sign in sign up
<<
Home , Atypoides, Bowl and doily spider, Filmy dome spider, Frontinella, Neriene, Spiders of Australia

A Few Common Minibeast Safari Sheet Web Weavers Mygalomorph (“primitive”) Spiders Key & Biographies no legs

body w/out visible segments body w/ visible segments

↑Bowl and Doily (10) ( pyramiitela)

False (8) Turret Spider (9) CaCalisogalisoga llongitarsusongitarsus (AAtypoidestypoides spsp.).) snail (33) (34) Cobweb Weavers (16) earthworm (32) legs many pairs of legs ↑ (11) ( radiata) 15+ prs legs 1il/1 pair legs / segmen t 2il2 pairs legs / segmen t

Black Widow Badumna sp. (12) hesperus (lacy web) pillbug (31) millipede (29) centipede (30) 4 pairs of legs pincer-like appendages body in 2 parts body in 1 part House Spider Achaearanea tepoidariorum False Widow Triangle Spider (17) grossa (Uloborus sp.)

Orb Weavers (19) scorpion (28) Hunting Spiders Spider (2-24) opilione (25) (see back) harvestman daddy long legs

Crab Spider (w/ prey) tick (26) (w/ egg sac) Camouflaged sit and mite (27) Runs to catch prey (14) wait predator (15) 3 pairs of legs … a different class … another booklet 2 pairs of tiny legs

prepared by Gwen Heistand (13) Cellar Spider↑ (18) for use in ACR Education programs Jumps at prey from above (family ) California slender slamander (24) Soil/Leaf Litter Habitat 37

↑Soil Food Web ↓Fallen Log Decomposition Nitrogen Fixation Have kids take a big, big breath •Most of what’s filling your lungs is nitrogen. •No plant, , or fungus can process N2 as a nitrogen source! •78% of every cubic meter of air is nitrogen (N2). •There are seven TONS of nitrogen (N2) over every meter of the Earth surface. •Over 99% of Earth’s nitrogen exists in the atmospheric pool as N2 gas. •N2 has strong, strong bonds. They’re not easy to break down. Most of the nitrogen that is “fixed” or converted to a useful form for the rest of life is done so by nitrogen-fixing bacteria •Essentially all of the nitrogen contained within our bodies has been funneled through nitrogen-fixing bacteria Where do you find nitrogen-fixing bacteria at ACR? •Root nodules on: Alder, Ceanothus, Lupine, Vetches & Peas, Wax Myy,rtle, Clover, Lotus •Some lichens (most jelly lichens) incorporate cyanobacteria rather than algae as their photobionts •Azolla (water fern) harbors cyanobacteria in its leaves •In the guts of termites •In symbiotic association with protozoa 35 1 One square meter of soil can contain more individual Table of Contents: organisms than all the humans that every lived! 1012 bacteria Minibeast Biographies 1012 protozoa 107 nematodes, springtails & mites 107 1,000 earthworms 20,000 kilometers (12,427 miles) of fungal Taxonomic pg mycelia Group Critters # Arachnida spiders (see table of contents page 3) 2 harvestmen (opiliones) 25 Have the kids pace out one square meter (one square yard is ticks 26 about the same). You can tell them that there are more creatures mites 27 living in the top few inches of soil than all the humans that ever scorpions 28 lived. If you want to use the numbers above, you can talk about scientific notation. Use a stick and draw in the dirt a 10 with 12 Diplopoda millipedes 29 zeros after it! Chilopoda centipedes 30 Isopods woodlous, pillbugs 31 That’s 1,000,000,000,000 or 1 TRILLION bacteria. 1 TRILLION Annelida earthworms 32 protozoa. 10,000,000 or 10 MILLION nematodes springtails & snails 33 mites. 10 MILLION insects. And 12 THOUSAND MILES of fungal 34 mycelia. This is half the circumference of the earth in a single Things to take into the field 35 square meter of soil. One Square meter …. 36 Soil/Leaf Litter Habitat 37 The numbers are staggering, the biodiversity fascinating, and the potential for discovery unsurpassed by any other habitat on earth. Yet we have spent more time studying small patches of the moon and Mars than exploring the subterranean habitat of our own planet.

What are the we find in the soil doing (how do they make their living?)

Shredders / Detritivores (millipedes, isopods, termites, certain mites, roaches) Predators (spiders, pseudoscorpions, predatory mites, centipedes, predatory beetles and beetle larvae) Herbivores (cicada larvae, mole crickets, larvae (root maggots)) FlFd(Fungal Feeders (FiFungivores) (mos t spri ngt ail s, some mit es, silverfish)

What about earthworms? What about fungus? 2 Spider External Anatomy 35

Things to take into the field: 1. something to hold leaf litter (white “frisbees” work well) 2. hand lenses 3. bug boxes or other collection vials to pass around interesting critters 4. It’s easy to make a sifter box: glue some wire mesh on the bottom of a shoe box (after cutting off the bottom). Sift leaf litter through this into something else (frisbee – or another show box). OR … you can just take some wire mesh. 5. index cards or scratch paper if you want the kids to record how many different kinds of things they see

Remember to respect decaying logs: if it looks like it will fall apart if you turn it over or move it, leave it be.

