Sunday, March 30, 2014

Candystripe Spider

Our most familiar cobweb weavers, like the Common House Spider and black widow, seem most abundant in or around buildings, so it might come as a surprise to learn that many, if not most, members of the family Theridiidae live outdoors in the strictest sense. One of the larger “wild” cobweb spiders is the Candystripe Spider, Enoplognatha ovata. It is also known as the “Polymorphic Spider” because it has several color variations.

This species is probably native to Eurasia, introduced to North America long ago. It is now a very common spider in New England, the Great Lakes region, and the Pacific states inland to Montana and Utah. They spin their tangled snares in understory vegetation in woodlands, and among wildflowers and herbs in meadows and fields. The spiders usually hide by day under a curled leaf. Females guard a white or bluish egg sac in late summer.

Individual specimens vary from entirely white, cream, or yellow in color with or without parallel rows of black spots on the abdomen, to having paired red stripes down the back, or even a broad central red stripe. Adult females measure 4.3-7 millimeters in body length. Mature males, 3.5-5.2 millimeters, are distinguished from females by their modified pedipalps and the elongated jaws (chelicerae).


Spiderlings emerge from egg sacs in autumn, and overwinter in leaf litter and other protected niches on the ground. As they grow they are subject to parasitism by larval mites (ironically, mites are also arachnids) of the families Trombidiidae and Erythraeidae (Reillo, 1989).

I vividly recall finding this species commonly during my childhood in Portland, Oregon. Years later I found more during a visit to various forest preserves in suburban Chicago, Illinois. I find it interesting how some species are emblematic of one’s life and interests, be it birds, reptiles, or insects and spiders.

Sources: Reillo, Paul R. 1989. “Mite Parasitism of the Polymorphic Spider, Enoplognatha ovata (Araneae, Theridiidae), from Coastal Maine,” J. Arachnol. 17: 246-249.
Sollfors, Stefan. 2008. “Enoplognatha ovata,”
Anonymous. 2013. “Comb-footed Spider, Enoplognatha ovata,” NatureSpot.

Wednesday, March 26, 2014

Forestflies (Spring Stoneflies)

Ever since we decriminalized the sale of marijuana in Colorado, people here seem to think that “stonefly” is a term that describes an insect trapped in a bong. That would be a stoned fly. Anglers know the difference, and right now is the time for “hatches” of spring stoneflies in the family Nemouridae along the Front Range.

The species I find most commonly probably belong to the genus Zapada, known as “forestflies.” I haven’t bothered to catch any specimens and turn them over. The cervical (“neck”) gills of the larval stage (nymph or naiad) are retained by the adult and are diagnostic. Two sets of branched gills on each side of the body mean it is in the genus Zapada.

© Arlo Pelegrin via

Stoneflies in general are excellent indicators of water quality in streams and rivers because they are more sensitive to pollution, dredging, and other alterations to their habitat than many other aquatic insects. Spring stoneflies, which are also known as “little brown stoneflies,” are tolerant of a moderate amount of pollution and other human disturbance.

© J. Bodenham in Ward & Kondratieff, 1992

Nymphs of Zapada cling to submerged rocks and other heavy objects in flowing waters. There is one generation per year for the common species Z. cinctipes, meaning it is “univoltine.” Some other species require 2-3 years to complete their life cycle. The nymphs feed on vegetable matter, mostly leaves that fall into the water. Aquatic insects that chew up leaves are known as “shredders.”

© Tim Loh via

Adult forestflies can begin emerging as early as late February, but most have their peak emergence from mid-March to mid-April. Mature nymphs, and adults, measure only 5-8 millimeters in body length (not including the wings of the adult), so these are not conspicuous insects. Adults are most often seen on bridges or logs that stretch across streams and creeks. They are quite active, running rapidly and flying when startled.

Considering the rich history of mining in the Pikes Peak region, and various chemical spills that have contaminated the few creeks and rivers here in Colorado Springs, I am rather surprised that forestflies continue to prosper.

Sources: Adams, Jeff and Mace Vaughan. 2003. Macroinvertebrates of the Pacific Northwest: A Field Guide. Portland, Oregon: The Xerces Society. 16 pp.
Brown, Wendy S. 2005. “Plecoptera of Gunnison County, Colorado,” The Aquatic Insects of Gunnison County, Colorado.
Stewart, Kenneth W. and Bill P. Stark. 1993. Nymphs of North American Stonefly Genera (Plecoptera). Denton, Texas: University of North Texas Press. 460 pp.
Ward, J.V. and B.C. Kondratieff. 1992. An Illustrated Guide to the Mountain Stream Insects of Colorado. Niwot, Colorado: University Press of Colorado. 191 pp.

