Spiderday (#22)

It’s been a couple of weeks, but nevertheless, here is another edition of SPIDERDAY! All the best Arachnid-themed links, pulled from the web in the last little while.

Just look at this Jumping spider keeping an eye on her babies! Photo by Nick Porch (reproduced here with permission)

Just look at this Jumping spider keeping an eye on her babies! Photo by Nick Porch (reproduced here with permission)

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Spiderday (#16)

You latest edition of SPIDERDAY!  (sorry, folks, it’s been a busy week, so I just don’t have as many links as usual)

An amazing photo of a Solifuges (aka Camel Spider), by Sean McCann

An amazing photo of a Solifuges (aka Camel Spider), by Sean McCann

SpiderPortrait

Spiderday (#11)

Here are your latest Arachnid-links… SPIDERDAY is here!

Some great jumping spider photos from Daniel, taken with a magnifying glass and a phone. Impressive!

Lyssomanes species, from Daniel Llavaneras, reproduced here with permission.

Lyssomanes species, from Daniel Llavaneras, reproduced here with permission.

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Spiderday (the second)

Welcome to the second edition of Spiderday! (here’s the first one): a weekly round-up of neat stories about Arachnids.

First up, an amazing shot of fishing spider, from Nash Turley!

A Pisauridae spider, photo by Nash Turley (reproduced here with permission)

A Pisauridae spider, photo by Nash Turley (reproduced here with permission)

Here are some links I stumbled across this week:

KnowledgeGraph_Spiders

Under the influence: how insecticides affect jumping spider personalities (Part 2)

This post is written by former PhD student Raphaël Royauté, and is a plain-language summary for our most recent article titled: Under the influence: sublethal exposure to an insecticide affects personality expression in a jumping spider

It’s well known that personalities can shift and change when we are ‘under the influence’ of chemicals, be it drugs or alcohol. As entomologists, we also consider this question for the insects and spiders that live among us: although we assume arthropods can similarly be affected by chemicals in their environment, it’s less clear how these chemicals may affect the personalities of these arthropods. We tested the effects of insecticide residues on the personalities of a jumping spider known to live in apple orchards. We found that individual-based personality shifts occurred when spiders were exposed to sub-lethal doses of an insecticide. This mean that even before we might see ‘population-level’ effects of insecticides on an important predator in agro-ecosystems, individual spiders themselves get, um, sort of messed up when under the influence.

How is this cute jumping sipder affected by insecticides? (photo by C. Ernst, reproduced here with permission)

How is this cute jumping sipder affected by insecticides? (photo by C. Ernst, reproduced here with permission)

Insecticides are often used in agriculture for various reasons, but can have negative effects on the ‘non-target’ fauna living in our agricultural fields. One of the most important challenges in evaluating their toxicity is that these chemicals can persist at low concentration in the environment. These concentrations are unlikely to kill exposed organisms but may substantially alter behaviours. Most of our evidence of the toxicity of insecticides on behaviours comes from studies on pollinators and research has shown decreases in spatial memory and learning capacities.

There remain gaps in our knowledge about how other types of organisms respond to these compounds. Studies on insecticide toxicity may be also limited because they tend to ignore how insecticides shape variation in behaviour. This is important because individuals differ in their behavioural tendencies and may not have the same weight in ecological processes: some individuals are more active, show more aggressiveness or consume more food. Personality traits can also be inter-related and form “behavioural syndromes”: clusters of behavioural traits that are correlated and evolve as a package. If personality traits are interconnected, any insecticide modifying one trait is likely to alter the whole syndrome. We’ve shown previously that behavioural syndromes differed between populations exposed and unexposed to insecticides in the Bronze Jumping Spider, a species common in apple orchards and known to prey on several economically important pests. But those populations could be different for a variety of reasons: for example, perhaps the insecticides affect spider behaviours because there is simply less food available in insecticide-exposed areas for example.

We wanted to test if insecticides could be directly responsible for the shifts in personality and behavioural syndromes we noticed. In other words, when a spider is “under the influence” of insecticides, is it still behaving according to its personality type?

The similarities between insecticides and drugs is fascinating: Both types of compounds target the nervous system, both can affect behaviours and both can kill above a certain lethal dose. In fact caffeine and nicotine evolved as natural plant defenses against insect herbivory and the latter was one of the first insecticides ever used. As crazy as it sounds, the effect of psychoactive drugs has been investigated in spiders in the past! The legend goes that, back in 1948, zoologist H. M. Peters was annoyed by his garden spiders spinning webs at “such ungodly hours” (2 am-5am). He wanted to found a compound that would shift the spinning behaviour to more a “decent” schedule, and he asked pharmacologist Peter N. Witt for help. Witt tried different psychoactive compounds on the spiders, including caffeine, LSD and marijuana but couldn’t produce the desired effect. What he found was in fact much more interesting: each compounds produced a distinct type of “drug web”, altering its shape, size or regularity ! (from Foelix’s “Biology of Spiders”) More recent research has shown that some commonly used insecticides affect web building in the same way drugs do.

