Gasteruptiidae (Hymenoptera),” Proc. U.S. Nat. Mus. 100(3259): 85-145 (Note that this reference includes what is now the family Aulacidae).

Spider Sunday: Eastern Parson Spider

One of the more common and distinctive members of the family Gnaphosidae is the Eastern Parson Spider, Herpyllus ecclesiasticus. It gets its common name from the black and white color pattern that is reminiscent of the garb worn by old-time clergymen. It also sometimes makes house calls, which can be disconcerting to homeowners.

This species prowls mostly at night, and I find it fairly commonly around buildings, hoping to prey on small insects attracted to outdoor lights. It climbs well, so can be seen well off the ground.

By day, it hides under loose bark, or stones, boards, and other debris on the ground. Specimens that enter homes at night may seek refuge in clothing, shoes, and other objects. The spider may bite if trapped, but the effect of a bite depends mostly on the victim’s immune response. Rarely do symptoms exceed mild inflammation.

This is a mid-size spider, females ranging from 6.5-13 millimeters in body length. Males are 4.5-6.5 millimeters. The spinnerets are prominent in both genders, a characteristic of the family Gnaphosidae. Each spinneret is like a showerhead, with many tiny orifices through which silk is extruded.

The Eastern Parson Spider is widespread everywhere east of the Rocky Mountains, from southern Alberta across to Nova Scotia and south to Texas and Florida. West of the Rockies it is replaced by the Western Parson Spider, Herpyllus propinquus. Look for it in deciduous woodlands.

Mature specimens of this spider can be found year-round, suggesting it is fairly long-lived. Mated females spin an egg sac in autumn. The case is flat, and deposited in a silken retreat where the mother guards it. One egg sac in Connecticut, found under loose bark, contained 130 spiderlings.

Sources and Links: Aitchison, C.W. 1984. “Low-temperature Feeding by Winter-active Spiders,” J. Arachnol. 12: 297-305.
Cox, Shelly. 2011. “Eastern Parson’s Spider,” MObugs
Edwards, Robert L. and Eric H. 1997. “Behavior and Niche Selection by Mailbox Spiders,” J. Arachnol. 25: 20-30
Guarisco, Hank. 2007. “Checklist of Kansas Ground Spiders,” Kansas School Naturalist 55: 16 pp.
Minerva Webworks, LLC. 2012. “Eastern Parson Spider,” Sutton, Massachusetts, suttonmass.org.

Wasp Wednesday: Pepsis grossa

There are many species of “tarantula hawk” wasps in the western U.S., but the largest is Pepsis grossa, formerly known as Pepsis formosa. Interestingly, this insect exhibits both an orange-winged (xanthic) form, and a black-winged (melanic) morph. The two are almost never found together in the same location.

female xanthic form

My experience with P. grossa has been confined to southeast Arizona, but the species ranges from southern California and Nevada to Kansas, Texas, Arkansas, and Missouri. It also occurs throughout the Caribbean islands, Mexico, Central America, and northern South America. The xanthic form is found from Arizona north and east, and also in central Mexico. In southern Ecuador and northwest Peru, there is a “lygarochromic” variation whereby the wings are dark at the base, with a median patch of dark amber, and a pale wingtip.

These are enormous wasps impossible to overlook. Females average a whopping 43 millimeters in body length (30-51 mm). Males are smaller, 24-40 millimeters.

male melanic form

These giants can still be confused with the very similar, but smaller P. mexicana. Males of P. grossa can be distinguished by the fact that they have twelve antennal segments. No other Pepsis species has that number of segments. Females of P. grossa have long, coarse hairs beneath the femur of the front leg, though this feature can be abraded in older, worn specimens.

Females hunt for their tarantula prey mostly in the morning and evening to avoid overheating in the intense summer sun. Flying low over the ground, they may detect the presence of a tarantula burrow by sight or smell. Occupied tarantula burrows have a silk curtain over the entrance by day, and perhaps the wasp is tuned in to chemicals in the silk that indicate a spider is at home. The wasp may also land randomly and scour the soil on foot, flicking her wings and bobbing her antennae feverishly.

Once she does find a burrow with a spider inside, she cuts away the silk curtain and cautiously enters the burrow. Soon, both wasp and spider erupt from the burrow. This eviction behavior is crucial to the wasp’s success in securing her prey. She would have far less room to maneuver inside the spider’s tunnel.

The wasp steps back, grooms herself thoroughly, and then sizes up her adversary. She uses her antennae to entice the spider into raising itself off the ground; or even antagonizes the arachnid into a threat posture whereby the tarantula raises its front legs high, exposing its fangs. The wasp then seizes the second leg and thrusts her stinger between the base of its leg and its sternum. She strikes a nerve center in that location which causes the spider to become paralyzed.