Friday, March 21, 2014

Spring White

Fashion rules dictate that one cannot where white after Labor Day, but the Spring White butterfly, Pontia sisymbrii, need never worry. These pale insects expire long before that arbitrary deadline. Indeed, these are among the first butterflies of spring here along the Colorado Front Range, often appearing before the official date of the spring equinox.

Heidi and I have seen several specimens already this year, on March 9, along the Arkansas River below Pueblo Reservoir. I expect to see them any day now here in Colorado Springs.

These are wary butterflies that perch frequently but startle easily. Approaching one to take its photograph is usually an exercise in futility. Males are known to “hilltop,” flying along the tops of ridges and buttes to intercept females flying up from below. You can also find them in canyon bottoms, the topography funneling females into those areas.

Like most members of the family Pieridae, caterpillars of the Spring White feed on cruciferous plants: mustards and their cousins. Females deposit one egg at a time on the stems and foliage of host plants, especially hedge mustards (Sisymbrium spp.), tansy-mustard (Descurainia spp.), and rock-cresses (Arabis spp.). In some places in northern California, Brewer’s Jewelflower, Streptanthus breweri, produces orange spots that mimic the eggs of the butterfly. The female insect avoids those plants, since caterpillars are known to cannibalize each other when too many are on one plant (Pyle, 2002).

The caterpillars hatch from the eggs in roughly a week and begin feeding in earnest. The larvae progress through five instars (an instar is the interval between molts, first instar being what emerges from the egg), and older caterpillars are quite attractive as you can see in the image below, shot by Aaron Schusteff and borrowed from

© Aaron Schusteff via

At the end of the fifth instar, the caterpillar graduates to the pupa stage. The chrysalis is described as being mottled brown or black with a granular texture. While the chrysalids of most pierids are each suspended in a “girdle,” a belt-like strand of silk around the midsection and attached to the substrate at two points, the Spring White pupa lacks this feature. It attaches to the surface of the leaf, stem, or other object only at the tail end of its body. Hooks fasten into a tiny pad of silk to secure it firmly.

Some specimens have a nearly pure white upper surface

This butterfly ranges over most of the U.S. west of the Rocky Mountains, including the mountains of Arizona and New Mexico, spilling over the divide into extreme western South Dakota and the panhandle of Nebraska. It also occurs in south-central British Columbia. In Oregon and Washington it is found east of the Cascade range (and in the mountains of the Olympic peninsula in Washington).

Look for this species early in the season, from late February on through the end of June. It frequents foothills and higher elevations. It flies earlier than most whites, but pay attention to the dark pattern of veins on the underside of the hind wings to cinch an identification.

The Spring White may be a more accurate predictor of the arrival of spring than Punxsutawney Phil, the famed groundhog, at least here in the western U.S. Good luck getting the butterfly to pose for a photo opp, though.

Sources: Brock, Jim P. and Kenn Kaufman. 2003. Kaufman Field Guide to Butterflies of North America. Boston: Houghton Mifflin Company. 384 pp.
Lotts, Kelly and Thomas Naberhaus, coordinators. 2014. “Spring White,” Butterflies and Moths of North America.
Pyle, Robert Michael. 2002. The Butterflies of Cascadia. Seattle: Seattle Audubon Society. 420 pp.

Saturday, March 15, 2014

Snail-killing Flies, genus Sepedon

You never know where learning the life cycle of an insect will take you; or how it might advance prevention of parasitic diseases on another continent. In this special procrastination edition of “Fly Day Friday,” we take a look at the fascinating fly genus Sepedon in the marsh fly family Sciomyzidae.

I was reminded of the strange lives of marsh flies when Heidi spotted one while we were walking our dog on an urban trail beside Fountain Creek in south Colorado Springs on February 24 of this year. I was surprised to see a specimen of Sepedon this early in the year, but there it was (image above).

There are twenty species of Sepedon currently recognized in North America (Knutson and Orth, 2001). These species are arranged in “species groups,” based on shared characteristics.

What is truly captivating is not the taxonomy (classification) of these flies, but their life cycle. The larvae of all Sepedon species are predators of aquatic pulmonate snails. These are air-breathing mollusks that have a simple lung in addition to, or instead of, gills.

