Syrphus torvus (from Greek for “fierce”) has hair growing out of its eyes (shown here). This is not uncommon for insects, but most require a microscope to see them. The hairs act like eyelashes, keeping dust off the lenses. By lowering wind on the surface by 90% they reduce evaporation.[doi:10.1140/epjst/e2015-50094-x] They also act as airflow sensors: shave them off and honey bees fly slower and report the wrong direction relative to the sun in their post-flight dance.[doi:10.1007/bf00367159; doi:10.1007/BF00367159]
2023-07-13 Les Karellis, France
Normally nectar drinkers, the wedding day calls for a heartier meal. Guys are expected to catch an insect to present as a nuptial gift. Food in hand, he flies into a swarm to hook up with a willing female. If his gift is acceptable they retire to a nearby leaf, and a few minutes later (2.94 ± 0.84; n=27) it is back to the dance. Only a bit of the gift is consumed each time but after several rounds it’ll be sucked dry and rejected. Time to catch another gift, which may happen to be a rival male. Some guys cheat, and instead of an insect they will pick a bit of willow fluff to mold into a ball. This is usually rejected, but try enough times and you might get lucky! [DOI:10.1111/j.1469-7998.1999.tb00987.x]
Although catching insects is hard work, the alternative used by E. trigramma is harder. Males of this species convert some of their body mass into liquid as a gift for the female. After several rounds, each with a different female, he becomes emaciated and dies. By the end of the mating period most of the males are gone, and those guys that were rejected earlier start to look pretty good.
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
An orb weaver rather than a jumping spider, Aculepeira ceropegia spins her web and waits for her prey. Webs are recycled every few days giving her some water and veg (pollen makes up ¼ of the diet for juvenile spiders).[DOI:10.1371/journal.pone.0082637] The much smaller male mostly doesn’t bother with a web. Instead he will reel out some silk and let the wind carry him in search of a mate (“ballooning”).
Gravity plays a role in web building. Various schemes have been devised to test this, such as attaching a weight to the spider or rotating the box during the build. You can even send them into space, but be sure to feed them! They don’t build nice webs when they are dying of hunger and thirst (1973 Spacelab). Live fruit flies seemed like a good idea, until the population explosion covered the observation windows (2008 ISS). The reprise (2011 ISS) went much more smoothly, with characteristic asymmetric webs constructed by golden silk spiders (RBD #483) when the lights were on. In the dark they lacked direction and only built circular webs.[DOI:10.1007/s00114-020-01708-8]
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
Jumping spider species (Salticidae) can leap up to 10 cm,[1] deploying a drag line for control and braking. For the full bungee experience, they anchor their line, snapping back with their prey dangling in the air. This even works in zero gravity, after a few bumps on the head during trial-and-error learning.[2] A single meal is enough to last them several days,[3] or the many months of hibernation for those with 2-3 year life-cycles.[4]
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
[1] Hill, D. E. 2018. The jumping behavior of jumping spiders: a review (Araneae: Salticidae). Peckhamia 167.1: 1-8. [2] Hill, D. E. 2016. Jumping spiders in outer space (Araneae: Salticidae). Peckhamia 146.1: 1-7. [3] Bruce, Will. 2024. How often to feed your jumping spider. TheSpiderBlog [4] Matsumoto, Seiji, and Yasunosuke Chikuni. 1987. Notes on the life history of Sitticus fasciger (Simon, 1880)(Araneida, Salticidae). Journal of Arachnology 205-212. DOI:10.2307/3705730
Aposematic: Away from danger (Ancient Greek). Bright colours to advertise that Graphasoma italicum emits a defensive odour when disturbed. If you have a supply of fresh fennel and lots of seeds you, too, can raise your own colony (8400 eggs per week, with minimal cannibalism or inbreeding![1]) Not enough to make an omelet, but great for breeding parasitic wasps to protect your hazelnut crop.[2]
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
[1] Binazzi, Francesco, et al. "An effective method for Graphosoma lineatum (L.) long-term rearing." Redia 98.1 (2016): 155-160. [2] DOI:10.1080/09670874.2017.1403059
A pair of burnet moths (Zygaena trifolii?* (right) and Z. osterodensis (left)) on a pincushion flower (Scabiosa sp) with some bug eggs between (Graphosoma italicum?). Most moths use odour to find mates, with the female wearing a strong perfume that attracts males from afar. Most butterflies use sight,** with the males flying around until they spot a perching female. Z. trifolii, a day-flying moth, does both. In the mornings, the female will perch up high and wait for the male but in the afternoons she will be deep in the grass emitting pheromones.[doi:10.1017/S0007485316000158]
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
* The genus name Zygaena comes from Ancient Greek for hammerhead shark. The species name trifolii comes from Ancient Greek for clover, which is not the host plant.
