Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
Please send in your best wildlife photos. I have a reasonable backlog, but it gets depleted quickly.
Today’s arthropods are from regular contributor Tony Eales from Queensland. His notes and IDs are indented; click on the photos to enlarge them.
I’m afraid I’m going to spam you with a few because I’ve had a good couple of weeks finding new weird beasties that I’m keen to share.
There’s been a lot of new life of late in the rainforest, with the spiders in particular producing slings (that’s what we spider lovers call ‘spiderlings’)
My favourite rainforest cellar-spiders, Micromerys raveni, are producing eggs and babies, and I managed to capture three stages in one afternoon. A gravid female, a female with eggs and a female with newly hatched slings on her back.
Also, at the tips of some palm leaves are folded tetrahedrons held together with silk. If you can carefully open them a crack there is a mother long-legged sac spider, Cheiracanthium sp. with her newly hatched young.
There seems to be no season to the little green jewel-like Chrysso sp.: I rarely see one without a clutch of humongous (relative to the mother) eggs.
I also love to find these tiny white Theridiids, currently undescribed but will probably go into the genus Meotipa. Looking at the developed eggs I suspect that spider eggs don’t so much hatch as just develop into slings. Does anyone know?
Finally, an unknown Theridiid mother inside a cured leaf retreat with her brood.
The photo tank is running low, so please send in your good wildlife photographs.
Today’s contributor is a regular, Mark Sturtevant, with some lovely arthropod photos. His notes are indented.
This is the last installment of pictures taken last Spring when I was visiting the Phoenix, Arizona area for several days before attending a fancy teaching conference.
First is a picture of a buckeye butterfly (Junonia coenia), a species that is widespread in the U.S., followed by a white peacock butterfly (Anartia jatrophae), whose range is restricted to southern states so it was new to me. I saw plenty of both on this trip, but they were easy pickings in the Desert Botanical Garden.
Next is a male western pondhawk (Erythemis collocata). Very similar to the eastern species back home, but eastern pondhawks have white cerci (the paired appendages near the tip of the abdomen), while the western species have black cerci.
I spent much time in the Tonto National Forest. This national forest covers an enormous part of the state, and in its northern range it is indeed forest, but in the Southern range it is of course Sonoran desert. Central to this region is the Salt River, which is wide but shallow (I could easily wade across it), and it is sustained by periodic releases of water from a dam. It is not unusual to see herds of wild horses at the river, and indeed I saw a large herd some distance away that was being surveyed by another photographer who had a lens that was the size of a fire hydrant. Here is a lovely video that features these animals, and you can see some of the Sonoran desert scenery as well.
Rubyspot damselflies were hoped for and found at the river. There is more than one species that is possible, but these are most likely the American rubyspot (Hetaerina americana). The first are females, and the last is a male. The males were firmly staying out on the water so I had to wade out and basically lie prone in the river to photograph them. It was like a warm bath.
Next is a beautifully camouflaged pallid-winged grasshopper, Trimerotropis pallidipennis. Had to lie down on the hot ground for that one!
My last day goofing off was spent at the Hassayampa Forest Preserve that was north of Phoenix. This was a long drive to a higher elevation, so that the Sonoran desert was displaced by grassy meadows and deciduous forest. Part of the time in this park was spent searching for Dangerous Things by lifting up loose tree bark. This being Arizona, it did not take long! The next picture shows a western black widow spider (Latrodectus hesperus). The link provides some information about the various species of ‘black widows’ in the U.S. In addition there are a couple other species of widows that we have.
Shortly after that I found what I was really after: an Arizona bark scorpion (Centruroides sculpturatus). This was a very satisfying end to the adventure!
And with that, it was time for the long drive back across Phoenix to the airport to drop off the rental car and experience the surreal plunge of being in civilization and mingling with people.
Tony Eales from Brisbane has sent us a collection of mixed arthropod photos. His notes are indented:
I just thought I’d throw together some oddballs for fun.
First, a tiny little mite known as a whirly-gig mite family Anystidae. These guys are so small and fast that I rarely attempt to photograph them even if I see one. However this one stopped for half a second and I just managed to get the focus.
Next, a particularly pretty planarian worm called Australopacifica regina, found in the local subtropical rainforest under a log.
This is one of the cup moth or slug moth caterpillars. Calcarifera ordinata. The stings are said to be particularly fierce. Happily so far I remain un-stung, touch wood (actually don’t touch anything in the bush, it probably stings or bites, just take photos).