Killing and eating snails is not without its risks. The fly larvae live just beneath the surface of the water, suspended by water-resistant hairs surrounding their posterior spiracles (breathing holes). The snails attacked are species without an operculum, the hardened plate that can seal the animal firmly inside its shell. So, a predatory fly larva won’t have the door slammed in its face when launching an attack. Still, the maggot can become suffocated by mucous excreted by the snail in self-defense; and the water-repellent hairs on the larva can get enmeshed in snail feces (Maharaj, et al., 1992).

Despite such perils, the fly larvae are efficient predators. Different lab studies have shown the larvae of different species can consume, individually, anywhere from eight to nearly fifty snails. Granted, many victims are very small. Indeed, the successful completion of a Sepedon life cycle depends on the availability of juvenile mollusks as prey for the first and second instars (an instar is the interval between molts). The third (and final) instar larva can take substantially larger snails.

Sepedon larva (A); posterior spiracles (B); anterior segments (C) ©Valley City State University, North Dakota

In the tropics, some aquatic snails are hosts of parasites, particularly schistosomes that can affect humans directly, and livestock liver flukes. Consequently, control of these snails is desirable. The possibility of employing snail-killing flies as biocontrol agents has been pursued with some vigor, but the few field trials have yielded mixed results.

Once a larva matures, it pupates. The puparium is capsule-like and boat-shaped, upturned at the posterior end, the better to float amidst organic matter at the margins of ponds or the shores of flowing waters. An adult fly emerges sometime later (a cursory search yielded no duration for the pupal stage).

Male flies have the tibia of the hind leg bowed in shape, and the hind femur swollen and armed with teeth. These features help embrace the female during courtship and mating. The general appearance of both genders is a more-or-less “stretch limo” of the fly world, sleek and slender, with a concave face and jutting antennae.

Mated females deposit small numbers of eggs in masses on emergent vegetation, so look for these insects in swampy areas, along the edges of ponds, and the banks of streams and rivers, even drainage ditches. A water course need not be flowing permanently to host both the flies and their snail prey. The adult flies overwinter, too, which explains how Heidi managed to find one so early this year.

Sources: Fisher, T.W. and R.E. Orth. 1983. “The Marsh Flies of California (Diptera: Sciomyzidae),” Bull. California Insect Survey vol. 24, 1-117.
Knutson, Lloyd Vernon and Jean-Claude Vala. 2011. Biology of Snail-killing Sciomyzidae Flies. Cambridge: Cambridge University Press. 526 pp.
Knutson, L. and R.E. Orth. 2001. “Sepedon mcphersoni, N. Sp., Key to North American Sepedon, Groups in Sepedon s.s., and Intra- and Intergeneric Comparison (Diptera: Sciomyzidae),” Proc. Entomol. Soc. Wash. 103(3): 620-635.
Maharaj, R., C.C. Appleton, and R.M. Miller. 1992. “Snail predation by larvae of Sepedon scapularis Adams (Diptera: Sciomyzidae), a potential biocontrol agent of snail intermediate hosts of schistosomiasis in South Africa,” Med. Vet. Entomol. 6(3): 183-187.
Neff, S.E. and C.O. Berg. 1966. “Biology and Immature Stages of Malacophagous Diptera of the Genus Sepedon (Sciomyzidae),” Blacksburg, VA: Virginia Polytechnic Institute, Agricultural Experiment Station Bulletin 566. 113 pp.
images of larva from Valley City State University, Valley City, North Dakota, Macro-invertebrate Lab, Digital Key to Aquatic Insects of North Dakota.

Tuesday, March 11, 2014

My Next Book

I must admit that I have had a hard time keeping this news under wraps, but now that the paperwork is complete I can officially announce that I will be authoring the Princeton Field Guide to Spiders (official title to be decided later). This will represent my first true solo effort, and with that comes a great deal of responsibility.

It is not lost on me that this may appear to be a redundant work in light of recent popular works on North American spiders. I intend for a fundamentally different publication, though. This will be a true field guide, one that is more portable than either a “manual” or other reference book. Emphasis will be on what can be observed in the field without killing a specimen (though confining one to a vial would allow for closer observation). The appearance of webs, burrows, retreats, and egg sacs, as well as the arachnid itself, will be included. Habitat, geographic range, and behaviors will also be highlighted.

My intuition and experience suggest that what a general audience most wants to know is whether any given spider poses a dangerously venomous threat to themselves, their family, pets, or co-workers. Few references of recent vintage have understood this, and so the resulting books have been overwhelming and of little relevance to what is mostly an urban and suburban audience. These books have also been pricey. Princeton understands that a product of this nature needs to be reasonably affordable.

