Spiderday (#10)

Spiderday is back! I was away for a little while, but am happy to bring you some arachnid stories pulled from the web over the last little while.

But first, do check out photos from Colin Hutton:

A tailless whip scorpion, by Colin Hutton (reproduced here with permission)

A tailless whip scorpion, by Colin Hutton (reproduced here with permission)

Pseudo

 

Yukon field work: Arachnids, landscapes, and the inspiring North

It’s a dream for an arthropod ecologist: a dramatic biome transition from boreal forest to subarctic tundra, a beringian landscape, and diverse and abundant insects and spiders. I have just returned from field work along the Yukon’s Dempster Highway, Canada’s only road to cross the Arctic circle. And again, I was not disappointed!

A stretch of the Dempster Highway

A stretch of the Dempster Highway

This year’s expedition was focused on three projects:

1) Tiny, wonderful arachnids:

On this trip, I continued to document the distribution of an arctic Pseudoscorpion, Wyochernes asiaticus. This is a beringian arachnid, known from the old world, and known in North America from almost exclusively unglaciated parts of the Yukon and Alaska. Like wooly mammoths and giant short-faced bears, these tiny arachnids roamed North America while the rest of the top half of the continent was buried under ice. But unlike the mammoths and giant short-faced bears, the Arctic Pseudoscorpion is not extinct! It’s a relict of the past, thriving today under rocks near beringian rivers and streams. I have been working on this species for many years (and a life history paper about this arachnid will appear in the Canadian Field-Naturalist sometime this month), and each time I visit the Yukon, I leave with more questions, and more specimens. This time, I collected some animals to hopefully work on their population genetics: I am curious about the relatedness among the populations from different watersheds along the Dempster Highway (by the way, I am seeking collaborators [phylogeographers!] for this work… If interested, let me know!)

The Arctic pseudoscorpion, Wyochernes asiaticus

The Arctic pseudoscorpion, Wyochernes asiaticus

2) Northern food webs:

I have left my PhD student Shaun Turney up in the Yukon (along with his field assistant) where he is working on characterizing the arthropod-based food webs along the latitudinal gradient of the Dempster Highway. Past research has given some hints that northern food webs may be atypical, but to fully test this we decided to characterize the entire fauna from 1 x 1 m patches of the tundra. This involved placing tents over the tundra, and Shaun collected critters within those tents, and even “vacuumed” the tundra within the square metre. Shaun started this work near the stunning Richardson mountains above the arctic circle, and over the month of July, will repeat the sampling at different locations along the Dempster Highway.

Shaun Turney, vacuuming the Tundra.

Shaun Turney, vacuuming the Tundra.

3) Thermal biology of wolf spiders

Colleagues from Western University joined me in the Yukon to start some projects related to the thermal biology of the extremely abundant Pardosa wolf spiders which inhabit the tundra. There are several species that occur along the Dempster Highway, and when the weather is good, it’s quite possible to collect hundreds of individuals over the span of several hours. Past work has suggested the density of these spiders is about 0.5 per square metre, and those past estimates certainly seemed accurate on this trip also! The spiders will be taken back to their lab, and I am eager to find out how northern Pardosa may be adapted to Yukon conditions.

Searching for wolf spiders on the Tundra

Searching for wolf spiders on the Tundra

All the sciency parts of our field work were exciting and gratifying, but there are other reasons why the Yukon is special*: it is a breathtakingly beautiful place. From stubby black spruce trees to tufts of tundra-dwelling cotton grass, every turn of the highway or footstep over a hummock is a treat. It’s not all easy (hordes of mosquitoes at some of the campgrounds, or being driven off the tundra by cold rains and strong winds), but it is all inspiring.

The lines between science and passion are blurred on the tundra, and that is a good thing. Searching for spiders is work that is fun; seeing a northern shrike or watching two lonely caribou dart up a river valley is fun that comes with the field work. I am immensely grateful for being able to hike under midnight sun, and be a northern researcher during the day. I am delighted to be able to discover some of hidden secrets of the Yukon.

The northern landscape, near the Yukon-Northwest Territory border.

The northern landscape, near the Yukon-Northwest Territory border.

For more photos of the recent trip, check out my Flickr page.

——

* my colleague Terry Wheeler shares a passion for the Yukon – here is his post which outlines why he keeps returning to the region.

Spiderday (the ninth)

Here’s your ninth edition of SPIDERDAY! Some arachnid-related links from the past week.

Please note: I’m just heaving off to the Yukon for a couple of weeks of remote field work (it will involve arachnids!). Spiderday will likely return on 18 July.