Next a few spiders. First, an undescribed member of the genus Celaenia. This genus generally imitate bird droppings though this one not so much. Still, it l doesn’t look very appetising.
Second an ant-mimicking jumping spider. Not as convincinga close-up as the more well-known Myrmarachne species, but from above at a glance, it’s still very ant-like. This one is genus Ligonipes sp: .‘white brows’. A very common but as yet undescribed species.
The last spider is an Oonopid aka goblin spider. Maybe, genus Grymeus. I’ll know more later as there’s a person at the Qld Museum currently working on the family and I’m sending the specimen in to go into the collection. For fun I’ve added a picture of the spider in the test tube. See if you can spot it.
I picked up something fairly rare the other day, a species of lace bug, Tingidae. To me it looked like the fairly common pest known as the Azalea Lace Bug Stephanitis pyrioides but the experts said “Oh no, The shape of the hemelytron is distinctly different. This is an Australian endemic, Lepturga magnifica. In any case, it’s an interesting looking bug.
Weevils are so diverse and there are some extreme variations on the weevil bauplan. This is one of the odder ones Rhadinosomus lacordaireei or Thin Strawberry Weevil.
Last but not least, a weird offshoot of in the lacewing Order Neuroptera, a Beaded Lacewing in the family Berothidae. These are unusual within the Neuropterans for having particularly hairy wings. The one pictured is Stenobiella sp. The larvae of these lacewings live in termite mounds, apparently unmolested, snacking on a passing termite when hungry. Wired did an article on how the larvae have been observed to paralyse the hapless termite with termite-stunning farts
Please send in your good wildlife photos (roughly ten to a dozen if you have that many, though fewer are also welcome). And please supply locations and Latin binomials. Thanks! Today’s batch comes from regular Mark Sturtevant, whose comments are indented. Note that in his first sentence Mark says, “I do me”!
Here are more ‘Arthropodian’ pictures from two summers ago. It is what I do.
The first picture shows one of many of our very quiet ‘housemates’. Cellar spiders will frequently return to old prey to scratch out a meager living, and will even accept dead and dried prey. They are very welcome to all the carpenter ants they can find. It is described that in the U.S., cellar spiders who live in homes are almost always one of three introduced species. This seems to be Pholcus phalangoides. The white patch on the abdomen is the cover for one of her respiratory openings. Spiders breathe through a pair of ‘book lungs’, which are stacks of thin respiratory membranes in the abdomen.
Late in the summer I have been regularly venturing outside at night in hope of photographing the male snowy tree crickets who loudly announce their presence from our bushes. It turns out that they are surprisingly hard to pinpoint, since they seem to ‘throw their voice’, and so I usually come away cricket-less. But here I managed to surprise this angle-wing katydid nymph (probably Microcentrum rhombifolium). The adults of these large katydids are also heard calling at night, but adults generally stay well out of reach in the trees.
The parasitized hornworm caterpillar in the next picture comes with an amusing story. I was out in a park one day when this professor I knew from work abruptly emerged from a trail carrying this branch with the caterpillar on it. He had been wearing the leafy branch on his head to keep away mosquitoes and was later surprised to see this caterpillar hanging down right in front of him! He gladly relinquished the find, and here it is. This should be a larva of one of our clearwing sphinx moths, although this one has defied identification beyond that. The white objects are the cocoons of parasitic Braconid wasps. The caterpillar of course is doomed.
In the next picture is a lovely moth that is clearly an excellent wasp mimic. It was sitting out in our back yard, and represents one of the many occasions where I find something in the back yard and have to drop everything to grab a camera. This is the red maple borer moth, Synanthedon acerrubri, and it may have come from a red maple tree that we have.
We continue with a couple more Lepidopterans. I generally no longer bother with monarch butterflies (Danaus plexippus), but this sleeping one was letting me get very close to it. I liked how the light was working, and so I ‘bothered’. The flower head that it is on is teasel, an invasive species. The plant is much loved by butterflies and other pollinators, but now there is so much of the stuff that I am well at the point of not liking it.
The margin of a certain lake frequently turns up butterflies that sit near the water to imbibe the salts and amino acids from the wet bare ground. The next picture shows a perfect red-spotted purple butterfly (Limenitis arthemis) that was on the shore. The colors really pop with the camera flash!
In the woods I can usually find one or two of the species shown in the next picture. From a distance they look like a small wad of fluff on a tree trunk, only this little bit ‘o fluff will be slowly moving and has a set of very long mandibles. This is a species of debris-carrying ‘aphid-lion’ larva, and so is the larval form of one of our green lacewings (genus Chrysopidae). The debris that it is carrying is for concealment and protection from its own enemies.