The other side of the ledger means, naturally, that budgets for the author, and compensation for image usage, is a little less than perfect. Ideally, I would like to come in under budget, and before the April 1, 2016 deadline for delivery of the manuscript and graphics. Some of you will hear from me during this process, as I value your knowledge of arachnids, and/or admire your digital photographic skills.

There is no question that many, if not most, spiders can be reliably identified to species (sometimes even genus) only by examination of minute physical characters, including male and female genitalia. This book will freely admit as much, but the overall intent is for a novice to be able to at least tell what family a given specimen belongs to. We will include a “similar spiders” paragraph for each entry to help users compare to other potential candidates.

I can guarantee that my number one priority is accuracy. I have the utmost respect for arachnologists, especially those who have made an effort to share their expertise with the public; and involving citizen scientists in an effort to broaden our overall knowledge of spider diversity and distribution.

At the core, however, is the fact that I am a professional writer, and that is why the people at Princeton University Press selected me for this project. I appreciate an understanding of my role as a communicator, and forgiveness for whatever I may lack in academic and scientific credentials. The “acknowledgements” page is blank. I look forward to adding your name. Thank you.

Sunday, March 9, 2014

Ground Spiders, Sergiolus

Few spiders are as colorful as those in the genus Sergiolus. Why they are so boldly marked is something of a mystery, though there is suspicion that they may be mimicking velvet ants, wingless wasps in the family Mutillidae that pack a potent sting. Sixteen species of Sergiolus are known north of Mexico.

Sergiolus sp. male from Indiana

These nomadic arachnids are very agile, at least when fleeing potential danger, and they often prowl through leaf litter, so you may only get a glimpse of one. Be patient, though, and it is likely to reappear. They are also good climbers, so don’t be surprised to find them on foliage, or walls, too.

Sergiolus are medium-sized members of the family Gnaphosidae, females ranging from 6-10 millimeters in body length, males 5.5 to 7 millimeters. They are mostly diurnal (day-active), so are even more conspicuous than the average spider. The obvious, cylindrical spinnerets at the tip of the abdomen are characteristic of all Gnaphosidae, but helps distinguish Sergiolus from colorful spiders in other families. There are other ornate gnaphosids, such as Callilepis, and separating the different genera hinges on subtle distinctions in the genitalia (epigynum of females, pedipalps of males).

Male Sergiolus sp. from Colorado

Since there are several species, I am reluctant to assign specific names to the images shown here. One of the more abundant species found from the Nebraska and Oklahoma eastward is S. capulatus, sometimes known as the Variegated Spider. It bears an uncanny resemblance to velvet ants in the genus Timulla, which frequent similar habitats: sun-dappled patches on the floor of deciduous forests. The spider is also found in gardens, meadows, even lawns.

Female Timulla sp. velvet ant

One common western species is S. montanus.

While Sergiolus does not spin webs to snare prey, they do construct retreats in which to molt, guard an egg sac in the case of females, and perhaps to overwinter. They probably live over a year, as adults can be found in almost any season. Obviously, they are most active during the warmer months.

Look for these and other spiders, as well as insects, in sunlit spots in wooded areas. You will be surprised at what shows up if you simply sit and watch. Sergiolus can also be found under stones and other objects in reasonably dry situations.

Male Sergiolus capulatus? from Indiana

You can keep gnaphosids in captivity with relative ease. Almost any container will do. Provide them with water, as they do not obtain water from prey. I furnish a small wad of cotton soaked in water at least once per week. A small insect can be fed to a spider every other week or so. Spiders are built to withstand surprisingly long periods without food. Remove the prey insect if it has not been consumed within two days. Spiders preparing to molt will not feed and are therefore vulnerable themselves to predation.

Note: Several members of the genus Sergiolus were once placed in the genus Poecilochroa, and older references treat them as such.

Sergiolus montanus? from Colorado

Sources: Bradley, Richard L. 2013. Common Spiders of North America. Berkeley: University of California Press. 271 pp.
Kaston, B.J. 1978. How to Know the Spiders (Third Edition). Dubuque, IA: Wm. C. Brown Company Publishers. 272 pp.
Ubick, D., P. Paquin, P.E. Cushing, and V. Roth (eds). 2003. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.

Wednesday, March 5, 2014

Life in a Paper Palace

Back in the 1980s I began my writing career as a volunteer with the Audubon Society of Portland (Oregon). A group of us produced an award-winning publication called The Urban Naturalist. I thought it might be interesting to visit some of those old articles, like this one in the spring, 1987 issue.