If you find a critter under a stone or a log, don’t put the object back on the critter, replace the log, stone and let the critter crawl back under.

“When you scoop up a double handful of earth ... you will fi nd th ousand s of i nvert eb rat e ani mal s, rangi ng i n size from clearly visible to microscopic, from ants and springtails to tardigrades and rotifers. The biology of most of the you hold is unknown: we have only the vaguest idea of what they eat, what eats them, and the details of their life cycle, and probably nothing at all about their biochemistry and genetics. Some of the species might even lack scientific names. We have little concept of how important any of them are to our existence. Their study would certainly teach us new ppprinciples of science to the benefit of humanity.”

Wilson, E. O. 1987. The little things that run the world: The importance and conservation of invertebrates. Conservation Biology 1:344-346. 34 Mollusca: Slugs TABLE OF CONTENTS 3

Spider External Anatomy……………………………………………….. 2 slug eggs (laid in What Makes a Spider a Spider? / clutches of 3-50; will Types of Spiders (Mygalomorph vs Araneomorph spiders) ………….. 4 not lay eggs when Identification Characteristics water saturation in the …………………………………………………………... 5 soil is below 10%) Eyes………………………………………………………………. 6 Spinnerets……………………………………………………………….. 7

Mygalomorph Spiders : False Tarantula (Calisoga longitarsus) …………………… 8 Turret Spiders (Atypoides sp.)…………………….… 9

Araneomorph Spiders Trianggple spider ( Uloborus sp.)…………………………….… 17 : Sheet Web Weavers Bowl & Doily Spider (Frontinella sp.)……………………… 10 1. They poop out their sides (a result of torsion, see snails) Filmy Dome Spider (Neriene sp.)………………………… 11 2. They have a built-in continually growing (all gastropods : Funnel Web Spiders……………………………….... 12 do) to rasp plant material (some with 30,000 sharp backward : Badmuna sp. (From )…………………………….. 12 pointing teeth). : Comb-footed Spiders 3. They move on a trail of slime … imagine if your whole body Black Widow or Western Widow (Latrodectus hesperus)…… 16 could produce mucus! Mucus is used for self-defense, False Widow (Steatoda grossa)………………………………. 16 moisture control, mating. navigation House Spider (Achaearanea tepidariorum)………………….. 16 4. Resting slugs can remain attached to a surface for many hours Pholcidae: Cellar Spiders ………………………………………... 18 … mucus under a resting slug contains a dense network of Araneidae: Orb Weavers …………………………………………. 19 fine fibers that keeps them from slipping. Debris Spider (Cyclosa sp.)………………………………….. 20 5. They move by making wave-like motions with the muscles Missing Triangle Spider (Zygiella sp.)…………………………21 of their foot. Tetrignathidae: Long-Jawed Spiders………………………..…… 22 6. Most of a slug’s active hours are devoted to eating, (fungi, (Hunting Spiders) lichens, algae, plants) consuming many times their body Lycosidae : Wolf Spiders …………………………..….……...…. 14 weight every day. Salticidae: Jumping Spiders …………………………....……….. 13 7. Love Darts! (see snails) : Crab Spiders ……………………………...………. 15

Spider / Mating…………..…………………...….……… 25 Molting……………………………………………………….…….…….. 26 4 Mollusca: Snails 33 What Makes a Spider a Spider?

•Abdominal silk glands and spinnerets •Males with palpal sperm transfer •Cheliceral glands

All (spiders, ticks, mites, opiliones, scorpions, whip scorpions, pseudoscorpions, sun spiders) have:

•4 pairs of walking legs Helminthoggyplypta s p. •Two body segments (cephalothorax & abdomen) Haplotrema sp. Native Terrestrial Snails at Bouverie 2 Major Groups of Spiders Helminthoglypta sonoma: large dark colored snail (dark shell, flesh is Mygalomorph pinkish, seen on the Canyon Trail near Champagne tree) False (and real ones) along with Haplotrema minima: small, light colored, flattened shell our turret spiders and trapdoor spiders are all part of a major grouping called 1. How is the shell made? The of a snail has 3 lobes;;, muscular, mygalomorph spiders. These spiders sensory, and secretory. The secretory lobe produces the shell which is are considered to be more primitive. composed of 3 layers: Their fangs only move up and down 1. horny covering (perisotracum) comprised of protein; instead of side-to-side (they operate 2. prismatic layer comprised of polygonal prism of calcium parallel to the midline of their body, not carbonate; ppperpendicular to it ). So … m ygalomor phs 3. nacreous layer (also calcium carbonate) that is laid down in thin moves up and down need to rear up and come down on their sheets . prey, trapping them against a surface. 2. Snails (& slugs) are both male & female (hermaphroditic). 3. Love darts: Before delivering their sperm, many species (including Mygalomorphs have 2 pairs of book lungs (and only book lungs ) which garden snails) fire nasty-looking darts made of calcium carbonate into the distinguish them from all but one group of the “true spiders”. Mygalomorphs flesh of their mate. In the 1970s, scientists suggested that this was a gift also have long, segmented, spinnerets, which trail out behind their body to help the recipient raise its fertilized eggs. But it turns out that snails visiblyyygg. Their eyesight is not great and courtshi p often relies on the male don' t incorporate the calcium in the dart into their bodies. Instead, love stroking and caressing the female. Mygalomorphs are long-lived (females 8-20 darts turn out to deliver hormones that manipulate a snail‘ reproductive years, males 3-7 years!). organs. (From Love Darts by Carl Zimmer) Araneomorph (“True” Spiders) 90% of spider species are Torsion: Think about life in a shell with only one opening. How would you araneomorphs. Fangs these moves poop or have sex if those organs were at the opposite end from your head spiders (orb weavers, sheetweb and stuck inside the shell? weavers , wolf spiders, crab side-to- One of the most dramatic steps spiders, jumping spiders, etc.) are side in mulluscan evolution was the able to move side to side. Their advent of torsion. During jaws work independently from any development in all gastropods, surface and they are able to impale the visceral mass rotates so their prey between them. This that the posterior end, with the allows araneomorphs to catch prey anus, reprodtiductive openi ngs, on the flimsy surface of their webs. kidney openings and gills, Along with one pair of book lungs, comes to sit above the head most araneomorphs also have facing forwards. tubular tracheae. 32 5 Annelida: Earthworms 6 Cool Things about them! Pedipalps