The wasp may feed on fluid from the wound created by her stinger, or groom herself again before commencing the laborious procedure of carrying her prey away.

Tarantula hawks often simply drag their paralyzed burden into back into its old burrow, but on occasion they may dig another burrow and bury the spider there. I am pretty certain I witnessed the very end of this sequence one evening at Tohono Chul Park in northwest Tucson. The female shown below was busy filling a shallow depression by scraping sand into it.

female melanic form

The female lays a single egg on the tarantula and then seals the burrow. The larva that hatches from the egg will then consume the spider. Once finished, the larva will spin a silken cocoon, metamorphose into the pupal stage, and eventually emerge as an adult wasp sometime later.

Look for both male and female tarantula hawks on flowers, especially milkweeds (Asclepias spp.), where they fuel themselves on nectar. During the heat of midday, they will seek shelter amid foliage on trees and shrubs, sometimes gathering by the dozens on one plant. Males, and the odd female, may also spend the night in such aggregations.

Despite their intimidating size, these are rather placid animals unless provoked. An agitated tarantula hawk adopts a threat posture with wings splayed and abdomen curled under. They also secrete a strong, but not unpleasant, odor. Take heed! Stings from Pepsis are not life-threatening unless you are prone to allergies, but the pain is incredible. According to Justin Schmidt, you are in agony for about three minutes, and then it is pretty much over (the pain). Actual results may vary, so I am not volunteering to experiment any time soon. Neither should you.

Sources: Alcock, John. 2000. “The Tarantula Hawk Wasp’s Potent Sting Stuns and Kills the Much Larger Tarantula,” Arizona Highways, 76(10): 40-41.
Hurd, Paul David, Jr. 1952. “Revision of the Nearctic Species of the Pompilid Genus Pepsis (Hymenoptera, Pompilidae),” Bull. Am. Mus. Nat. Hist. 98(4): 261-334.
Punzo, Fred. 2007. “Interspecific Variation in Hunting Behavior of Pepsis grossa (Fabricius) and Pepsis thisbe Lucas (Hymenoptera: Pompilidae): A Field Study,” J. Hym. Res. 16(2): 297-310.
Schmidt, Justin O. 2004. “Venom and the Good Life in Tarantula Hawks (Hymenoptera: Pompilidae): How to Eat, Not be Eaten, and Live Long,” J. Kans. Entomol. Soc. 77(4): 402-413.
Vardy, C.R. 2002. “The New World tarantula-hawk wasp genus Pepsis Fabricius (Hymenoptera: Pompilidae) Part 2. The P. grossa- to P. deaurata-groups,” Zool. Verh. 337: 1-134.

Spider Sunday: Hentz's Orbweaver

Some spiders simply cannot be ignored, and judging by the volume of images and questions we get over at Spiders.us, the most conspicuous spider of late summer and fall is one of the spotted orbweavers: Neoscona crucifera. Indeed, the spiders and their webs are very conspicuous.

This species was formerly named Neoscona hentzii, hence the common name. It is also known as the “Barn Spider,” but it unfortunately shares that name with another orbweaver, Araneus cavaticus. The two look similar in size, shape, and color. Neither species has a distinct pattern, but the markings on the underside are often more consistent, and a slightly better way to distinguish the two in the field.

Mature females of N. crucifera measure 9-20 millimeters in body length, while males range from 5-15 millimeters.

This is a widespread spider, found from Massachusetts to Minnesota, Nebraska, Colorado, and southern California, south to Florida and central Mexico. It favors moist woodland habitats, but can turn up in yards, gardens, parks, and even under the eaves of homes and other buildings. Outdoor lighting attracts insects at night, and many kinds of orb weavers seem to know this. So, they may stretch their webs across your front porch, garage door, or other convenient spot where they can intercept moths, flies, katydids, and other potential prey.

Immature N. crucifera build their webs only at night, taking them down at daybreak. By removing their webs they erase any obvious clue to their presence that birds or other predators may notice. The Black and Yellow Mud Dauber, Sceliphron caementarium, and the Organ-pipe Mud Dauber, Trypoxylon politum, are especially adept at finding orb weavers by following the framework of a web. Remember, the foundation lines of spider webs are not sticky, so can be navigated with impunity by both the spider and its predators alike. The cost of losing potential daytime prey captures pales compared to the benefit of remaining undetected by your own predators.

Adult females leave their webs up during the day, the owner hiding at the periphery of the snare in a curled leaf, or huddled on a twig.

She usually sits head-down in the center, or “hub,” at night. As insects become scarce in autumn, she needs to maximize her prey-catching opportunities, both day and night. The spider consumes a damaged web, recycling the silk.

