The case of the missing genitalia: copulation costs for male spiders

This post is written by Chris Buddle (Associate Professor, McGill University). This article was originally published in “The Canadian Arachnologist” – a newsletter about Arachnology in Canada (this newsletter is no longer being published). 

Spider sex can be a dangerous and costly venture, the classic example being the (often) misunderstood act of sexual cannibalism (e.g., the black widow spider). However, many of the costs for males are not always so obvious: during copulation, the emboli of some male spiders may break off, which results in the male being unable to properly re-fill his palpal organ and mate again (Foelix 1996). Without this ability, the male’s future is essentially an early retirement. While sorting and identifying spiders for my dissertation research, I noticed that male Cybaeopsis euopla (a ‘hackledmesh’ weaver spider) seemed to frequently be missing one or both of their pedipalps.  Could this be another example of a copulation cost?

Looking to the literature, missing pedipalps are documented with some species – tiny males from the sexually dimorphic genus Tidarren (Theridiidae) will remove their own palps and this increases their running speed considerably (Ramos et al. 2004). Working with the same genus, Knofach and van Harten (2001) observed that females remove one of the male’s palps ‘after achieving genitalia coupling’. The female then proceeds to eat the male, while the detached palp acts as both a mating plug and continues to inseminate the female! Something similar happens with the species Nephilengys malabarensis and this fascinating biology was reported by science bloggers such as Ed Yong. In the wolf spider (Lycosidae) Pardosa milvina, frequent palpal losses were observed and effects on courtship and mating were studied by Lynam et al. (2006). Perhaps not surprisingly, these authors report that ‘intact males were less likely to be cannibalized and suffered fewer predatory attacks by females than autotomized males’.

With that background, I began counting the frequency of missing pedipalps for a sub-sample of the specimens of C. euopla. The objective was to assess the percentage of males were missing right, left, or both pedipalps and see if this related to phenology or other life-history events.

The samples came from a mixed-wood forest at the George Lake Field Station, located about 75 km NW of Edmonton, Alberta. This mature mixed-wood forest is dominated by trembling aspen and balsam poplar. Samples were collected using standard pitfall traps, and were part of several other projects on spider assemblages in mixed-wood boreal forests (e.g., see Buddle 2001).

Cybaeopsis euopla - lovely little spiders! (Photo by C. Buddle)

Cybaeopsis euopla – lovely little spiders! (Photo by C. Buddle)

Cybaeopis euopla (Amaurobiidae) (formerly Callioplus euoplus) is widespread in Canada, ranging from the Maritimes to the far north-west (Leech 1972). Males are about 3.5 to 5 mm in length, and are pale orange to light brown in colour. Specimens are typically collected from the leaf-litter of closed-canopy deciduous forests (Leech 1972; Buddle et al. 2000). From a sample of 653 male C. euopla, I found a total of 309 (or 47%) to be missing either one or both pedipalps. This is an impressive number, and essentially means that about half the males in the population are missing the very parts of their bodies that are required for reproduction. Of the 309 that were missing pedipalps, 124 were missing the left pedipalp, 97 were missing the right pedipalp, and 88 were missing both. In virtually all cases, the pedipalp was severed at the trochanter-femur joint. So the most plausible explanations for missing pedipalps are:

  • Pedipalp autotomy occurs during the act of copulation
  • The female may remove the pedipalps before, during or after copulation
  • C. euopla males may use their pedipalps in antagonistic courtship behaviours
  • Perhaps pedipalps are frequently used to grapple with aggressive prey, and are thus damaged.

It would be difficult to relate missing pedipalps to the act of copulation without detailed studies of courtship and copulation in C. euopla. However, the fate of pedipalps could be determined indirectly if the frequency of missing pedipalps increased during the reproductive period. The period of reproduction for ground-dwelling spiders, such as C. euopla, can be assessed from the peak activity period for male and female spiders, inferred from a passive sampling technique such as pitfall trapping. Using a larger data-set for male and female C. euopla collected by pitfall traps set at the George Lake Field Station, it is evident that males are most active early in the season (early May through the end of June) (Figure 1). Females were found throughout the spring and summer months over two years, with a slight increase in late June (Figure 1). These results generally agree with Leech (1972), who suggests May and June are the main periods of activity for C. euopla. Thus, it is inferred that this species will mate primarily in the spring in central Alberta.