It is a battle royal. Queen versus queen, locked in deadly combat with gnashing jaws and jabbing, venomous stingers. A scene from a science fiction soap opera? Alexis versus Crystal? No. At stake is a kingdom of social wasps and the beginning of an annual dynasty.

While most wasps are solitary, the yellowjackets, hornets, and paper wasps are colonial. No true hornets occur in Oregon, but six species of yellowjackets thrive in the Portland area. All belong to the family Vespidae. Three types of adult wasps are present in a mature colony: one reproductive female or queen, many subordinate females called workers, and males or drones. Each princess and prince begins life as an egg, laid in a single, hexagonal paper cell. The egg hatches into a hungry, white larva. Workers feed the grub protein in the form of chewed-up insects or pieces of carrion. The larva grows rapidly, eventually filling its confining cell. Soon, the larva weaves a silken dome over its cell and transforms into a pupa, the resting stage in which its organs are miraculously rearranged into those of an adult wasp. The full-fledged insect then chews off the cap on its cell and emerges.

The entire colony goes through a similar life cycle, beginning in early spring. Not every nest has a violent genesis, but real estate is hard to find and competition is keen. If fate leads a queen to a site already occupied by a nest, she may engage the resident queen in a duel to the death.

Once established, the royal family can grow and prosper through the summer, wrapped inside an architectural masterpiece. The marvelous combs of cells, where the offspring develop, are made wholly of wood fibers, chewed into a papery pulp and mixed with saliva. The combs are stacked, connected by sturdy paper pillars. A multi-layered paper envelope encloses the combs to insulate and complete the durable castle.

The workers expand and repair the elaborate structure, and also defend themselves and nestmates, using their needle-like stingers liberally. Some species can even spray their venom! Only the females possess a stinger which is evolved from the ovipositor, an egg-laying organ. If a battle between queens leaves a young colony orphaned, workers can even produce progeny themselves. Normally, the presence of the matriarch suppresses the reproductive potential of the workers. In her absence, they may lay unfertilized eggs which give rise to males!

The population of a typical colony peaks at a few hundred to several thousand royal subjects when new queens and males mature in the late summer and early fall. They are not accorded the pomp and circumstance granted a royal wedding, but the brief nuptial flights serve their purpose of procreation. Afterwards, the males soon perish.

Male Western Yellowjacket

With the departure of the queens, including the founding mother, the empire begins to crumble. The workers, normally passive, become highly agitated, attacking other creatures without provocation. They may cannibalize the larval wasps remaining in the nest, or simply throw them out.

The kingdom they created with such care, they now seem to destroy with ruthless determination, reminiscent of the deterioration of the Roman empire. For yellowjackets, though, there is a resurrection. After mating, the queens seek appropriate places to spend the winter in hibernation. Most often they hide under bark on stumps and logs, curling their legs and wings beneath them. They awake the following spring to initiate their own colonies.

Be on the lookout for yellowjacket nests overhead and underfoot. The baldfaced “hornet,” Dolichovespula maculata, builds its enormous nests among blackberry canes, low in trees, and shrubbery. Some of these structures are as big as basketballs! Thankfully, the occupants are gentle in nature. Most importantly, these large black and white wasps kill great numbers of flies to feed the larvae in the nest. Sometimes, they prey on other yellowjackets, too.

D. arenaria also builds above ground, often suspending its aerial palaces from human dwellings. The nests, and the wasps themselves, are usually small. These are yellowjackets in the truest sense, colored in alternating bands of black and yellow. They, too, prey on other insects to feed their younger siblings.

By far the most abundant and pesky species is the Western Yellowjacket, Vespula pensylvanica. Large colonies of this wasp live in subterranean nests, built in abandoned rodent burrows, rock walls, and similar cavities. What makes them a nuisance is their habit of scavenging for foodstuffs at picnics, in garbage cans, and other urban situations.. They are predators, too, sometimes killing honeybees to feed on the nectar stored in a bee’s gut. They also will swarm over ripe fruit to feed on the juices, and sip the honeydew secreted by aphids and scale insects.

The Common Yellowjacket, V. vulgaris [Edit: now V. alascensis], is very similar to the Western Yellowjacket in size, color, and habits. It, too, often feeds on carrion and human foodstuffs and becomes a pest.

Prairie Yellowjacket queen (center) with "xanthic" (yellow) and "melanic" (black) workers

V. consobrina, the Blackjacket, resembles a smaller version of the Baldfaced Hornet, being black with sparse white lines. These scarce insects live in small colonies underground and are strictly predatory.

