November 26, 2013 by Chris Buddle

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!)

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)

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

October 3, 2013 by Chris Buddle

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)

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)

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.

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.

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.

“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)

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.

August 19, 2013 by Chris Buddle

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)

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.

Next, another awesome fly, from Rachel Graham:

Warren Sarle submitting this photo – lovely little jumping spiders!

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!

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.

July 26, 2013 by Chris Buddle

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.

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?

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.

July 11, 2013 by Chris Buddle

Help give this jumping spider a common name

There’s a small brown/grey mottled jumping spider that is very common on the exterior walls of my house. It’s curious, cute, always on the move. A few years ago I identified the species as Sitticus fasciger, a jumping spider known from many parts of Asia, and since the 1950s, from North America. It is now found in Quebec, Ontario, most likely other parts of eastern Canada, Manitoba, and many parts of the USA, west to Missouri. This species is synanthropic – meaning it lives in close association with humans. More specifically, it’s found most commonly on houses and buildings (at least in the Nearctic).

Sitticus fasciger, photo by Thomas Shahan, reproduced here with permission (see more of his work here!)

That photo by Thomas Shahan is really stunning, but I must admit that most individuals I have seen are more brown/grey, and less ‘vibrant’ that the photo above. Have a peek at this video of a female (taken at my house) for what I think is more typical coloration:

Little is known about the biology of this lovely little spider – some work by Matsumoto and Chikuni (1987), done in Japan, discusses its life history, and a few nice websites have videos and other summaries of diagnostic characteristics and summaries of its distribution. (here, by the way, is the original description by Simon). I’m not certain about the etymology of fasciger. In latin, it refers to a ‘bundle of sticks or rods‘, which is not that informative. As Morgan Jackson points out, in middle Irish it could mean ‘neckband‘ which might refer to some of the coloration on the cephalothorax or abdomen.

This species, however, is lacking a common name, and I seek your help in determining one!

Although there are a lot of opinions about using common names for insects/spiders, I am generally in support of this idea. I think a more general audience likes to use common names, and I think common names can provide a nice context and description that is often missed with a latin name. The Zebra spider (Salticus scenicus), for example, is a well known cosmopolitan species, and that common names says something about how the spider looks to most people. Similarly, the Dock (or Wharf) spider is a nice common name for Dolomedes tenebrous since a wharf is a very common habitat! I think it’s a pretty ambitious task to give all species a common name, but I do think more common species should be given a common name.

So, with that introduction, let’s pick a common name for Sitticus fasciger. I asked for suggestions on twitter, and discussed this topic with a few people. I have set up a poll, below, with some of these suggestions. I’ll leave the poll open for a couple of weeks (until 25 July), and then share the results with you. I will then work to get this name formally accepted by both the Entomological Society of Canada and the Entomological Society of America.

–POLL CLOSED–

September 12, 2012 by Chris Buddle

Arthropods in the tree-tops: Canopy ecology in Quebec (Part 2)

Part 1 of this series highlighted how our laboratory accesses the forest canopy. This post is about our projects related to understanding patterns of Arthropod diversity in Quebec’s forest canopies.

I will first highlight some work done by my former PhD student Dr. Maxim Larrivée. Max started in my lab at the exact time that I received the grant for the mobile lift platform, and he become an expert at this machine, and he proved to be an immensely talented student. His project was focused on understanding the spatial patterns of spider diversity in three deciduous forest sites located within an hour drive of the Island of Montreal. In the first part of his dissertation, Max collected almost 14,000 spiders representing 82 species (Larrivée & Buddle 2009). The spider fauna of the canopy was markedly different from the fauna from the understorey, and it is likely that different mechanisms structure the assemblages in the two habitats.

Overall fewer spiders and fewer spider species were found in the canopy compared to the understorey, but at a species-specific level, there were some spiders that seemed to have a preference for living in tree-tops. For example, the lovely jumping spider (Salticidae) Hentzia mitrata was significantly more common in the canopy. We were also most excited to document the species Mastophora hutchinsoni (Araneidae) in the canopy – this is the famous “bolas spider” and we believe our canopy record may be the most northern record for the species. The Bolas spider hunts by swinging a strand of silk at its prey, and this strand has a “bolas” of sticky capture thread at the end. This species is truly fascinating, and in our system, it is a species that likes the canopy.

Max demonstrating the methods of using a beat-sheet to collect spiders in the forest canopy. Here, he is about 25 m above the forest floor.