The next picture is of a leafcutter bee (genus Megachile) at an artificial bee house that was being kept in the public garden at a local park. I should get one of these bee houses for yard, as watching all the drama taking place was very absorbing! Leafcutter bees are solitary, and females will raise their larvae in wood or earthen tunnels. They can raise several larvae at a time in separate pollen-filled chambers that are divided by pieces of leaves. This old video tells their story in charming detail: https://www.youtube.com/watch?v=k2AWCrePaZk What I am now curious about is how the new brood of bees exit the tunnel, since the ones developing deeper in a tunnel would surely be older. How do they emerge without harming their younger siblings who would be nearer the exit?
Finally, during a particular window of time in the summer I will frequently come across the strange bee that is shown in this last picture. It is also a leafcutter bee, but it is a kleptoparasitic species (Genus Coelioxys). That means the females will lay eggs in the nests of other leaf cutter bees, and its larva will eat the food of its host. They are always very alert, and so this one had to be photographed at some distance, so the picture is heavily cropped.
A new paper in Nature by Jean Vannier et al. reports the unusual finding of a parade of trilobites—a group of the ancient arthropods—apparently killed and fossilized while walking in tandem, like an invertebrate conga line. They’re 480 million years old, from the Lower Ordovician, and were found in Morocco. (The paper can be seen by clicking on the screenshot below, the pdf is here, and the reference is at the bottom.) This weird lineup of trilobites suggests some kind of collective behavior—the first such find documented by paleontologists. But what kind of behavior? The authors have two hypotheses, and I’ll discuss them briefly.
First, some photos of the species, Ampyx priscus, which had a hollow “glabellar spine” in front and two “librigenal spines” going backwards. The white scale line is 1 cm long, so these things were, including the front spine, about 6 cm (2.3 inches) long. The spines might have enabled the trilobites to sense each other and thus maintain contact while moving in line, much as spiny lobsters do when moving across the sea floor in line as I show below. (Any “communication” must have been tactile as these trilobites were blind.)
All captions are taken from the Nature paper. Here are the individuals at hand, with some close-ups of their spines:
General morphology and parameters of the raphiophorid trilobite Ampyx priscus Thoral, 1935, from the Lower Ordovician (Upper Tremadocian-Floian) Fezouata Shale of Morocco (Zagora area). (a–d) BOM 2481, overall morphology and details of genal spines. (e) Parameters used in measurements. (f,g) MGL 096718, genal spine showing internal mineralized infilling. (h) AA.OBZ2.OI.1, transverse thin section through right genal spine (see general view in Supplementary Fig. 8d). (i) MGL 096727, genal spine. (j) ROMIP 57013, external mould of glabellar and genal spine showing longitudinal ridge. a–d,f,g,i,j are light photographs.
Here are the fossils of the lined-up trilobites, which are remarkable, along with schematics showing the nature of the relief of the stone in which they were preserved.
Linear clusters of the raphiophorid trilobite Ampyx priscus Thoral, 193531, from the Lower Ordovician (upper Tremadocian-Floian) Fezouata Shale of Morocco (Zagora area). (a,b) AA.TER.OI.12 (see Supplementary Fig. 2a). (c) MGL 096727 (see Supplementary Fig. 5a). (d) AA.TER.OI.13 (see Supplementary Fig. 2b). (e) BOM 2461 (see Supplementary Fig. 2f). (a,e) are light photographs. Line drawings from photographs. Segmented blue lines in (b–d) join the central part of occipital rings of trilobites. Red arrows indicate the position of polished section in Fig. 3. Abbreviations are as follows: (x), Asaphellus aff. jujuanus (asaphid trilobite); (y), juvenile asaphid trilobite. Scale bars: 1 cm.
Here’s a video of spiny lobsters migrating in line, much like these trilobites:
So why were these ancient arthropods marching in line? The authors reject two hypotheses. First, that they were “mechanically accumulated along linear submarine reliefs (e.g. between ripple marks)”. This is the hypothesis that they were blown into grooves in the ocean floor and accumulated there, explaining the lines. That, however, doesn’t explain the consistent alignment rather than some being blown in backwards. The authors reject this because there is no indication from the fossil strata themselves that there were these reliefs.