We focused on how activity and prey capture capacities were affected by exposure to a widely used insecticide (phosmet) in the Bronze Jumping Spider. We tested activity and prey capture before and after exposure the insecticide and compared the amount of behavioural variation with that of a control group. Doing research in ecology sometimes requires using original equipment. In our case we found that the best way to expose our spiders to the insecticide was to use a hotdog warmer! We applied the insecticide solution on test tubes and used the rotation of the hotdog machine to get a homogeneous surface coated with dry insecticide residues. This allowed us to have a more precise control of the dose that each spider received while simulating field exposure conditions.

Unusual research equipment: hot-dog warmer.

Unusual research equipment: hot-dog warmer. (photo by R. Royaute)

One of our study spiders, in its tube. (Photo by R. Royaute)

One of our study spiders, in its tube. (Photo by R. Royaute)

We did not found any effect of the insecticide on average behaviour between treatments but the ranking of individuals was strongly affected after insecticide exposure. In general spiders exposed to the insecticide were more variable in their behavioural tendencies. This suggests that the effects of insecticides on personality differences may manifest before any effects on the population as a whole are detected, in which case scientists may be frequently underestimating the toxicity of insecticides. Another puzzling result was that males and females did not respond in the same way to insecticide exposure. Males were most affected in the way they explored their environment but their capacity to capture prey remained intact. Females instead showed a decrease in the strength of the activity-prey capture syndrome.

Spiders play an important role in agricultural fields as they help regulate pest outbreaks. By altering personality differences and their syndromes, insecticides may limit spiders’ capacity to provide this important ecosystem service in subtle ways. As usual, this research leads to more questions than answers. At the organism’s level, it is important to understand how long these personality shifts last for. Do these shifts vary depending on how frequently spiders get exposed to insecticide or to what types of insecticides they are exposed to? How do they ultimately affect a spider’s capacity to escape predators, capture prey or reproduce depending on the individual’s personality? At the ecosystem level, prey get exposed to insecticides too, what happens to the predator-prey dynamics when the personality of both prey and predator is affected? How does that translate into biocontrol services? These are all important questions that I hope to contribute to in the future. Stay tuned!

A male bronze jumper (Eris militaris). Photo by C. Ernst, reproduced here with permission.

A male bronze jumper (Eris militaris). Photo by C. Ernst, reproduced here with permission.

References:

Royauté, R., CM Buddle & C. Vincent: Under the influence: sublethal exposure to an insecticide affects personality expression in a jumping spider. Functional Ecology. . http://dx.doi.org/10.1111/1365-2435.12413

Godfray, H.C.J., T. Blacquiere, L.M. Field, R.S.Hails, G. Petrokofsky, S.G. Potts, N.E. Raine, A.J. Vanbergen & A.R. McLean. 2014. A restatement of the natural science evidence base concerning neonicotinoid insecticides and insect pollinators. Proc. R. Soc. B 281: 40558 http://dx.doi.org/10.1098/rspb.2014.0558

Royaute, R., C.M. Buddle & C. Vincent. 2014. Interpopulation Variations in Behavioral Syndromes of a Jumping Spider from Insecticide-Treated and Insecticide-Free Orchards. Ethology. 120, 127-139. http://dx.doi.org/10.1111/eth.12185

Nathanson, J.A. 1984. Caffeine and related methylxanthines: possible naturally occurring pesticides. Science. 226, 184-187. http://dx.doi.org/10.1126/science.6207592

Rainer F. Foelix (2010). Biology of spiders. Oxford University Press. p. 179.

Samu & Vollrath. 1992. Spider orb web as bioassay for pesticide side effects. Entomologia Experimentalis et Applicata. 62, 117-124. http://dx.doi.org/10.1111/j.1570-7458.1992.tb00650.x

Congratulations to the new Doctor of spider behaviour

I’m delighted to announce that lab member Raphaël Royauté successfully defended his PhD yesterday….  and he did it with grace, maturity, and poise. The defence was fair, but tough, and Raphael was able to show his breadth and depth of expertise on the broad topic of behaviour in arthropods.