Mature male orb weavers strike out in search of females and may be found wandering almost anywhere. Not only do adult males not bother spinning webs once they are sexually mature, but they actually lose the physical capacity to do so. They no longer manufacture the types of silk necessary to spin a web. All energy goes into finding a mate. The males mature faster than the females, so some may patiently wait in the vicinity of a female’s web until she becomes an adult.

male

Once mated, females prepare an egg sac, laying up to 1,000 eggs in a spherical or convex mass, covering it with a layer of fluffy, yellow silk, and usually concealing it in a rolled leaf. The sac measures only 5-12 millimeters in diameter.

Orb weavers in general are great to have around your home as they kill many insect pests. Their webs are glorious accomplishments of animal architecture; and the spiders themselves are harmless to people and pets, despite their sometimes intimidating size. Enjoy their beauty and presence before the killing frosts come.

Sources: Barnes, Jeffrey K. 2003. “Hentz’s Orbweaver,” University of Arkansas, Arthropod Museum Notes No. 23
Lapp, Joe. 2007. “The Intelligent Neoscona crucifera,” SpiderJoe.com.

Wasp Wednesday: Blue-winged Wasp

One of the most common solitary wasps of late summer and fall is a member of the family Scoliidae known as the “Blue-winged Wasp,” Scolia dubia. This is a fairly large insect, 20-25 millimeters in length, and easily identified by its bi-colored abdomen: Black on the upper half and red on the bottom half, with two bright yellow spots in the red area. There is rarely any variation in that color scheme, either. The common name stems from the brilliant blue highlights in the black wings that shine when sunlight hits them just right.

Scolia dubia is also a widespread species, found from Massachusetts to Florida, and west to Colorado, Arizona, and southern California. I have found them in New Jersey, Ohio, and Colorado. They are parasites of the grubs of scarab beetles, particularly the Green June Beetle, Cotinis nitida, and Japanese Beetles, Popilla japonica. Since Colorado has neither of these species, the Blue-winged Wasp must exploit a different host here. We certainly have plenty of May beetles (genus Phyllophaga), and the Bumble Flower Beetle (Euphoria inda), so I suspect those are the local hosts here in Colorado Springs.

The female wasp somehow divines the presence of beetle grubs underground while flying low over the surface of the soil in what approximates a figure-eight pattern. When she detects one, she lands, and sets about unearthing it. Scoliid wasps have strong legs that are heavily spined. This adaptation facilitates their digging activities.

An exposed scarab grub will writhe around and seek to rebury itself immediately. The wasp stings the larva to paralyze it and allow her to manipulate it. She may leave the grub in situ, or tunnel below it, excavating a small chamber where she deposits the beetle larva and lays an egg on it, perpendicular its body. She then seals the chamber and leaves to start the process all over again, often staying underground and digging her way to the next grub.

Interestingly, these wasps may sting several grubs without laying eggs on them. The paralysis of the beetle larva is usually permanent, so regardless of whether they become food for larval wasps, the beetle grubs are unable to complete their own life cycle. This is a good thing if you happen to have an infestation of “white grubs” in your lawn or garden.

Back to the egg on the beetle grub, though. The wasp larva that hatches feeds as an external parasite on the grub for one or two weeks before spinning a silken cocoon around itself. There it will remain as a pre-pupa for the winter, pupating the following summer and eventually emerging as an adult wasp.

Male and female scoliid wasps commonly visit flowers to feed on nectar (and perhaps pollen). I find them most often on White Sweet Clover, Melilotus alba, thoroughworts (genus Eupatorium), and goldenrod (Solidago spp.). Males can be identified by their long antennae and overall more slender appearance. Males have a distinctive, three-pronged “pseudostinger” that is part of their external genitalia. Males cannot sting, and females are loathe to sting unless physically molested.

Another interesting aspect of the males is their behavior. Males also fly near the ground in a sinuous pattern, hoping to detect virgin females emerging from the ground. This usually happens in the morning, and males abandon their searching by late afternoon. At that time, they may gather together to roost for the night on vegetation, as the image below depicts.

© Tim Moyer via Bugguide.net

Keep an eye out for the Blue-winged Wasp in your own yard. Remember they are beneficial, but beware that large numbers of them may indicate you have a serious problem with white grubs.

Sources: Grissell, Edward E. 2007. “Scoliid Wasps of Florida, Campsomeris, Scolia, and Trielis spp. (Insecta: Hymenoptera: Scoliidae),” Featured Creatures, document EENY-409, Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences (IFAS), University of Florida.
Rau, Phil and Nellie. 1918. Wasp Studies Afield. Princeton, NJ: Princeton University Press. 372 pp (Dover Edition).