Fig 1

The next step is to ask whether the frequency of missing pedipalps is related to the hypothesized mating period. This was done by calculating the average percentage of males with missing pedipalps as a function of sampling date (Figure 2). In both sampling years, the percentage of males with missing pedipalps increased as the season progressed (Figure 2). Although the sample size for July samples was low (12 individuals), the average number missing pedipalps was over 80%. Furthermore, the earliest sampling date in 1999 (6 May), which collected over 200 individuals, had the lowest average percentage of males with missing pedipalps (< 20%). These results indirectly suggest that as the season progresses, and the spiders mate, males begin to lose their pedipalps. I can therefore likely exclude the possibility that palpal loss is related to aggressive prey, and the explanation is likely related to courtship or copulation.

Fig 2

This small study has raised as many questions as it has answered, and there are certainly other explanations that I have failed to mention. I invite fellow Arachnologists to comment on the phenomenon of missing pedipalps in C. euopla, and in other species.  I suspect pedipalp loss is widespread, but seriously understudied. Given this importance of palps to the fitness of spiders, future research is certainly warranted.

References:

Buddle, C. (2001). Spiders (Araneae) associated with downed woody material in a deciduous forest in central Alberta, Canada Agricultural and Forest Entomology, 3 (4), 241-251 DOI: 10.1046/j.1461-9555.2001.00103.x

Buddle, C., Spence, J., & Langor, D. (2000). Succession of boreal forest spider assemblages following wildfire and harvesting Ecography, 23 (4), 424-436 DOI: 10.1034/j.1600-0587.2000.230405.x

Foelix, R.M. 1996. The Biology of Spiders. Oxford University Press.

Knoflach, B., & van Harten, A. (2001). Tidarren argo sp. nov. (Araneae: Theridiidae) and its exceptional copulatory behaviour: emasculation, male palpal organ as a mating plug and sexual cannibalism Journal of Zoology, 254 (4), 449-459 DOI: 10.1017/S0952836901000954

Leech, R. 1972. A revision of the nearctic Amaurobiidae (Arachnida: Araneida). Memoirs of the Entomological Society of Canada 84: 1-182.

Lynam, E., Owens, J., & Persons, M. (2006). The Influence of Pedipalp Autotomy on the Courtship and Mating Behavior of Pardosa milvina (Araneae: Lycosidae) Journal of Insect Behavior, 19 (1), 63-75 DOI: 10.1007/s10905-005-9008-x

Ramos, M. (2004). Overcoming an evolutionary conflict: Removal of a reproductive organ greatly increases locomotor performance Proceedings of the National Academy of Sciences, 101 (14), 4883-4887 DOI: 10.1073/pnas.0400324101

ResearchBlogging.org

Why Professors can’t relax (even if it will make us more productive)

This past weekend, as I was struggling to get some work done on a Sunday morning, I read Tony Schwartz’s opinion piece in the New York Times, titled “Relax! You’ll be more productive“.

I read it with curiosity and amusement.  I also discussed it with my wife, had a few discussions with people over twitter, and the more I thought about it, the more I decided it warranted a bit of a rant, and required placing Schwartz’s piece in the context of Academia.

Schwartz points out that “Human beings aren’t designed to expend energy continuously“, and we can be more productive (i.e., in the sense of doing work well) if we were able to find time to chill-out, relax, and maybe taking a nap would be a good idea.  This does make sense!  Being overtired can lead to mistakes, causes our the fuses to be short, and certainly can cause us to take longer at doing our jobs – even simple tasks can become difficult in the face of a life filled with too much of the ‘go go go’.    Why don’t Professors take mid-afternoon naps?  Heck, can’t tenured Professors relax and ‘do less’ whenever they want?

A nap?  Really?  BWAHAHAHA! This is priceless.  How abut a dose of reality.

I am a Professor, and this job is absolutely wonderful, but it does require (yes, REQUIRE) a busy schedule and a lot of time.   Time management is a big part of my job, and the days are full of teaching responsibilities, grant-writing, meetings with students, administrative responsibilities and writing manuscripts.  Contrary to what Forbes might lead you to believe, the life of an Academic is not stress-free and is not all tweed-jackets, and hobnobbing at the Faculty club.  A lot of the stress is positive stress, but there is stress, and finding time to relax during the workday is an impossibility given the current context of University.