Q: How can you tell a male spider from a female spider?

A: The male spider has swollen pedipalps (sometimes called palps) that make him look like he is wearing little boxing gloves. Pedipalps are one of the structures used in spider identification. They can be relatively simple of very complex.

Q: What are male pedipalps used for? 1. They have 5 hearts. A: Pedipalps are used to transfer sperm to the female. The analogous female structure is called an epigynum. The palps and 2. They eat dirt (soil) (Aristotle called them the epigynum work together like a lock and key. intestines of the soil). MlMales palps whic h trans fer sperm, are nottdtt connected to area 3. In just one acre there can be more than where sperm is produced. Males need to spin sperm webs, load one million earthworms, eating 10 tons the webs with sperm, and then charge their palps before they can of leaves, stems, and dead roots a year transfer sperm to a female. and turning over 40 tons of soil.

4. An earthworm has no lungs or gills. It breathes through its thin skin, which is in contact with the air between the particles of soil. What happens when it rains?

6: What is that lump in the middle of them? The clitellum. What is it used for? Sex … it 5. They move through the eventually soil using their produces the hydrostatic skeleton cocoon for and setae which they use ↑simple pedipalps the eggs. as anchors. (Take an earthworm and run it ← complex pedipalps gently through your lips!) 6 31 Spider Eyes Crustacea Isopoda: pillbug, woodlouse, armadillo bug, Q: What are some of the ways we can distinguish between families of potato bug, roly-poly spiders?

A: One way is the eyes. Look at the eyes – the size and placement. Who below makes their living by actively running around and looking for prey? Who might depend more on sensing web vibrations?

• Woodlice are crustaceans, so they’re related to crabs, shrimp, lobsters, etc. • 7 pairs of legs • Defend themselves by secreting chemicals or rolling up in a tight ball • Eat rotting plants and fungi (and are known to eat their own feces and other woodlice as well) • Woodlice may be eating their own poop because, in woodlice blood, it’s copper that carries oxygen (making it blue, not red). When copper from eating leaves and other decaying matter is in short supply, they may get some copper by processing their own waste. • Get rid of waste by secreting ammonia through shell as a gas (instead of peeing) • Female carries eggs in a pouch (marsupium) under her body; • eggs hatch and young woodlice remain in pouch until they are big enough to survive on their own (only have 6 pairs of legs – grow their 7th pair on their 1st molt) • Breathe through gill-like structures… so they need moist environments • Interesting way of molting! –1st sheds front half of shell; up to two weeks later sheds other half (look for two-toned pill bugs!!) • Chief predators are ants, spp(iders, and shrews (look around the ed ges of ant colonies and you’ll often see desiccated pillbug bodies). • You will occasionally find purple pill pugs … This is exciting: it means they are infected with an irridiovirus. Interestingly, a large percentage of pillbugs infected will also have been parasitized by a mermithid worm – you don’t need to know what this is. The worm can fill up more than 30% of the pill bug’s body cavity!

Most spiders have 8 eyes. Can you tell from the drawings above whose faces are in the pictures? Spinnerets 7 30 Chilopoda: Centipedes Q: How do spiders make silk?

A: They have structures called spinnerets. Silk comes out from tiny nozzles as a liquid. Tension causes it to solidify. It is one of the strongest lightweight substances known . Spider silk is 5 times stronger than steel and about 3 times tougher than Kevlar. According to the folks that have tried to raise spiders for silk, it’s like trying to farm tigers. Think about it

• Have 1 pair of legs on each segment • Move by alternating each pair of legs, making them wriggle, unlike the gliding motion of a millipede • Carnivorous hunters in the cryptosphere. • Paired pincer-like appendages in front of the legs called gnathosomes or gnathopods that are used to inject venom into their prey. • Flat body that can squeeze through narrow cracks. • Tend to avoid light. • Different sexes with complex courtship. A male and female meet in a passage in the soil. They touch each other with their antennae and move about in a sort of dance. The As you can see … spiders have different kinds of male spins a web across the passage and places a sperm silk: sticky, hackle band, egg sac, dragline, packet in it. He signals the female with his antennae and attachment disk, swathing, different structural slowly moves away. She picks up the sperm packet and types … takes it inside her. • Some mothers lay eggs and leave, others coil their bodies around their eggs and periodically unwind, pick up eggs and lic k them (sc ien tis ts thin k this may be to remove spores of molds) – see picture above (from BLP – taken by May Chen).