The Prairie Yellowjacket, V. atropilosa, is also an uncommon predator.

Yet another species will likely invade Portland this year. The German Yellowjacket, V. germanica, was originally introduced to the eastern U.S. from Europe. Besides being slightly more aggressive than native species, it has a tendency to nest in houses, between the walls! Isolated colonies have been discovered in California and western Washington, especially along the I-5 corridor. Traffic to Expo ’86 is probably responsible, at least in part, for ferrying this unwelcome immigrant to the Northwest.

Should it be necessary to remove a nest, one can do so with constructive consequences. At least one lady, Betty Pope of Rivergrove, Oregon, will rid you of problem colonies by freezing their female tenants. Their bodies can then be processed into extracts used in the treatment of stings in hypersensitive victims.

On the whole, yellowjackets are beneficial organisms. They dispose of large numbers of pest insects, and also help pollinate flowers. Studying their social behavior may shed some light on human relationships. We may learn that their mysterious population booms and busts are a metaphor for man, a disturbing thought tempered only by the reminder that yellowjackets have learned to cope successfully in an ever-changing world.

I see I had a flair for the dramatic back then. What else has changed? Entomologists were not as easily accessible back then, before personal computers and the internet. I had to use a typewriter and the telephone, and the library.

Sunday, March 2, 2014

Comb-tailed Spiders

Chances are you have never seen one of the “comb-tailed spiders,” also known as “dwarf sheet spiders,” in the family Hahniidae. Me, neither, until I started sorting pitfall trap samples at the University of Massachusetts, Amherst, for six months in 2009. Maybe you have never even heard of them before. Forgive yourself, these spiders are, while common, very seldom encountered.

Neoantistea radula male

The overwhelming majority of haniids are under four millimeters in body length….as adults. A few in the subfamily Crypheocinae can reach nearly eight millimeters. So, they are easily overlooked anyway. The images shown here are of preserved specimens under the magnification of a binocular dissecting microscope. Considering their cryptic habits, it is no wonder these escape attention.

Members of the subfamily Hahniinae, save for the genus Neoantistea, don’t even build webs (here in North America at least). The webs of Neoantistea are very thin, sheet-like, and small. They are only visible when heavily laden with dew. They are frequently stretched across the footprints of mammals, and other small depressions in the soil. The spider sequesters itself amid mosses or soil particles at the edge of the web, traveling on the underside of the web to secure prey.

Spinnerets of Hahnia sp.

The most conspicuous feature of hahniids in the subfamily Hahniinae is the arrangement of their spinnerets. All six are aligned in a single row across the back of the abdomen, presumably resembling the teeth of a comb (hence “comb-tailed spiders”). Members of the subfamily Cryphoecinae have a more “normal” arrangement, the spinnerets in two, staggered rows.

Identification of the different genera of hahniids hinges on such characters as the placement of the tracheal spiracle on the underside of the abdomen, relative size of the anterior median eyes, length of segments on the lateral spinnerets, and shape of spurs on the palps of mature male specimens. That’s just for Hahniinae. Cryphoecinae genera are distinguished mostly by features of the male and female genitalia, and dentition of the cheliceral fang furrow (groove in the jaw that receives the folded fang).

Male Antistea sp., underside of male palp showing curved spur on tibial segment

Don’t let the complexity of taxonomy discourage you from looking for these spiders and appreciating their subtle beauty. The genera Neoantistea and Hahnia, with 11 and 7 species respectively, occur throughout most of North America. Antistea brunnea ranges in British Columbia, southeast Canada, and the northeast U.S. Most of the Chryphoecinae are restricted to North America west of the Rocky Mountains, and principally in Canada and northern states, or at least in chronically rainy forest habitats.

Cryphoeca montana

Cryphoeca Montana is a nocturnal spider that has been collected from under bark on dead trees, in leaf litter, moss, and under stones.

The family Hahniidae was once lumped within the family Agelenidae, the funnel-web weavers, at least as recently as 1957, but is now recognized as a stand-alone family.

Sources: Bradley, Richard A. 2013. Common Spiders of North America. Berkeley: University of California Press. 271 pp.
Levi, Herbert W. and Lorna R. 1968. Spiders and their kin. New York: Golden Press. 160 pp.
Ubick, D., P. Paquin, P.E. Cushing, and V. Roth (eds). 2005. Spiders of North America: an identification manual. American Arachnological Society. 377 pp.