I fully appreciate some of the ideas behind Schwartz’s piece: taking a mid-day stroll outside (like Darwin did each day!) , or a quick nap in the afternoon, would be good for me, and would probably help with productivity but the reality is that there is no time.  And I just can’t make the time appear.  It’s the ultimate limiting resource.  When I do have time that is freed up during the work day, it gets filled with tasks that are deemed important but not urgent.

How about the the #worklifebalance.  Many people with jobs also have families and commitments at home that compete with the resources of time and energy.

Is this familiar to you?

Time to get the kids to dance class and Music lessons.  Homework hell around the kitchen table?  Phew.  Dinner’s done. How about kitchen clean-up?  Who will fold the laundry?  ….finally, it’s time to fall exhausted on the couch at the end of the day.  Ahhhh sleep…glorious sleep.  6 AM!  Up we get, let’s get lunches ready!  Where’s that permission form?  The bus is coming, you’re late!  Shoot – I’m late too.  Gotta run… have a great day!

My wife pointed out that Schwartz’s argument really doesn’t apply to jobs in which it takes X amount of time to do a task, and if you are in a business that is dependent on consumers buying your product, if you sell Y more units of your product, it will take X x Y amount of time to get the product out the door.  There is not really a choice – you can’t relax and do less,  If you did less, you won’t have a sustainable business.  As some of the reader’s comments in Schwartz’s piece state: ‘relaxing’ is simply a luxury that most people can’t afford.

I like this quote from Schwartz’s piece: Paradoxically, the best way to get more done may be to spend more time doing less

YES!  I do agree.  I buy into the ‘why‘ but I can’t see the ‘how‘: if less time is spent on one task, this frees up a bit of time, and it will get filled right away. (and never mind the fact that GUILT will come into play – I really would feel rather guilty if I shut my office door for a 20 minute shut-eye each afternoon…even if that chair is in the corner of my office is really, really comfortable).

A nice place for a nap.

A nice place for a nap.

Academic Institutions could be model systems for re-thinking the workplace and how to consider ways to help employees  find time to ‘relax’ on the job, and that will surely have many benefits.  This will, however, require a paradigm shift, and require a complete re-thinking of the ways the tenure-track system works, and the level of expectations put on Academics.  This could be a great discussion to have, and let’s have it.  But let’s not start this discussion with a goal that is untenable. I am quite sure that my colleagues would have a good chuckle if they were encouraged to ‘relax’ and have a little downtime during the workday.

Let’s start with some things that are a bit smaller and more realistic.

Let’s work our timetables so that lunch time can be free of classes; let’s find ways to encourage people to eat in a common area instead of in front of their computer.  Let’s make sure offices, labs and coffee machines are suitably arranged so that people move around, communicate, and find a bit of time to sit with colleagues and students over a cup of tea.  Let’s be sure that Chairs and Deans give tenure-track staff the right kind of mentorship so they can be productive on the right kind of tasks, and the flexibility and support so they can find the right balance between the various duties of academia.  Let’s recognize, up front, that negative stress, overwork, e-mail hell, and pressures on time are real problems that require real solutions.  If Academic institutions want to be places of higher learning, there must be support and a recognition that ‘down time’ to ponder, discuss and be curious is time well spent.

Well, with that, I’m going to go out for a walk – actually a run – a run to the lecture hall because I’m running late.

Postscripts:

First, I sincerely hope this post does not come off as sounding like I’m whining or complaining. I’m not complaining – I love my job and I wouldn’t trade it for anything. 

Second, you might ask how I found time to write this blog post.  That is more difficult to address – sometimes the really fun things to do can be done quickly, and it seems relatively easy to find a few minutes to write something I am passionate about.  I also seem to get some very positive energy from this exercise.  Hmmm … maybe writing a blog post is my way to relax?