Wow - this is a Thomisidae (crab spider) that's an ant-mimic. In Australia, of course. Photo by Alex Wild.

Wow – this is a Thomisidae (crab spider) that’s an ant-mimic. In Australia, of course. Photo by Alex Wild.

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  • Scorpions, anyone? How about GIANT ones. An amazing post with stunning images that you just won’t believe!
  • Some very handsome Opiliones (Harvestmen, or daddy-longlegs)
  • This is from a while ago, but worth another read. The fastest land animal (scaled to relative body size) is… a MITE!
  • Tips for tick safety. Worth a look.
  • Here’s a great technique that arachnophiles are sure to use!

Spiderday (the eighth)

Hip Hip Hooray! It’s Spiderday! I’ve snared some of the best arachnidy links from this past week. But first… a big hug for you:

A spider hug.

A spider hug.

A spider found for the first time in Canada: Myrmarachne formicaria (photo by V. Levesque-Beaudin, reproduced here with permission)

A jumping spider found for the first time in Canada: Myrmarachne formicaria (photo by V. Levesque-Beaudin, reproduced here with permission)

It started with the crickets

It all started with the crickets.

And it got a lot bigger than that.

I couple of weeks ago I received a gift from one of my MSc students – a lovely little tarantula that we affectionately call “Shelob”. My family was reasonably tolerant of this new addition. Shelob is a Chilean Rose-hair, a sort of pet that is sometimes referred to as a pet rock. But it’s a rock that needs feeding, hence the crickets. “Feeder crickets” are crafty little insects and despite my assumption that the terrarium for the crickets was sealed tightly, that was not the case. Unfortunately we had guests over for the weekend, and they were unimpressed by the cheeping crickets from under their bed in the middle of the night. And my teenage son was very angry one morning, having been woken up a bit too early by crickets in his bedroom*. The crickets were everywhere:

 

Crickets: Everywhere

Crickets: Everywhere

 

I'm not the only one with a cricket problem.

I’m not the only one with a cricket problem.

Living with an Entomologist (or Arachnologist) can be a challenge. It requires our partners / families / roommates / friends to be very tolerant of some odd behaviours. In my experience entomologists really know how to bring their work home with them. Our field of study is a passion that moves beyond the research lab or field site. It’s a passion that means we need to have sweep nets at home as well as at work, and most entomologists I know have a vial (or two) in their pocket, so they can collect their study specimens wherever they are (although we sometimes forget). This means, by extension, that our freezers at home become a place for frozen food AND dead insects. This is clearly something that is shared with entomologists around the world (which means, of course, that there are thousands and thousands of freezers in homes that act has a short-term specimen storage location as well as a place for ice cream and frozen peas – that may either impress you, or creep you out).

A typical freezer: note the food AND the vials with dead insects.

A typical freezer: note the food AND the vials with dead insects.

Another generality that emerges from these Tweets is that our partners, friends and/or families often have to be our ‘helpers’: holding up a thumb for scale, being a good landing spot for mosquitoes, or holding various entomological equipment while we scramble on hands and knees to grab that elusive specimen.

LizzyLowe

Holidays? They sure are fun when living with an entomologist…

The division between “work” and “play” is a difficult one to make for entomologists: there is a single-minded joy associated with collecting our study species, no matter where you are (honeymoon?) and no matter the time of day. It’s actually quite fun to run around the backyard with a sweep net, chasing *that* butterfly. A few years ago I recall seeing a very lovely butterfly heading from my backyard to the front yard – I was barbequing (in bare-feet) at the time – thankfully the trusty sweep net was right next to the house. I made a dash for it, hooting and hollering the whole time. The butterfly was quick – so much so that it was about 200 ft up the street before I collected it. My neighbors then became very well aware of what I “do”: the barefoot entomologist.

The final personal anecdote I will share is the “Specimens on the doorstep” phenomenon, shared among many entomologists: once you are known as the “bug person” in your town or city, BEWARE – people will drop off mason jars with odd critters in them. You know, the beetle that is eating Samantha’s roses, or the ant found in a neighbor’s dishwasher. So often I come home and one of my kids says to me “Dad – there’s another jar for you on the kitchen table”. I guess this isn’t all that normal…?

Fire ants at the foot of the bed. Oh my.

Fire ants at the foot of the bed. Oh my.

The hashtag #LivingWithAnEntomologist certainly took off: It’s clear that this concept hit a nerve, and that my own observations were actually quite general. SO many people tweeted their stories about what it’s like to live with an entomologist. Thank you to a most wonderful community of friends and colleagues.