They also reject the hypothesis that these trilobites were lined up in burrows underwater and then trapped and killed by sediments. Their rejection is based on the absence of “any colored outlines or disturbances in the sediments surrounding trilobites.” I’ll trust the authors on this since knowing how to detect ancient burrows is above my pay grade.
Rather, the authors proffer two hypotheses to explain the alignment. The first, shown on the left below, is that there were underwater storms or currents that made the trilobites orient in one direction, and then they “found” each other by tactile signals (or perhaps also by chemical signals), forming a line that served a protective function. As the authors say, “Such mechanical contacts [as in the lobsters above] appear to be essential for group cohesion and for optimal coordinated locomotion.” Marching in a line reduces drag, saves energy, and, say the authors, “reduces the probability of detection and attacks by predators by creating confusion in their [predators’] visual perception.”
The second hypothesis, shown on the right below, is that the trilobites emitted chemical signals like pheromones as a way of detecting each other and coming together for sexual reproduction, with the lines presumably indicating a migration toward spawning grounds. As the authors note, both explanations could be operating together.
Two non-exclusive hypotheses to explain the linear clusters of Ampyx priscus from the Lower Ordovician of Morocco. (a–c) Response to oriented environmental stress (e.g. storms); hydrodynamic signal (higher current velocity represented by white arrows) received by motion sensors triggers re-orientation of individuals; mechanical stimulation and/or possible chemical signals cause gathering, alignment and locomotion in group. (d–f) Seasonal reproductive behaviour; chemical signals (e.g. pheromones; see red circles and red arrows) cause attraction and gathering of sexually receptive individuals (males and females) and migration to spawning grounds. The alignment of individual may have been controlled by mechanical stimuli (as in a–c). Olfactive and mechanical sensors were probably located on the antennules (pink areas 4, 5), and genal and glabellar spines (green areas 1–3), respectively. The exact location of mechanoreceptors is uncertain (possibly on high-relief exoskeletal features such as the glabella).
As for how they were buried together, that’s a bit of a mystery since trilobites, when stressed, are supposed to have curled themselves into balls like modern isopods, and these didn’t do that, as you can see above. Here’s one scenario that explains the successive strata in which lines of trilobites were buried.
First, subject to periodic storms that disturbed the waters, the trilobites joined up in a Big March. (Or, as I noted above, they could be marching for mating!). Then, the storm quickly deposited sediment atop the marching trilobites, preserving them in situ. There could have been two other events that preserved them quickly: “water poisoning,” like the release of hydrogen sulfide gas or, more likely, the upward movement of oxygen-poor (“anoxic”) sediments, which killed the trilobites quickly from lack of oxygen as well as protecting the carcasses from scavengers.
You can see one instance of preservation in panels a-c below, and then another line of trilobites forming in panel “d”:
Scenario to explain the in situ preservation of the Ampyx linear clusters from the Lower Ordovician (Upper Tremadocian-Floian) of Morocco. (a) Deposition of a distal tempestite (event layer 1). (b) Epibenthic (e.g. trilobites) and shallow endobenthic (e.g. possible worms) organisms settle and generate bioturbation above red-ox boundary. (c) Second storm event layer entombs epibenthic fauna in situ; red-ox boundary moves upwards (white arrows). (d) New faunal recolonization. According to Vaucher et al.34, distal storm deposits are relatively thin (less than 5 cm) and consist of a waning (base) and waxing (top) phases (subdivision not represented in this diagram), and depositional environment is that of the distal lower shoreface with a possible water depth of approximately 30–70 m. Bioturbation is based on polished and thin sections (Fig. 3 and Supplementary Figs 8 and 9). Abbreviations are as follows: bt, bioturbation; tr, trilobite group (Ampyx); trc, trilobite carcasses (Ampyx); w, worm; wsi, water-sediment interface.
Now much of this is speculative, as it must be with limited information about what happened 500 million years ago. But it certainly looks as if, like spiny lobsters, these trilobites were marching in line, probably following each other using tactile cues. And so we get a rare window on invertebrate behavior from the distant past.
Reader Vampyricon called my attention to this video about a crab unknown to me: the sand bubbler crab. It eats sand, extracts the organic material, and then spits out the sand in a series of little balls. Moreover, as Wikipedia notes,
In each burrow, the crab waits out the high tide in a bubble of air.
These are pretty amazing animals, and Ze Frank, as usual, gets the biology right.
Tony Eales from Brisbane sent us some lovely photos of arthopods, including some great examples of mimicry and camouflage (“crypsis”). Tony’s captions are indented.