Assessing five decades of change in a high Arctic parasitoid community

As my colleague Terry Wheeler mentioned on his blog, our Northern Biodiversity Program team is thrilled to see post-doc Laura Timms‘s paper about Arctic parasitoid wasps published in Ecography!  Our team worked on Ellesmere Island, Nunavut, in 2010, and compared parasitoid wasps to historical collections from the same site that were made in 1961-65, 1980-82, and 1989-92. Parasitoid wasps are at the top of the insect food chain: they lay eggs inside or on top of other arthropods and the wasp larvae emerge after consuming their hosts – a gruesome but very common lifestyle for many types of wasps.  Species at higher trophic levels, such as these parasitoid wasps, are often the first to respond to new environmental pressures, including the climate change that is occurring rapidly in Arctic systems.

Laura identified a LOT of wasps, recorded the type of host attacked (e.g. plant-feeding hosts versus hosts that are predators), and the body size of two species of wasps that were commonly collected in all time periods.  We found no clear pattern of change in most aspects of the parasitoid wasp community on Ellesmere Island over past 50 years, even though temperature and precipitation have increased significantly during the same period. However, there were some signs that parasitoids of plant-feeding insects may be more affected more than other groups: one common parasitoid species that was abundant in 1960s hasn’t been collected since then, and the community in the 2010 study contained fewer parasitoids of plant-feeding insects than previous studies.

Screen shot 2013-01-28 at 10.52.40 AM

Some members of the Northern Biodiversity Program working in the Yukon in 2012. (l-r, Chris Buddle, Laura Timms, Crystal Ernst and Katie Sim)

Laura takes it as a good sign that no major changes in the ecology of the high Arctic parasitoid community have been observed, but isn’t taking it for granted that the community will remain unaffected for long.  At 82°N, Ellesmere Island is relatively isolated, but other research has found that parasitoid communities further south are changing dramatically (Fernandez-Triana et al 2011).

Laura has the following comment about our work: “We hope that our findings will be used as baseline data for ongoing monitoring on Ellesmere Island”, said Timms.  “We know so little about these high Arctic insect communities, we should learn as much as possible about them while they are still intact.

References

Timms, L., Bennett, A., Buddle, C., & Wheeler, T. (2013). Assessing five decades of change in a high Arctic parasitoid community Ecography DOI: 10.1111/j.1600-0587.2012.00278.x

Fernandez-Triana, J., Smith, M., Boudreault, C., Goulet, H., Hebert, P., Smith, A., & Roughley, R. (2011). A Poorly Known High-Latitude Parasitoid Wasp Community: Unexpected Diversity and Dramatic Changes through Time PLoS ONE, 6 (8) DOI: 10.1371/journal.pone.0023719

Where did all the spiderlings go? A story about egg-sac parasitism in Arctic wolf spiders

This week we are in a deep freeze in the Montreal area, so it seems somewhat fitting to discuss Arctic spiders.  I’ve discussed the life-history of Arctic wolf spiders (Lycosidae) before, specifically in the context of high densities of wolf spiders on the tundra.    Much of this work was done with my former PhD student Joseph Bowden.  The latest paper from his work was published last autumn, and was titled ‘Egg sac parasitism of Arctic wolf spiders (Araneae: Lycosidae) from northwestern North America‘. In this work we document the rates of egg sac parasitism by Ichneumonidae wasps in the genus GelisThese wasps are fascinating, and we have found them to be very common on the tundra.  There are often multiple wasps in a single egg sac, and as is typical with Gelis, they leave nothing behind: all eggs within an egg sac are consumed.  After fully developed, the adult wasps pop out of the egg sac; the Gelis adults we encountered had both winged forms and wingless females, the latter superficially resembling ants.

A Gelis emerging from a wolf spider egg sac. Photo by Crystal Ernst, reproduced here with permission.

A Gelis emerging from a wolf spider egg sac. Photo by Crystal Ernst, reproduced here with permission.

The rates of parasitism of Pardosa egg sacs (by Gelis) were, at some sites, extremely high.  In some cases over 50% of the wolf spider egg sacs were parasitized.  Stated another way,  half of all the females encountered with egg sacs had zero fecundity because the female was  carrying around wasps within the egg sac instead of spider eggs.