** This image shows the visual acuity of longwing butterflies.[doi:10.1098/rsbl.2023.0476] Moths are forced into the olfactory strategy because they fly at night. One wonders how poor it must be if the visual strategy is preferred for diurnal butterflies and moths.
*** Found the following while reading about Zygaena. It’s a caterpillar-eat-caterpillar world out there: Hofmann A and Kia-Hofmann T (2012) Cannibalism of unhatched siblings by larvae of burnet moths (Zygaena Fabricius, 1775), with notes on oophagy and the behaviour of newly hatched larvae (Lepidoptera: Zygaenidae). Entomologist’s Gazette 63:3-36
A day-flying moth (Zygaena loti) with bright colours, so it has a nasty taste. This comes from precursors to hydrogen cyanide (linamarin and lotaustralin) synthesized and collected for self defense. But split them open and you find a tiny ball of sweet nectar; a wonderful treat for the children from northern Italy wandering through the meadows on a hot summer day. The whole moths are somewhat toxic, with an LD50 of 170 moths for a small child, though dizziness and intoxication would set in well before.[DOI:10.2993/0278-0771-29.1.64]
On the right is a green Cryptocephalus leaf beetle, whose larvae are protected by a shell of dung.[wikipedia:Camptosomata] This is initially prepared by their mother, but they extend it as they grow older. “Leave No Trace” taken to the limit.
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
Heliotropism: sun-turning. In this sheltered pollinator café, Leucanthemopsis alpina keeps its tables a balmy 4.5°C above the chilly mountain air. Visitors stay a little longer and collect more pollen before flying to the next hot spot.[DOI:10.1080/15230430.2001.12003409]
2023-07-11 Pointe-d’Emy, Montricher-Albanne, France
Railway beds are hostile environments for plants: strong sunlight, permeable gravel with heavy metals, toxic compounds, and intense use of herbicides. Despite a preference for light shade and rich soils, Geranium robertianum was found in 28% of railways in Poland.[DOI:10.1007/s00606-013-0936-1] This is a combination of acclimatization (e.g., leaves are smaller when growing in full sun) and adaptation (e.g., genes selected for herbicide resistance).[DOI:10.1007/s10646-021-02430-5] It helps that the rail beds are well fertilized by the direct deposit of faecal matter from passenger trains.
2023-07-12 Ruisseau des Moulins, Montricher-Albanne, France
Cantharis tristis, frolicking in the snow on a hot summer day. In one study, 538 800(!) beetles were gathered from central Europe, with 85% identified to species.[DOI:10.1111/1755-0998.12354] About 25000 specimens were sequenced (7 per species) and clustered into a family tree. There were 209 anomalous groupings (6%), either splitting an existing species into multiple groups (as with C. tristis) or merging different species into one group. A monumental effort by a half dozen researchers over five years for a single paper.
2023-07-11 Pointe-d’Emy, Montricher-Albanne, France
The Crois des Têtes peak is composed of Jurassic limestone, dating from 170 million years ago when Micropterigidae (the first moths) appeared.[1] Like much of the Alps, it used to lie at the bottom of the Tethys Ocean before it was thrust and folded by pressure from the African continent.
2023-07-09 Les Karellis, France
[1] http://www.geol-alp.com/h_maurienne/_lieux_maurienne_Nord/Cx_Tetes.html
The common rock-rose (#741) is also popular with our six-legged friends. In this case a pair of plant bugs (Tinicephalus hortulanus) and a pair of moths (Micropterix aruncella). These small-winged moths (Greek: micro+pterix) are in the oldest branch of Lepidoptera (scale-winged), which split from Trichoptera (hair-winged) 180 million years ago. Unlike other moths and butterflies M. aruncella still has a mouth to chew pollen from flowers rather than a proboscis to suck nectar. Fossils from the late Triassic already show the scale structure of modern Micropterigidae making them the oldest known examples of “structural colour” driven by diffraction of light.[DOI:10.1126/sciadv.1700988]
2023-07-09 Les Karellis, France
Adapted for high altitude, Helianthemum nummularium makes its own defenses against UV radiation and temperature stresses. Many of these antioxidants are effective against parasites, which perhaps explains why H. nummularium is overrepresented in the diet of alpine ungulates.[DOI:10.1055/a-1197-2898] Word of the day: zoopharmacognosy meaning “animal drug knowledge”, from Greek zoo + pharmacon + gnosy .