The follow-up work to this baseline study was focused on understanding dispersal potential of spiders in the canopy as compared to the dispersal potential of understorey species. Most spiders in our system are small, so we predicated that their main mode of dispersal was via ballooning (i.e., releasing a small strand of silk and letting the wind carry the spider away). We had also hypothesized that dispersal might be one of the mechanisms behind the aforementioned patterns community structure in the canopy compared to the understorey. Max collected live spiders in the canopy and understorey and set them up in a wind-tunnel in the laboratory. He then documented each species’ propensity to disperse by looking at the frequency by which they showed ‘tip-toe’ behaviour (a pre-ballooning condition). In the paper resulting from this research, we reported that the spiders in our system do have high dispersal potential, but that this potential did not differ depending on whether the spider was collected in the canopy as compared to the understorey (Larrivee & Buddle 2011). This was a fascinating area of study, and we are left with as many questions as we started with! For example, if dispersal potential doesn’t differ between canopy and understorey species, what mechanism drives the differences in community structure between the two habitats?

Our laboratory has been studying beetles as well as spiders – although I am personally very interested in spiders, I do recognize the beauty of beetles, and their important ecological roles in virtually all ecosystems. One of Max’s field assistants (Brianna Schroeder) was keen to complete a small project about beetles so she set Lindgren funnels in the canopy and in the understorey. Over 170 species were collected, and once again, the fauna from the canopy was differentiated from that of the understorey (Schroeder et al. 2009).

Max up in the canopy crane!

Two other field assistants that worked with Max (Kristen Brochu and Katleen Robert) also worked on their own projects, and together with my colleague at McGill University (Prof. Terry Wheeler), we are close to finishing up a manuscript to describe more patterns of arthropod diversity as a function of vertical stratification in Quebec’s deciduous forests – this work includes beetles as well as flies (Diptera). Although the responses are not the same for the different groups of insects, we are finding that both beetles and flies show vertical stratification in our study sites.

Stay tuned for Part 3, which will focus on ecological interactions occurring in the Canopy.

July 17, 2012 by Chris Buddle

A classy canopy-dwelling jumping spider: Hentzia mitrata

I have just returned from a week of field work in the Yukon – and will report on that in some detail soon. However, in the interim here is a short story about a lovely jumping spider (Family Salticidae). This is a story that started quite a few years ago, with my graduate student at the time, Maxim Larrivée. Max documented that the spider fauna of canopies of the forests around Montreal hosted fewer spiders than the understorey, and a lower number of species than the understorey (Larrivée & Buddle 2009). However, he also noticed and documented that there were a handful of specific spider species that were more frequently encountered in the canopy compared to the understorey, including a stunning jumping spider Hentzia mitrata. Here’s a photo, courtesy of Thomas Shahan . (you can view more of Thomas’ amazing photographs here):

Hentzia mitrata, copyright T. Shahan, reproduced here with permission

Just recently our laboratory had a publication come out in The Canadian Entomologist on another study of spiders (and beetles) in the canopy of forests at the Morgan Arboretum (Aikens & Buddle 2012). This was work done by my former MSc student Kathleen Aikens. As one part of her work, Kathleen asked whether there was vertical stratification in beetle and spider assemblages – there was, and in addition to that finding, Kathleen again documented that Hentzia mitrata was more common in the canopy as compared to the understorey – here’s a figure from that paper showing those data:

We have now published this finding three times – in Max’s work on foliage dwelling spiders (Larrivée & Buddle 2009), his work on bark-dwelling canopy spiders (Larrivée & Buddle 2010), and now with Kathleen’s work. This is a convincing body of evidence: Hentzia mitrata has a strong affinity for tree canopies.

But why? Why is this species more common in the canopy compared to the understorey? What does it eat in the tree-tops? Where does it overwinter? (our deciduous forest are bare, cold and snowy in the winter!). As is typical, I have no idea. We have yet to embark on any life-history study of Hentzia mitrata in the canopy, but it would be well worth pursuing. In my experience, this species is not all that common in understorey habitats at our latitude, yet there it is, watching us with its big, curious eyes as we enter its tree-top realm:

Hentzia mitrata, copyright T. Shahan, reproduced here with permission

References

Aikens, K.R. & C.M. Buddle. 2012. Small-scale heterogeneity in temperate forest canopy arthropods: stratification of spider and beetle assemblages. The Canadian Entomologist, in press. doi:10.4039/tce.2012.51

Larrivée, M. & C.M. Buddle. 2009. Diversity of canopy and understorey spiders in north-temperate hardwood forests. Agricultural and Forest Entomology 11: 225–237 DOI: 10.1111/j.1461-9563.2008.00421.x

Larrivée, M. & C.M. Buddle. 2010. Scale dependence of tree trunk spider diversity patterns in vertical and horizontal space. Ecoscience 17:400-410 DOI 10.2980/17-4-3403

Arthropod Ecology

Writings about arthropod ecology, arachnids & academia at McGill University

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