Colorized scanning em of silk coming out spigots Scanning em of median spinnerets 29 8 False Tarantula (Calisoga longitarsus) Diplopoda: Millipedes

Q: What do these spiders look like?

A: They’re large and “tarantula-like” though not as large as the tarantulas we are familiar with. In the fall, I often get calls from people that find large spiders in their bathrooms or around their house. The males of this species go on walk-about in the fall searching for females and it is usually this spider that people are asking about. Q: Where can we find Calisoga • Have 2 pairs of legs on each segment burrows? (centipedes have only 1) • Waves of movement pass down the body from Look in the middle of trails and trail one pair of legs to the next , causing a gliding margins,,p especiall y on the Griffin trail motion. across the Sheerin Bridge and the first • Nearly all millipedes are vegetarians, living part of trail to Volunteer Canyon. I’ve mostly on rotting plant matter. (Some also eat also seen them on the trail past the spider living molds and growing plants) patch on the way under the heronry. In • Unlike earthworms, they can’t eat their way the fall, after the first rains, they’re through the soil. They push their hard bodies easier to spot. Look for little piles of through. Young millipedes need to use cracks dirt and a white glob next to an almost and tunnels that are already there. perfectly round hole about the size of a • Many millipedes have “stink glands” used in nickel. The white glob is the remains of defenses, some even produce cyanide, like the last year’s egg sac. If you tease it open night train or almond millipede pictured above.. and have a hand lens you can see the • One of most common millipedes takes care of Q: Where do these spiders get their shed exoskeletons of the tiny her eggs, mixing saliva with dirt to form a dome- sometimes common name of spiderlings who undergo their first molt shaped nest. (The photo below is young “aggressive false tarantula”? while still in the sac! millipedes that have just “hatched” out of one of these dome-shaped nests.) A: They have a threat display of rearing Q: If these are “false” tarantulas … do • Have been known to live up to 7 years. up on hind four legs, raising and we have “true” tarantulas at MGP? • Add new segments and pairs of legs when they spreading the front four, and baring the molt fangs. The display turns your stomach A: True tarantulas ((ypFamily Theriphosidae ) upside down . are common in hot, dry areas of the East Joel Ledford Bay, like Mt. Diablo, and Henry Coe State Park. Reports of tarantulas on Mt. Tamalpais refer to Calisoga. There are no records of “true” tarantulas from Marin County. American tarantulas defend themse lves aga ins t vert eb rat e pred a tors b y scratching off fine abdominal hairs which are hollow and venom filled and irritate the nasal linings of like coyotes, foxes, and skunks. Arachnida: Scorpions 28 Turret Spider (Atypoides sp.) 9 California common scorpion Paruroctonus silvestrii (Family Antrodiaetidae)

Q: What’s the deal with the turrets?

A: Turrets are stiffened silk connected to a long silk-lined burrow in which the spider lives. Douglas fir needles, dirt, leaves, and twigs are incorporated into the turret and act as trip-lines. At dusk, the spider sits at the edge awaiting victims.

Q: When you find a large-ish turret, yyyou very often see a bunch of smaller • 2b2 bo dy par ts: cephlthhalothorax (hd+thhead+thorax)dl) and elonga tdbdted abdomen ones around it. What’s this about? with tail (telson) • Bulbous segment on end of telson (tail) = vesicle and contains the sting A. As with the trapdoor spiders, very often • Oldest known terrestrial . Folks have postulated that the offspring don’t stray too far from home. scorpions may be the first representative on land. When I hear this I Some pretty cool population studies have always think, “great! … and if scorpions ’ main diet is other arthropods been done with turret spiders. … what did the first scorpions eat?” • All scorpions spend daylight hours under cover. Come out at night to defend territories and hunt. (nocturnal) • Capture prey with pincers, paralyze with sting • Elaborate courtships: Male holds female’s chelae (pincers) clasped Q: What do these spiders look like? in his own and leads her in a dance that can last up to several hours! When the time is right, the male deposits a sperm package on the A: They are mygalomorph (?!) spiders that look a little like ground and dances the female over i so she can pick it up and use it to tarantulas. They have thick bodies and small eyes. fertilize her eggs. • Young are born alive; female carries them on her back until at least female in their first molt; molt 7 times to reach maturity (approximately 1 year) burrow • Only sting when handled or molested. male out in GCC searching for female 

Q: How often do these spiders need to eat?