2023-07-10 Les Karellis, France
A mob can stand up to a bully, but only when someone is brave enough to raise the alarm. It’s a question of trust: if nobody shows then this Fringilla coelebs risks being eaten by an owl. Enter some game theory. At the start of the breeding season there is little altruism, and most birds stay quiet. Later, as the fellow migrants get to know each other they will call out when an intruder arrives and join the mob that harries them until they leave.[DOI:10.1098/rspb.2002.2155] A flock of overwintering birds with species such as willow tits (#739) will already display trust. A migrating chaffinch settling in their neighbourhood will sound the alarm even at the start of the season.
2023-07-10 Les Karellis, France
Poecile montanus, like their new world cousins the Carolina chickadee, are excited to find food, calling out to all their friends.[1] Birds not of a feather also flock together, with many species joining the feast. We had a dozen species come through one day, stripping our holly of all its berries.[2] This altruism is both selfish (it is safer to eat with many eyes watching for predators) and efficient (with many birds searching they can find the next tree faster).
2023-07-09 Les Karellis, France
[1] DOI:10.1111/j.1439-0310.2011.01982.x [2] CotD #64 2021-02-04
Thymelicus sylvestris. New word: “despeciation”. Genetically the mitochondria for individuals can be clustered into six groups with nuclear DNA mixing relatively freely between the groups. Perhaps this is evidence of isolated populations evolving into distinct species about 1MYa, then range expansion allowing them to join back to a single species.[DOI:10.1111/mec.15153]
2023-07-09 Les Karellis, France
Aporia crataegi is closely related to the ever-present cabbage white (Pieris rapae) [RBD 89,166]; it also produces a pierisin protein to clear out old tissue during metamorphosis. The discovery was serendipitous if somewhat macabre: presented with an award for cancer research, a flag made from P. rapae and Appias nero, the awardee asked whether butterflies might contain anti-cancer agents.[DOI:10.3390/toxins16060270] The answer was a resounding yes, followed by 30 years of research into how and why.
2023-07-10 Les Karellis, France
Perhaps Knautia arvensis, though maybe one of a dozen closely related species in the Alps alone. It is native to Europe where it is used in traditional medicine to treat itching (scabious comes from latin scabo for scratch). It was brought to North America as an ornamental, but with 2000 seeds per flower it soon escaped. It is designated as a noxious weed in British Columbia and Alberta.
2023-07-10 Les Karellis, France
An overgrown ground squirrel with cold weather adaptations allowing it to thrive on the steppes during the glacial maxima. But the interglacials push them up the mountains leaving isolated populations. The result is extremely low genetic variability, comparable to laboratory mice back-crossed for decades.[1] Despite that, the populations are thriving, including a population in the Pyrenees which has grown from ~400 individuals to ~10000.[2] An early victim of global warming, the Pyrenees population was wiped out when the glaciers retreated 10,000 years ago. Hunters reintroduced them as food for golden eagles, in hopes that the eagles would eat fewer chamois.
2023-07-14 Pointe de Chaudannes, Montricher-Albanne, France
[1] Gossmann, Toni I., et al. "Ice-age climate adaptations trap the alpine marmot in a state of low genetic diversity." Current Biology 29.10 (2019): 1712-1720. DOI:10.1016/j.cub.2019.04.020
[2] López, B. C., Pino, J., & López, A. (2010). Explaining the successful introduction of the alpine marmot in the Pyrenees. Biological Invasions, 12(9), 3205–3217. DOI:10.1007/s10530-010-9712-0
Leucanthemum vulgare complex (les marguerites), but I can’t determine the species. Despite 2 million years of evolution from a common ancestor there are two dozen species that are indistinguishable without a detailed analysis of the leaves.[DOI:10.3390/plants11141878] This one is accompanied by a speckled longhorn beetle (Judolia cerambyciformis; in French lepture trapu).