Raphaël’s thesis was titled “Factors influencing behavioural variation in apple orchard populations of the jumping spider Eris militaris (Araneae: Salticidae)” and the during the defence, he was asked (not by me, remarkably!) to offer a ‘tweet’ of the his thesis. Here it is, coming in at almost exactly 140 characters.

Raph's thesis, in a tweet.

Raph’s thesis, in a tweet.

So, his research looked at behavioural syndromes in this remarkable jumping spider: Raphaël collected spiders in apple orchards, maintained them in a laboratory and ran them through a battery of behavioural test. He defined behaviours, looked at correlations among these behaviours (sometimes called ‘personality’), and how these traits varied during the development of individuals, consistency of these behaviours and whether behaviours differed depending on whether the spiders came from insecticide-free on insecticide-treated orchards.  Raphaël also looked at the direct effect of sub-lethel effects of insecticides on behaviour and will soon be publishing the ways that insecticides mess up their personalities.

Raphaël has really done incredible work – but looking back, I should not be surprised. Soon after he arrived in the lab we worked together on a short project about the activity of spiders right after snowmelt, at at that point, I was impressed with his intellectual curiosity, drive and motivation, and overall approach to scientific research.

Raphael and me, in 2008

Working together on Raph’s first project at McGill

After that first project, Raphaël came back to McGill to work on a PhD with me and Dr. Charles Vincent as co-supervisors. And now, many years later, he is now successfully defended a PhD. What a marvellous journey, and I can honestly say that I’ve learned far more from Raphaël than he could have learned from me.

Good luck Raph! (And you’ll be missed in the lab)

Charles Vincent (l), Raphaël (c) and me (r), just after the Defence (17 March 2014)

Charles Vincent (l), Raphaël (c) and me (r), just after the Defence (17 March 2014)

The effect of insecticides on jumping spider personalities

This post was written by C. Buddle and R. Royaute (a PhD student in the Arthropod Ecology lab).

We are pleased to announce a recent publication from our lab, titled Interpopulation variations in behavioral syndromes of a jumping spider from insecticide-treated and insecticide-free Orchards.  As is traditional in the lab, here’s a plain language summary of the work:

Agriculture has strongly intensified in the last 60 years, causing major concerns the sustainability of biodiversity. Agricultural practices can reduce habitats available for wildlife and also release toxins in the environment through the use of pesticides. Not all organisms living in agricultural fields are harmful, and many predators, including spiders, can help to reduce pest density. We have a relatively good knowledge that the diversity of spider species in agriculture, especially under our temperate latitudes, can help reduce pest damage. However, many of the factors that influence spider predation on pests depend on the outcome of behavioural interactions and we don’t know much about that topic. Spiders are often cannibalistic and aggressive with one another and these types of behaviours may limit their efficiency for pest control. We also need to understand if these aggressive tendencies vary depending on the type of agricultural field considered, a pesticide treated field may favour very different behaviours than one that is managed organically. Another important point is that populations are composed by a multitude of individuals, each with its own behavioural tendencies. Some individuals take more risks when confronted with predators (i.e. they are more bold), others are more active and explore larger areas or consume more prey. These tendencies – often referred to as personality traits – may also be correlated with one another.

In the context of agriculture, this may mean that certain individual spiders may contribute more to biocontrol because they consume more prey, or that certain individuals are more at risk of being in contact with pesticides because they are more active. To understand, how agricultural practices, and particularly insecticidal applications, affects personality and behavioural syndromes in spiders, we focused on the jumping spider Eris militaris, an abundant and charming jumping spider occurring in apple orchards in Quebec. Here’s a lovely photo from Crystal Ernst to illustrate how attractive they are: (thanks, Crystal, for permission to post the photo here!)

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We collected spiders from pesticide-treated and pesticide-free orchards, brought them back to the laboratory, and did a number of behavioural tests on the individuals from the two populations. Compared to the insecticide-free populations, we document that individuals from orchards that did receive insecticides experienced a shift in their behaviours syndromes. The overall shape of this syndrome is multidimensional, but it suffices to say that the correlations among different behaviours (the ‘syndromes’, otherwise known as the ‘personality’) differed depending on where the population came from.

A 'mirror test' - used to study behaviour in E. militaris (photo by R. Royaute)

A ‘mirror test’ – used to study behaviour in E. militaris (photo by R. Royaute)

In sum, the personality shifts that we documented for E. militaris are potentially quite important since the relationships between different behaviours may affect a spider’s ability to be an effective generalist predator in apple orchards. We need to consider how management  (including use of insecticides) may affect specific behaviours, and more importantly, the relationships between the different behaviours.