A: As often as they can … AND they can wait six months without eating. They may even shed their skin to get smaller if need be! 10 Bowl & Doily Spiders (Frontinella sp.) Arachnida 27 (Family Liniphiidae – Sheet web weavers) Mites

fungus-eating Some fungus eating mites predatory Q: How does this web work?? are “armadillo” mites – they prey on nematodes, can fold up their bodies; they springtails, other mites, and AThA: The snare cons itists o f a cuplike s truct ure (bow l) a bove a shtheetweb look like little seeds the larvae of insects . (doily). The spider sits on the underside of the cup. Small flying and crawling insects get caught in the many trap lines constructed above and around the bowl and tumble in at which point the spider bites them from below and pulls them through the web. The Bowl and Doily. Does the “doily” or “saucer” play a role? Yes, It is composed of fresh spider silk just like the bowl or cup. They spider, resting below the surface of the bowl, is protected from attacks from below by the doily. Frontinella then wraps its prey in silk and saves it for when it wants to eat Q: Are there any “web parasites” in the spider world, like there are “nest parasites” in the bird world?

A: Funny you should ask! Yes. Argyrodes trigonum is a kleptoparasite of bowl & doily spiders that feeds on their food – and, as been recently mites from a single small sample of leaf litter shown, occasionally them. In summer months, A. trigonum may inhabit up (in one sample from the Pike County Gulch to 20% of bowl and doily webs, where it has caused death or departure of experiment, we counted over 2,000 mites … its host. Possibly as a result of this, Bowl and doily females will actually and they all fit in less than a teaspoon) allow males to use their webs to capture prey. It is thought that the function of this ppy()ermissiveness may be to deflect (onto the males) the risk of being captured. (Bowl and doily spiders also go through what is termed You will a lso fin d little aqua tic m ites sw imm ing aroun d in pon ds an d pseudocopulation. The male will get close enough to determine whether or streams, gorgeous red mites in the salt marsh, mites hitching rides in not the female is a virgin. If she is – he stays, if not – he’s out of there.) hummingbird nostrils, mites in your hair follicles, mites eating up all the dead skin that sloughs off you in your home, large red velvet mites Q: How do these spiders move from in the desert, parasitic mites … they’re everywhere! area to another (disperse)? There are over 45, 000 described species of mites. Scientists believe A; In the autumn many of these spiders that we have only found 5% of the total diversity of mites. Mites are become aeronauts, migrating by what is believed to have existed for around 400 million years. commonly called ballooning. They let out silk until there is enough to be caught by the breeze to carry them off!! 26 11 Ticks Filmy Dome Spider (Neriene radiata) Western Black-legged Tick (Ixodes pacificus) is vector for Lyme disease (Family Linyphiidae) • Has to remain attached from several hours to a day • Cool association with Western Fence Lizards

Lyme disease is triggered by the host invasion of a spiral bacterium known as Borrelia burgdorferi, Other hard tick species, such as the American dog or lone star tick, may harbor this bacterium, but have not been implicated, to date, as human Lyme disease vectors (Other pathogens may be spread by these species, including tularemia and Rocky Mountain spotted fever.)

See you materials in Reptile Section for the story on how our Western Fence Lizards clean the tick of the bacterium! Not as common at MGP, but very prominent at Bouverie is the filmy diddome spider, whhtbiitd(hose sheetweb is an inverted cup (concave d)ithdown) with the spider underneath at the of the dome. The filmy dome spider is a riparian beast, and the further from the creek you go the fewer you see, larval ticks and the smaller each individual is. Webs are usually found on herbs or low bushes in cool moist places as in the borders of woodland paths or the shrubs fringing a shady stream. (It helps to have a piece of dark board or cloth to show these webs off.) Q: We often see the webs of these spiders along the sides of the Canyon Trail at Bouverie. What do the spiders look like?

A: The female is about 3/8 inch and slightly larger than the male . Abdomen is yellowish-white and marked with dark bands and stripes. Neriene hangs beneath the apex of the dome. When gets entangled in the web and falls on the dome, the insect is seized and pulled through.

Q: We alwayyps hear about female spiders eating their mates. Does this happen with filmy dome spiders?