2023-07-10 Les Karellis, France
Calocoris roseomaculatus, so named for spots on its wings (roseo+maculatus = red + spotted). It is a plant bug (family Miridae) with a particular fondness for the flowers of the oxeye daisy (Leucanthemum vulgare) and the common yarrow seen here (). It’s not too greedy, breeding only one generation per year; it needs a good cold snap before the eggs can hatch in the spring.[1]
2023-07-10 Les Karellis, France
[1] Braune, H.-J. (1971). Der einfluß der temperatur auf eidiapause und entwicklung von Weichwanzen (Heteroptera, Miridae). Oecologia, 8(3), 223–266. doi:10.1007/bf00346473
Papilio machaon on Austrian rocket (Sisymbrium austriacum). Its bright-coloured caterpillars feed primarily on carrot and citrus families, gathering furanocoumarins and converting them into defensive poisons. Some of these are deposited with the frass (caterpillar poop), which can be gathered for use as a natural medicine. Caterpillars reared on ashitaba (a Japanese angelica) produce substances that are highly toxic to HCT116 (a colon cancer cell line).[1]
2023-07-11 Pointe-d’Emy, Montricher-Albanne, France
[1] Nakano, M., Sakamoto, T., Kitano, Y. et al. An extract from the frass of swallowtail butterfly (Papilio machaon) larvae inhibits HCT116 colon cancer cell proliferation but not other cancer cell types. BMC Genomics 24, 735 (2023). https://doi.org/10.1186/s12864-023-09841-0
As an ancient talisman, a simple cross made from goat’s beard (Aruncus dioicus) and great masterwort (Astrantia major) can be blessed by the priest on St. John’s Day (June 24th) and nailed to your chalet, providing protection from lightning, storms and other calamities.[1] This peculiarity from Val de Morgin derives its power from the combination of St John (barbe de St. Jean is the local name for A. dioicus) and Christ (whose blood adds the crimson highlights to A. major), complementary figures in Christianity with birthdays falling on the Roman summer and winter solstice.[2] As a modern talisman, masterwort leaves were found to be highly sensitive to ozone, turning red on the margins. Together with a dozen other sentinel species, this provides a passive network of ozone sensors for Central and Eastern Europe.[3]
2023-07-10 Les Karellis, France
[1] Broadwood, Lucy E. "A Swiss Charm." Folklore 16.4 (1905): 465-467. [2] Saint John’s Eve [Wikipedia] https://en.wikipedia.org/wiki/Saint_John%27s_Eve [3] Manning, W. and Godzik, B. (2004). Bioindicator plants for ambient ozone in Central and Eastern Europe. Environmental Pollution, 130(1), 33–39. DOIi:10.1016/j.envpol.2003.10.033
La Saxifrage paniculée (Saxifraga paniculata) in the golden light of the setting sun. An extremely hardy plant, it can survive summers on hot cliff faces with little water followed by winters with biting winds unimpeded by snow cover. That is, so long as it is left undisturbed. On cliffs where rock climbing is permitted, the saxifrage disappears.[1]
2023-07-13 Pointe des Chaudannes, Montricher-Alabanne, France
* Saxifraga comes from Latin for stone-breaker, for the traditional use of S granulata in treating kidney stones. I can't find studies on its efficacy, but a plant in the same family is used as part of Ayurvedic formulation with 60% success.[2] This is different again from the maidenhead fern, which was called saxifrage by Pliny.[3]
** It is unlikely that all the treatments listed in [3] have undergone double-blind tests. For example, "A wreath of [saxifrage], worn on the head, alleviates head-ache.", or "The leaves, steeped in the urine of a youth who has not arrived at puberty, and beaten up with saltpetre, compose a liniment which, it is said, prevents wrinkles from forming on the abdomen in females."
[1] doi:10.1016/j.jnc.2007.03.002 [2] doi:10.1016/j.eujim.2011.02.003 [3] The Natural History (79 AD). Pliny the Elder. [XXII ch:30] translator: John Bostoc, 1855.
Crépide dorée (Crepis aurea), found exclusively in alpine meadows. Not an aggressive plant, even 135 years after the retreat of the Rotmoosferner glacier in Austria it still has not spread onto the available slopes.[doi:10.1016/j.baae.2005.02.004] Alpine processes are slow, with the earliest plants taking a couple of decades to gain a foothold and begin to build up the soil. After a couple more decades, with a system for water retention and minerals such as phosphorus, legumes can then colonize, bringing with them their nitrogen-fixing root microbes. Decades later, late-succession plants can then compete in a stable, nurturing environment.
2023-07-11 Pointe d'Emy, Montricher-Albanne, France
Small cattle herds added to the soundscape of our morning walks, such as these tartenaise(?). Specialized for altitude, even on the highest ridges you still have to watch for cow pads. The rich variety of forage in alpine meadows contributes to the distinctive bouquet of cheeses such as Abondance (Appellation d'origine contrôlée, Haute-Savoie, France). In an example of hyperlocal specificity, this study [doi:10.1017/s0022029999003842] found that cheese made from cows grazing on the north slope at 1500 m had distinct flavour and texture from cheese made from the same herd grazing on the south slope at the same altitude. The bacterial and chemical composition of the milk changed with the pasture composition as the cows went back and forth, giving more "burnt, sour" from the north compared with "toffee, exotic fruit" from the south.
2023-07-11 Les Karellis, Montricher-Albanne, France