Some mimicry and a few other random arthropods.
Three shots of a wraparound spider, Dolophones sp. These are small, only about 8mm across and fairly common, but rarely seen for obvious reasons. I find them mostly in the late afternoon as they start to build their web for the night. When building the web they just look like any other small orb-weaving spider, but when they see you approaching they scurry up a silk-line to the nearest twig and virtually disappear. As you can see in the third picture, when not all folded up in camouflage pose they display quite a bit of colour.
The ones I normally see have flattened dome-shaped abdomen but I knew there were ones out there with these weird turrets on their backs and had been wanting to photograph one for ages. Evolution is weird.
Next is a Hangingfly Harpobittacus sp. Hangingflies are in a separate order of insects Mercoptera along with Scorpionflies. We don’t have a lot of species diversity in this family in Australia but do have a lot of diversity at higher levels, with two families being endemic. Hangingflies are famous for their elaborate mating rituals in which the male captures prey to present to the females. I hope to observe this one day.
This female Clear-wing Persimmon Borer moth (Ichneumenoptera chrysophanes) is so far the find of the season for me. I have never seen such a striking wasp-mimicking moth.
The model is probably something like this Ichneumenon wasp Xanthopimpla sp.
And lastly just a little cutie. A very tiny Sandalodes sp. jumping spider with a tiny katydid nymph as prey. [JAC: Doesn’t it look excited?}
Today Mark Sturtevant gives us a batch of lovely insect and arthropod photos from Hawaii. Mark’s notes are indented:
Over a year ago, my family and I visited Maui for a ten-day vacation. I of course brought my camera and I used every opportunity to photograph arthropods.
We spent several days in Kihei, which is a lovely but touristy town on the southern coast. But true to what everyone says about Maui, it still felt very small and laid back. A short drive north from there along the coastal highway takes one to the Maui National Wildlife Refuge. This is one of many maintained natural areas, and I visited the site several times.
One of my first finds there was the large Hawaiian garden spider (Argiope appensa) shown in the first picture. These striking spiders are indigenous to several islands in the Pacific, and they were everywhere on Maui. Most of the time the spiders would be hanging the ‘wrong way’ with only their ventral side being easily viewed. But if you reach around the top and give them a light tap on their back they usually flipped to the other side of the web and posed for pictures. Next is a tiny male of this species. These were generally hanging out near the females in an accessory web. Like most orb weavers, male garden spiders are very small.
Another common arthropod was a very large kind of grasshopper, shown in the next picture. This is the gray bird grasshopper (Schistocerca nitens), which is a kind of locust that also lives in the southwestern U.S. where it can be a pest. On the Hawaiian islands, however, it has become a more serious pest and there it has been known to swarm. Although many species have been introduced to the islands by humans, this locust probably got there on its own. This individual was unusually low in energy, probably because of its serious mite infestation. The other ones that I found were very alert and I could not get near them.
The jumping spider shown in the next picture is Platycryptus undatus. This is a species that we’d commonly see at home! But I soon got used to this sort of thing. Some arthropods were exotic (to me), while others were also common on the mainland.
The head groundskeeper at the wildlife refuge was named Sammy, a very enthusiastic tour guide of the refuge. As I do when talking about arthropods, I soon told Sammy about my special interest in dragonflies. He explained that the best place to find them was nearby at a nearby wildlife refuge that ran along the coastline. What he described to me seemed unlikely: that this refuge had a beachfront boardwalk that runs through marine wetlands, and that dragonflies are often numerous there. How could that be? Dragonflies require freshwater to grow up! I set out at my next opportunity to check it out.
Here, seawater from high tides and storms are driven inland to sustain many acres of salt marshes. Farther inland, the salt water meets fresh water run-off from the area farms and nearby coastal mountains. The sky was fairly swarming with dragonflies! Their larvae must live in this place by staying farther inland, in parts of the marshes not penetrated by salt water. In the shallow water beneath the boardwalk were schools of colorful marine fish which could be at home among corals, while flying above them were numerous dragonflies. I identified green darners, wandering gliders, and the lovely roseate skimmer (Orthemis ferruginea), a new species for me. The next two pictures show roseate skimmers. The first is a male, followed by a female.
At several places along the boardwalk one could access the oceanside beach, and here too were remarkable numbers of dragonflies that were contesting for perching sites on driftwood within easy reach of ocean waves. It was amazing. Thank you, Sammy!