A: No, unlike some spider species, in which the male is so tiny that the female does not even notice him, or others where the size of the genders is almost equal but the female has a penchant for eating the male rather than treating him as a mate, these spiders are experts at domestic harmony. HthitiktthiHowever, there is a trick to this … MlMales guar did immat ure females. When the female molts to maturity … the male mates immediately while she’s still soft. Males will fight over immature females that are being guarded. 12 25 Funnel Web Spiders Arachnida: Opiliones (Family Agelenidae) Harvestmen, Daddy Long Legs Q: What are makes those webs that look like funnels that we often see in the vegetation • In some places, harvestmen are known by around Monday-Tuesday Ponds and in the the name "daddy longlegs", but this name grasses in Garden Club Canyon? can also refer to two other unrelated arthropods: the crane fly and the cellar A: Funnel web weavers (not to be confused spider . with toxic funnel spiders of Australia) are • Harvestmen are found everywhere, but sometimes called ggprass spiders. Their webs are individual species don’t disperse very far, flat, often slightly concave, sheets narrowing to so harvestmen are good models for a funnel-tube retreat at one end. The retreat is biogeographic studies. open at both ends and the spider can usually be found sitting in it waiting in ambush with its front legs stretched out to feel vibrations • Differences between harvestmen and spiders : from its web. The actual feeding process • harvestmen appear to have only one body segment altkllways takes place ithtin the retrea t. These spiders are very ftfast – tthitry catching • (bd(abdomen w ithtith ten segmen ts an d cephlthhalothorax are nearljily joine d) one and you’ll see what I mean. The flat, horizontal layers of dry silk don’t so • no venom or silk glands much capture prey, as confuse them, allowing the agile funnel web spider to • a single pair of eyes in the middle of their heads, oriented sideways, rush out and pounce. These webs have been used as canvases to paint on, which cannot produce pictures and as band-aids to stop bleeding. • Legs continue to twitch after they’re detached. There are pacemakers located in the ends of the first long segment (femur) of their legs which send signals via the nerves to the muscles to extend Badumna sp. (Family Desidae) the leg and then the leg relaxes between signals. Some species will only twitch for a minute, others will twitch for hours. The twitching These spiders are all over the buildings at MGP. has been hypothesized as a means to keep the attention of a Look for their lacy webs. predator while the harvestman escapes. • Many species are omnivorous, eating primarily small insects and all Q: When you touch these webs they’re sticky kinds of plant material and fungi; some are scavengers. This range in a different way than orb weavers? What of eating habits is unusual for arachnids which are generally causes this? predators. • Use their second pair of legs as antennae to explore their A: Badumna (introduced from Australia) is a environment (eyes can’t form images). cribellate spider. It has a specialized spinneret • Most harvestmen reproduce sexually. Mating involves direct called – what else – a cribellum. The cribellum , rather than the deposition of a spermatophore. can have up to 40,000 sppgigots ppgroducing silk Sometimes the male guards the female after copulation. In in many thread about 0.00001 mm thick which is combed species the males defend territories. The females lay eggs shortly with special hairs on the hind legs (like carding after mating, or up to months later. Some species build nests for this wool) to produce fluffy, wooly silk (hacklebands) purpose. A unique feature of harvestmen is that in some species the with electrostatic properties. male is solely responsible for guarding the eggs. The eggs hatch after cribellum anything from 20 days to almost half a year. sem shthot o f crib iblltellate silk 

Q: What other spiders that we see are cribellate spiders?

A: triangle spiders, black widows, false widows and more … 24 13 Spider Reproduction Jumping Spiders (Family Salticidae) • Courtship involves lots of signaling (vibrational visual, chemical) and different courtship positions (see below) • Male sacrifice is less common than believed. • Pedipalps and epigynum act as lock and key (see page 23) • Male spigots for sperm web are not part of spinnerets • Use varying amounts of silk to protect eggs • Egg numbers vary between 1 and 1000 (cave spiders produce 1 big egg) • Developmental stages • Prelarva (immotile –usually in egg) • Larva (limited motility and leg segmentation) • Nymph – motile, venom (can feed), functional spinnerets • Generally, araneomorphs don’t molt past maturity; female mygalomorphs molt throughout life (shed spermatheca so need to get reinseminated) and males don’t molt once they’re mature. Q: Do they actually jump? • MtMaternal care (fema les o f some groups guard egg cases and A: YES! Th ey rai se the ir f ront legs in prepara tion an d thrus t w ith the ir hin d spiderlings) legs. Just before jumping, a spider will fasten a safety net to the substrate. Then it pulls its legs close to the body – et voila. If wolf spiders are the cheetahs of the spider world then jumping spiders are the leopards. With eyes so large they can resolve an image up to a foot away; jumping spiders stalk prey, then jump 10-20 times their body length to capture it! (They trail lines of silk when they jump(

Q: With such big eyes, does their courtship ritual involve visual cues? A: Yes. In fact they have some fairly elaborate courtship maneuvers. The cute spider above (Phiddipus johnsoni) will use both visual and chemotactile methods to court a female. If a male comes across a nest mygalomorph mating positions where the female is hidden, he’ll rub his front legs over the surface of the orb weaver mating positions • Male approaches female nest while his body oscillates up and down. If he sees her, he will approach • Often, male will create a from front, female raises her in a zigzagging dance, raising his legs, twitching his abdomen, and courtship line to the web prosoma, male inserts vibrating his palps. (The spider to the right performing a courtship dance is • Males are often a lot palps not P. johnsoni.) smaller than females Q: Do male jjpgpumping spiders ever face- off? A: Yes. However, threatening behavior is almost as ritualized as mating behavior (fighting rarely occurs). In more primitive jumping spiders, courtship and defense movements are the same. One thing that I used to d o w ith a littl e jump ing sp ider tha t sheet web mating position lived on my porch for several months was to crab spider mating positions bring a small mirror outside and hold it up. I • Male will often bind female Jumping spider with caterpillar could elicit defensive behavior by showing with some silk prey (up at Clem Miller) the spider his own reflection! 23 14 Wolf Spiders How Do Spiders Grow? (Family Lycosidae) Spiders have an external skeleton which they need to shed in order Q: Do these spiders make webs? to grow. Those spider bodies you see in your hose that are hanging out in webs and not moving are often the shed exoskeletons of the A: No. They are hunting spiders. One often sees them running in the actual spider. grass, especially in moist areas and near ponds and streams. They run just as well on the surface film of water! This is the cheetah of the spider world, running down prey by speed, rather than stealth. Since they chase down prey, they need good eyes Just imagine if your mother were a wolf spider … she would almost have eyes on the back of her head – at least on the side and top!!