Reference

Royaute, R., C.M. Buddle & C. Vincent. 2013.  Interpopulation Variations in Behavioral Syndromes of a Jumping Spider from Insecticide-Treated and Insecticide-Free Orchards. Ethology. doi: 10.1111/eth.12185

My favourite spider species: a natural history story 120 years in the making

A little while ago my nephew asked me what my favourite spider was. I quickly answered “Peckhamia picata“, in part because I had recently returned from a field trip in which that species was collected (a trip to one of my favourite places in Quebec), but also because the species has the most amazing habitus: is a myrmecomorph – a species that looks a heck of a lot like an ant. Here’s a photo to illustrate this:

A species of jumping spider in the genus Peckhamia (photo by Alex Wild, reproduced here with permission)

A species of jumping spider in the genus Peckhamia (photo by Alex Wild, reproduced here with permission)

So, what does this species do? What are its behaviours? Where does it live?

I started digging around to see what literature exist on this species. There are certainly many publications that discuss its distribution – it is on many checklists (see here for a relatively complete list), and I was aware that it was originally described as Synemosyna picata (by Hentz, in 1846).

I did a search of Web of Science for publications with the species name, and came up with two hits. One was a systematics papers on a related genus of jumping spider, and the second was a paper by Durkee et al. in 2011*.  They did some laboratory studies of the species, to assess whether or not its ant-like appearance helped it avoid being eaten by predators (spoiler: the answer is yes). A little more digging on-line took me to various sites, and in some cases, I came across this statement:  “almost no information on them

What?  Really?

A Peckhamia picata, from Quebec (Photo by J. Brodeur, reproduced here with permission)

A Peckhamia picata, from Quebec (Photo by J. Brodeur, reproduced here with permission)

Peckhamia picata is a widespread species, with an incredible appearance, and it’s a jumping spider!  Salticids are the darling of the arthropod world –> the panda bears of the invertebrates: big eyes, furry, fascinating courtship behaviours, and truckloads of ‘personality’.  Surely we know SOMETHING about what I declared as my favourite species.

Thankfully, in a filing cabinet in my laboratory, I have a series of older publications on the Salticidae, including “A Revision of the Attidae of North America” by Peckham & Peckham (1909) [available here as a PDF download – note: big file!]. The George and Elizabeth Peckham did an incredible amount of work on the Salticidae (called Attidae, previously). The Peckhams are themselves a fascinating story – some details are on their Wikipedia page  and I’ll summarize briefly: they were teachers (in Wisconsin), natural historians, behavioural ecologists and taxonomists, notably with jumping spiders.  The bulk of their work was done in the late 1800s, and they often cited and discussed Darwinian concepts. They were awesome and I would have liked to meet them.

Another stunning Peckhamia species, this one from Thomas Shahan.

Another stunning Peckhamia species, this one from Thomas Shahan.

So, back to Peckamia picata: Their 1909 tome states the following about the species “We have described in detail its mating and general habits in Vol. II, Part 1 of the Occ. Pap. Nat. Hist. Soc. Wis. pp. 4-7)”.

So, apparently 1909 does not take us far enough back in history to learn about Peckhamia picata. Their paper from 1892 had all the details, and thankfully was fully accessible on the biodiversity heritage library.

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Here is some of the lovely writings about Peckhamia picata, from the Peckhams, in 1892 (transcribed from their papers):

About appearance:

While picata is ant-like in form and colour, by far the most deceptive thing about it is the way it which it moves. It does not jump like the other Attidae [Salticidae], nor does it walk in a straight line, but zig-zags continually from side to side, exactly like an ant which is out in search of booty. This is another illustration of which Wallace has shown in relation to butterflies ...”

(note: The Peckhams give a node to that Wallace guy….)

About feeding behaviour:

Spiders commonly remain nearly motionless while they are eating; picata, on the other hand, acts liks an ant which is engaged in pulling some treasure-trove into pieces convenient for carrying I have noticed a female picata which, after getting possession of a gnat, kept beating it with her front legs as she ate, pulling it about in different directions, and all the time twitching her ant-like abdomen

Regarding courtship:

From the Peckham's 1892 publication.

From the Peckham’s 1892 publication.

His abdomen is lifted vertically so that it is at right angle to the plane of the cephalothorax. in this position he sways from side to side. After a moment he drops the abdomen, runs a few steps nearer the female, then then tips his body and begins to sway again. Now he runs in one direction, now in another, pausing every few moments to rock from side to side and to bend his brilliant legs so that she may look full at them.”

In sum, this journey of discovery has made me fall in love with Peckhamia picata even more. It’s also reminded me that OLD literature is essential to our current understanding of the species we identify. There is a wealth of information in these “natural history” papers – although the writing is in a different style, it is scientific, it is the foundation of current biodiversity science.  We cannot ignore these older books and “Occasional papers”. We can’t rely on quick internet searches and we certainly can’t rely on literature indexed on Web of Science.