Finally, during my first visit at the wildlife refuge I found this interesting praying mantis nymph that is shown in the last two pictures. This is the Asian mantis, Hierodula patellifera. It is also known as the ‘giant’ Asian mantis, and that is puzzling since I would say it would be better called the ‘pretty big’ mantis. The last picture shows that a mantis does not always look dignified.
Tony Eales of Australia sent some diverse but inclusive photos, including insects, plants, fungi, mammals, and arachnids (mites). His notes are indented:
A more or less random grab bag of images. First is the law of the jungle in my back yard. One of our native crab spiders Boomerangia dimidiatacaptured a soldier fly Odontomyia sp.
Next is an Australian Tailed-Emperor (Charaxes sempronius) caterpillar that I found on a wattle phyllode. I say phyllode rather than leaf as this species of acacia bush has true leaves only as a seedling and what I always thought were its leaves are actually flattened stems. You can tell because rather than having a central vein it has several parallel veins.
Another of the weird plants that I saw in Western Australia earlier in the year was this odd-looking sundew (Drosera platystigma); the plants were tiny, less than a centimetre across.
I’ve been trying to get out more with the arrival of spring and found this beautiful dragonfly, the Tau Emerald (Hemicordulia tau), sitting peacefully in the cool morning air.
A classic Australian shot of an Eastern Grey Kangaroo (Macropus giganteus) and joey that I saw at a campsite in the mountains near where I live.
Something I’m trying to find out more about at the moment are entomopathogenic fungi. I found this specimen that had devoured a tiny beetle. I’m informed by an expert at the Department of Agriculture and Fisheries who is into these things that it’s probably an undescribed Ophiocordyceps sp.
I more often see the larvae of sawflies munching away on leaves in groups. It’s always interesting to see the adults as they really look like nothing else in the flying insect groups. This one is Pergagrapta polita.
And finally one of the giant mites that I encounter in the bush. I think they must be very active at the start of spring as I’ve been seeing them turn up on Facebook identification groups accompanied by “what the hell is this?!” messages. This is a Rainbowia sp., and it’s about 10mm long, which is huge for a mite. The adults prey on invertebrates and the younger stages are tick-like ectoparasites on many larger arthropods like grasshoppers and huntsman spiders.
[JAC: You can see from this picture why mites are grouped with spiders in the class Arachnida.]
Thanks to the readers who have sent me photos in response to my plea. I still need other ones, though, so send in your good photos—and thanks!
Today’s photos come from Mark Sturtevant, who says, “The pictures tell a story that is only a tiny bit sad.” His narrative is indented:
I have always been obsessed with insects and spiders, and while growing up I would often keep them as pets. Caterpillars and cockroaches (and snakes) were not allowed, by parental decree, but anything else was fair game. Somewhere around the age of 12-14 I had a pair of ‘bold’ jumping spiders (Phidippus audax), male and female, and I knew from somewhere that their courtship and mating was interesting to watch. So I decided to place them near each other on my bed to see what might happen.
Upon seeing the female, the male immediately went into this remarkable leg-waving and palp-bobbing dance, and hesitatingly advanced toward the lady. The female also advanced toward the male. This was exciting! The male continued to dance and wave. The female continued to move toward the male (but was not waving back). The male started to back away. The female kept coming. The male turned to run … but the female… murdered him. I still feel badly about this appalling outcome.
It’s many decades later, and I have once again come into possession of a pair of bold jumpers. In the first two pictures I show the male (“I’m a lover, not a fighter”), and then the female (“She’s a maneater”). If I put these together, would history perhaps not repeat itself?
I wanted to try it out, but a more cautious approach seemed advisable! So I made a little box out of microscope cover slips, and put the female into it as a kind of ‘reverse shark cage’. She was first presented to the male this way to safely gauge her predisposition toward cannibalism. The next two pictures show the result. The male immediately approached, signaling his interest, and lo! The female waved back!
Following that, with heart thumping, I separated them and after a time the cage was removed so they were in the same space without any barrier. Again, the male approached, dancing away, and the female also waved back, as shown here.
Now it would be nice to next show explicit pictures of mating spiders at this point, but that is not how this experiment turned out. As shown in the last two pictures, each time the two were presented to each other, the female would ultimately turn and flee after a few moments. I tested this several times, over a few days, and this was always the result. I don’t know why, but perhaps her suitor was “wrong” somehow. These are somehow the saddest pictures I have taken. He always looks so dismayed! But at least he survived to dance another day.
If any readers know of appropriate French phrases for this sort of thing, perhaps they could share them.