Q: How do they find each other when it’s time to make babies?

A: A female will trail a -laden dragline behind her to lead male wolf spiders in the right direction. When a male “smells” her with his palps, he follows the dragline to the female. As he approaches, he will begin a courtship song and dance - waving his palps, raising and lowering his front legs, and vibrating his abdomen. In some species the males also vibrate their legs. These vibrations elicit a response in kind from a receptive female who responds with leg vibrations of her own.

You might see a spider scurrying around looking like it has three body parts … you might actually be watching a wolf spider carrying her egg sac. She wraps the egg sac with bluish-green threads and attaches it to her spinnerets. She carries the sac around until the sppgiderlings hatch. If one tries to take the egg case away, she will vehemently defend it. If it is taken, she will search for it for hours and even accept substitutes (paper balls, snailshells…). Mom assists during “hatching” by opening the rim of the cocoon. The newly emerged spiderlings climb on mom’s back andhd ho ldfld fas ttt to her a bdom ina lhl ha irs for 787 or 8 days. They live from their yolk supply and mom doesn’t eat during brood care. There may be as many as 100 tiny spiderlings resting on top of each other on top of mom! 22 15 Long-jawed Spiders (Tetragnatha sp. usually) Crab Spiders (Family: Teragnathidae) (Family Thomisidae)

Crab spider using thistle spine to “store” prey Q: Why are they called crab spiders? A: Look at them! They have long front legs and are able to move Q: We often see nearly horizontal webs with open hubs near sideways, frontward, and backwards, like a crab. With the small back water at ACR – what spider makes them? legs the spider holds itself steady. The front legs, which are held outwards, are more powerful, and grab unsuspecting flower visitors A: These spiders have a few common names – long-jawed, with amazing speed, while administering a poisonous bite. Prey is streamside, stretch, and marsh spider are a few of them. They’re mostly eaten on the flower and is sucked dry through tiny holes, leaving called long jawed due to their large chelicera, streamside and marsh because they are riparian and wetland spiders and stretch because behind an almost complete exoskeleton. they have an elongated body form. They the sit with six legs extended Q: Why do we often find these spiders in or around flowers? parallel to their bodies, often on a grass blade or reed, holding on with their short third pair of legs, and blending into the vegetation. Webs A: They’re sit-and-wait predators. They camouflage themselves to are often horizontal or close to it, rather than the typical near-vertical blend in with their background. When a pollinator or other visitor orientation and is missing the central hub. comes to the flower … wham! … It’s spider food. Some female crab Q: Are there any adaptations Tetragnatha has for living near spiders are even able to change color. New information shows us water? that bees PREFER flowers with crab spiders in them. It’s thought that this is a result of crab spiders reflecting UV light in a range A: They are able to run over water using a diagonal rhythm with their 1st desirable to the bees!! (There are even some crab spiders (not at and 2nd pair of legs and dragging legs 3 and 4 passively behind them. MGP) that disguise themselves as perfect imitations of bird poop Interestingly, Tetragnatha can run faster on water than it can walk on (smell and look) with a white blobby web underneath them. Bird dung land! spiders prey on the that feed on bird poop) XXX RATED: Tetragnathid Sex: The male has special spurs on his chelicerae. When courting, the male and female approach each other with jaws agape. Their front legs come in contact with each other and male pushes female’s legs apart and employs the special spurs on his jaws to lock into opposing spurs in hjher jaws … keep ing hjher jaws ou tft of comm iiission and facilitating non-fatal sperm transfer. The trouble often comes when he leaps backwards to (Hunt for them in poppies … Look at that safety. This leap is not always successful. camouflage!) 21 16 Comb-footed Spiders (Family Theriidae) Missing Triangle Spider Black Widow, False Widow, House Spider (Zygiella sp.)

Q: What is the “missing” part of the web all about?

A: Zygiella constructs her retreat at the peak of the “missing” part of her western (black) widow house or domestic spider web. It’s easy to find the spider if (Latrodectus hesperus) (Achaearanea tepidariorum) you look closely because she has a signal line attached from her Q: Why are they called comb-footed retreat to the center through the spiders? “missing” portion of her web. A: They have a comb of serrated bristles (setae) on the tarsus of the fourth leg (too small to see without a scope). The combs are used to throw sticky silk over prey. Theridiids may wrap their prey in silk before applying false widow (Steatoda sp.) a poisonous bite (wrap attack. The wrap attack allows theridiids to delay Q: Where can you find the missing triangle? direct contact with prey until it is safely immobilized. A: Look on the railings and around buildings. Zygiella is an introduced Q: The webs of these spiders looks like a messy tangle. Is there a spider (from ) and does well around human habitation. particular name for it?