To my dear and loving family: I’m sorry (But not really).

Cheep cheep.

——

* Note: I have some minor hearing loss, and despite EVERYONE telling me about chirping crickets in our house, I just don’t hear them. Lucky me, I suppose.

Spiderday (the seventh)

Welcome to spiderday. THE place to get all the stories about arachnids, from the past week. And boy oh boy it was a good week!

Let’s get started:

A spider from Singapore: it vibrates its web at high speed if it's threatened. Wow.

A spider from Singapore: it vibrates its web at high speed if it’s threatened. Wow. Photo by Chthoniid, reproduced here with permission.

A spider of sorts.

A spider of sorts.

A mitey good pun.

A mitey good pun.

Landscape structure, insect herbivory, and ecosystem services

I’m pleased to announce a new publication to come out of the lab, with lead author Dorothy Maguire and co-authored by Elena Bennett and Patrick James. In this work, Dorothy ponders and writes about the broader implications of insect herbivory. More specifically, how insect herbivory is affected by landscape connectivity (i.e., the degree to which habitats are linked to each other), and how plant-feeding insects may relate to ecosystem services (i.e., the values and services that humans get from our natural systems).

Female (l) and male (r) Gypsy moth, caught in the act.

Important insects when, as caterpillars, eat a lot of foliate: Female (l) and male (r) Gypsy moth, caught in the act.

We certainly know that insects can do all kinds of damage to plants in ecosystems, but do insects in more (or less) connected habitats do more damage? To address this question Dorothy scoured the literature and got the relatively unsatisfactory answer of “sometimes”: 49% of the papers suggest increased connectivity relates to more insect herbivory and 28% of the papers show less herbivory in more connected patches. The lack of a clear answer actually makes quite a bit of sense since every context can be quite different, and not all insects are equal. It is hard to generalize since effects in forests will not be the same as in fields, and insects that are out-breaking (i.e., with major population explosions) may be affected differently than non out-breaking species. Dorothy certainly found these contexts were important. The results were important to illustrate how we need to adapt any management options with close attention to both landscape feature and their interaction with the life-history of the herbivore.

The second part of Dorothy’s work delved deeper into the literature to ask about the effects of out-breaking versus non out-breaking herbivore species on a select suite of forest ecosystem services: effects on timber production, aesthetics, soil formation and Carbon sequestration. There were some interesting results of this and again, any particular effect of herbivory on an ecosystem service was highly sensitive to the outbreak status of the herbivore. For example, the aesthetics of a forest can be positively affected by low levels of herbivory since this may help create pleasant conditions for light infiltration to the forest floor. However, an out-breaking species may defoliate a tree more completely, thus reducing the aesthetic value. Another example is that low levels of herbivory may positively affect timber production because trees may show “compensatory” growth after light feeding by an insect. In contrast, timber production will be negatively affected by high levels of defoliation as this may reduce a tree’s ability to grow. Although some of these results may seem rather logical, Dorothy’s work was unique as it showed how the scientific literature supports the connections between a herbivore’s life-history and key ecosystem services.

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Visual representations of the hypothesized relationships between insect herbivory and ecosystem services. Specifically (a) timber production, (b) aesthetic value of forests. Graphs are divided into four sections representing positive and negative effects of herbivory on ES, during non-outbreak (low) vs. outbreak (high) levels of herbivory. Quadrants are coloured differently based on the hypothesized strength of the effect of herbivory on ES: weak (light grey), moderate (dark grey) and strong (black). Proposed relationships are derived from synthesis of the available literature. From Maguire et al.

The last part of the work was focused on building a conceptual framework – a framework that ties together landscape structure, the process of herbivory, and ecosystem services. This is meant to be a road map for any stakeholders with an interest in any or all of those factors. For example, should a forest manager be tasked with understanding how to increase or support a particular ecosystem service, she or he needs also to recognize how that service is tied to important processes such as herbivory, and the related connections to the broader landscape.

Screen Shot 2015-06-11 at 7.05.34 AM

This work is novel and important because it links the well known process of insect herbivory to concepts of ecosystem services and to the discipline of landscape ecology. The marrying of these areas is critically important as we face increasing pressures on our natural systems, and the complexity of the systems can be overwhelming. We hope this work piques more interest in this topic, and that the framework Dorothy provides is useful to all the stakeholders.

Reference:

Maguire, DY, PMA James, CM Buddle & EM Bennett Landscape connectivity and insect herbivory: A framework for understanding tradeoffs among ecosystem services. Global Ecology and Conservation. doi:10.1016/j.gecco.2015.05.006