We must dig deep and far into the past. There are ‘treasure-troves’ aplenty.

—————–

*The oldest paper cited in Durkee et al. is from 1960. They did not cite the Peckhams.

Another Peckhamia species, courtesy of Matt Bertone (reproduced here, with permission)

Another Peckhamia species, courtesy of Matt Bertone (reproduced here, with permission)

References:

Durkee, C. A. et al. 2011. Ant Mimicry Lessens Predation on a North American Jumping Spider by Larger Salticid Spiders. Environmental Entomology 40(5): 1223-1231

Peckham, G.W., and E.G. Peckham. 1892. Ant like spiders of the family Attidae Occ. Pap. Nat. Hist. Soc. Wis. II, 1 .

Peckham, G.W., and E.G. Peckham. 1909. Revision of the Attidae of North America. Trans. Wis. Academy of Sci., Arts & Letters. Vol. XVI, 1(5), 355-646.

Expiscor (19 August 2013) – The Photography Edition (Part 2)

Last week was Part 1 of the Photography editions of Expiscor (this is because I was been doing remote field work and have thus been unable to keep up on science links, and now I’m on vacation!).  Here’s Part 2 – and again, I thank the Photographers for letting me post their work here, and for directing me to their favourite nature image.

First up, a lovely shot from Morgan Jackson, a Micropezidae fly (genus Raineria)

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An Expiscor favourite Adrian Thysse submitted this photo, with the following comment: My ‘favourites’ change every week, but here is a shot that was one of themost popular images at the Bug Jamboree at the Ellis Bird Farm last Saturday. It is a meadowhawk, Sympetrum sp. , taken with very shallow depth of field to smooth-out the background and to accentuate those magnificent eyes.

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Next, another awesome fly, from Rachel Graham:

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Warren Sarle submitting this photo – lovely little jumping spiders!

Salticidae

The next photo comes with a story, here’s what Matt Bertone writes about this image:

I was walking on a trail near our local lake (Raleigh, NC, USA), when I came upon a harvestman. I didn’t think much of it until I saw this tiny ceratopogonid sucking hemolymph out of its leg. I had been wanting to find this phenomenon, so I took a couple photos (others show the whole scene) and then was on my way to find new subjects. After posting on facebook and having Chris Borkent comment on it, I sent the photo to Art Borkent, a world expert on punkies. He was amazed at what I had found – Opiliones as a host was only recorded once ever, and only in Brazil. I was kicking myself for not getting the specimen, but at least the shot turned out well!

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Ok, time to move away from the “All Arthropod” show… here’s an image of my own and here’s the story: Last week I was in Cambridge Bay, Nunavut, doing field work. While doing a “tundra walk” one afternoon, we stumbled across a tiny patch of Asters, tucked in among some rocks. It was a beautiful moment because it was very late season, and we observed very few flowers. However, these stunning Asters took my breath away. Delicate, beautiful, fragile.

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The Mottled Jumper: a new common name for a jumping spider

A couple of weeks ago I set up a poll so that you could help give a jumping spider a common name.  This was all made possible thanks to a series of fun twitter conversations which ultimately led to the list of potential common names for Sitticus fasciger.

Sitticus fasciger, photo by Thomas Shahan, reproduced here with permission.

Sitticus fasciger, photo by Thomas Shahan, reproduced here with permission.

Crowdsourcing a common name received a bit of press (e.g., CBC Homerun, the afternoon radio show in Montreal), and this led to discussions about the process of giving species a common name.  For the record, with about 20,000 described arthropods in Canada, fewer than 1700 have common names (you can refer to the Entomological Society of Canada’s list of common names). There’s a lot of work to do!  There is a committee within the Entomological Society of Canada, and anyone can submit a common name – there is even a fillable form!  However, the common name must make sense, and have some meaning that relates to the species biology, appearance, or life history. A group of experts will evaluate the proposal, and if accepted, a species can receive a common name.  So, after this project with Sitticus fasciger, my work is not done: I will now proceed to get the selected common name officially accepted, and will eventually submit it for approval to the Entomological Society of America, also.

OK, enough of this… what about the poll results?

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Sitticus fasciger: over a hundred people have spoken… and the common name selected is the Mottled Jumper. That name received over 45% of the vote. It is also my personal favourite – mottled refers to irregular arrangement of patches of colour, and is an accurate description of the spider.

In sum, THANKS everyone for taking part – it was a fun project, and hopefully there will be more to come in the future.