A: These webs are officially cobwebs! They are a remarkable tangle, with a number of taught vertical lines attached to the ground or surrounding substrate. The drawing to the left is what Prey is snared when they bump the loosely attached taught-lines and are happens when you give a whipped up into the tangle! (There is a great tale of an arachnologist watching a missing triangle spider caffeine house spider subdue a mouse: at 2pm silk was thrown around tail; by 4 pm … makes you think … the mouse could barely touch the floor; by 9 pm the mouse was 1 ½ inches above the ground; by the next morning, the mouse was dead.) These are cribellate spiders like Badumna and the triangle spider (see page 9).

Q: What type of toxin does the black widow have?

A: The toxin is a neurotoxin. It causes ppgain throughout the bod y,,y, nausea, dizziness, sweating, muscle spasms. The anti- are good. These are not aggressive spiders. Most injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched. Some bites may result when a spider mistakes a finger thrust into its web for its normal prey, but ordinarily intrusion by any large creature will cause these spiders to flee. 17 20 (Family Araneidae) Triangle Spiders Debris Spider (Cyclosa sp.) (Family Uloboridae)

Q: People often get confused The triangle between the debris spider and spider is a the condo (or labyrinth) spider. member of the What’s the difference? only family of spiders A: The debris spider has a known to lack single orb web with a string of venom glands debris down the center (this is (Uloboridae). also a stabilimentum like the zigzag in the garden spider webs). The debris spider hangs out in the middle of this string of debris. The condo spider’s web has a messyyp part and a perfect orb part as well as a retreat in the messy part. Q: Where’s the rest of the web?? Q: What does the debris spider use to make its “string of debris” or A: Triangle spiders are not in the orb weaver family (Araneidae). (They’re stabilimentum? in the Uloboridae family.) Though they spin webs that look like someone cut a pie out of an orb web – it’s different from “orb weaver” webs in several major A: The debris consists of plant material, as well as prey items (old and ways: new) and shed skins. When the spider is ready to lay eggs they are • The spider is actually part of her web! added to the line of debris. • The web contains no sticky silk. Triangle spiders are cribellate spiders; meaning they produce a special kind of silk that is very wooly and Q: What does the debris spider has electrostatic features to help it cling to prey. actually look like? Q: What do you MEAN the A: There are actually 4 species of debris spider is part of her web? spider (Cyclosa) in the bay area. MGP’s most common one is Cyclosa conica, A: The spider attaches a thread named for the cone-like projection on the to some solid object and a end of its abdomen. I teased one to the tension thread to the apex of top of her web to get a photo. the web. She is a living part of her web! She holds on at the point of attachment taking up slack and creating tension. When a prey item of the appropriate size stumbles into (These spiders will vibrate their webs when you disturb them just like her web, the tension in the cellar spid ers. Wh a t m ig ht be a reason they do this ?) attachment line is released by the spider causing the web to collapse on her victim. 18 19 Cellar Spider Orb Weavers (Family Araneidae & others) (Family Pholcidae) Orb webs are made up of three elements: (in houses, around buildings, in pond cabinet, fire hose cabinets, etc.) 1. radial threads (converging to a central spot – the hub) 2. frame threads (provide web perimeter and insertion sites for radial threads 3. catching spiral (studded with glue droplets)

The frame and the radii provide a stable construction that is also good for transmitting vibrations used in prey capture and mating. The sticky spiral is also veryyp elastic. When preygy struggggles the energyyyp is absorbed by the spiral and less damage is made to the web.

The number of radii vary from species to species (Araneus diadematus has 25-30; our long-jawed spider only about 18).

Construction of orb web: female with egg sac 1. Star t w ith a hihorizont tlthdal thread by le tting silk out until it is carr ie d by a dra ft vibrating in web and catches on something. Bite through this, grasp the cut thread and Q: How can these spiders be distinguished from the common house move to the middle, reeling off a new thread. spiders or cobweb spinners? 2. Descend vertically until the thread can be fastened to a surface, creating a Y-like structure. A: They can be distinguished from house spiders by two behaviors: (1) they 3. Create radial threads (a complicated process) and add frame lines, carry their whitish egg cases in their jaws (see above), and (2) they d osucho such deciding at hub which sector the next radius will be placed. rapid pushups when disturbed that they appear to vibrate in circles in their 4. While placing radii, connect them with a few narrow circles in center of web. (They will also shake their webs to hasten entanglement of prey.) I highly web, eventually creating and auxiliary spiral tying the radii together. recommend you do this with the kids … there are always a few in the corners of 5. Starting at periphery of web, use the auxiliary spiral as a guide, lay down the display hall. sticky threads of catching spiral, attaching them to radii and removing the auxiliary spiral. Males live in the same webs as females and look like them except for their swollen palps (see page 23).

Q: These spiders are called sometimes called daddy long legs. Aren’t there other things called daddyygg longlegs too?

A: Yup. Daddy longlegs “officially” refers to a group of spider-like critters called Opiliones. Opiliones also have eight legs BUT they have only one distinguishable body part. We see them i n the so il, un der logs, in the an d around the fire hose cabinets and other places.