It’s quite interesting to think about these wingless Gelis femalesafter emerging from egg sacs, they end up wandering around the tundra in search of hosts.  Spiders with egg sacs must be encountered frequently enough for the wasps to grab on to a passing wolf spider in order to parasitize the egg sac.  Recall, densities of wolf spiders can be very high in the Arctic (4,000 per hectare, at least).  Hmmm…. this is all starting to fit… high densities of wolf spiders support high rates of egg parasitism and these wasps can ‘afford’ to be wingless since their hosts are frequently encountered:  an interesting feedback loop!   We can also speculate about large-scale gradients in diversity – many Ichneudmonidae show high diversity in northern regions.  Within Gelis, it’s a good bet that they will find many suitable spider hosts in these environments.

Looking down the microscope - all those Gelis!

Looking down the microscope – all those Gelis!

So, how extreme are these rates of egg parasitism?  Looking at some of the literature, there are certainly a number of papers about  wasps that parasitize spider egg sacs.  Cobb & Cobb (2004) studied two Pardosa species in Idaho, and recorded a egg parasitism rate of about 15% (by Gelis wasps and wasps in the genus Baeus [Sceleonidae]). Van Baarlen et al (1994) studied egg parasitism in European Linyphiidae spiders and their maximum rates of parasitism were about 30%.   Finch (2005) did a detailed study of four spiders species (non-Lycosidae) and rates of egg parasitism varied between 5% up to as high as 60% in an Agroeca species.

Our documented parasitism rates for Arctic wolf spiders are certainly quite high (for Lycosidae), but not out of the range of other published studies for non-Lycosidae.  I do wonder whether we will continue to find high egg parasitism rates if more species were examined in detail – certainly a fertile area of study.  Related to this, what are the population-level consequences of this interaction?  What is the relationship between spider densities and parasitism rates?  Although Joe and I did try to speculate on this, our data are preliminary – again, a key area for future research.

Screen shot 2013-01-23 at 12.20.40 PM

In the Arctic context, we will continue to uncover fascinating food-web dynamics.  Our research group has already been thinking seriously about this – Crystal Ernst has written a nice post about the idea of an ‘inverse trophic web’ (i.e., predator-dominated) in the Arctic, and a fair amount of my future research will pursue this avenue of research.

Pique your interest…?  Why not think about graduate school in my lab, and study Arctic arthropod biodiversity?

References:

Bowden, J., & Buddle, C. (2012). Egg sac parasitism of Arctic wolf spiders (Araneae: Lycosidae) from northwestern North America Journal of Arachnology, 40 (3), 348-350 DOI: 10.1636/P11-50.1

Cobb, LM & Cobb VA (2004). Occurrence of parasitoid wasps, Baeus sp and Gelis sp., in the egg sacs of the wolf spiders Pardosa moesta and Pardosa sternalis (Araneae: Lycosidae) in southeastern Idaho. Canadian Field Naturalist 118(1); 122-123.

Baarlen, P., Sunderland, K., & Topping, C. (1994). Eggsac parasitism of money spiders (Araneae, Linyphiidae) in cereals, with a simple method for estimating percentage parasitism of spp. eggsacs by Hymenoptera Journal of Applied Entomology, 118 (1-5), 217-223 DOI: 10.1111/j.1439-0418.1994.tb00797.x

Finch, O. (2005). The parasitoid complex and parasitoid-induced mortality of spiders (Araneae) in a Central European woodland Journal of Natural History, 39 (25), 2339-2354 DOI: 10.1080/00222930500101720

ResearchBlogging.org

Taxonomic sufficiency in biodiversity research: Is it always necessary to identify species?

It’s been a successful few weeks in the lab!  Two weeks ago I promoted an exciting paper about spider silk and herbivory and just after that paper come out, another publication from our lab was published, titled: “Does species-level resolution matter? Taxonomic sufficiency in terrestrial arthropod biodiversity studies“.  This paper evolved out of a past graduate-level class in Forest Entomology at McGill, and was re-worked and re-written by post-doc Laura Timms, former Phd student Joseph Bowden, and my colleague Keith Summerville.

Let me provide a plain language summary of this work and I will also touch upon some of the controversy that has arisen because of this paper:

Biodiversity science is about the discovery and description of all the different kinds (species) of organisms living on our planet.  It is a vitally important area of research because different species play important roles in our ecosystems, and as a consequence, are important to us.  The different number of species in an area can also inform us about how we might be harming or helping ecosystems.  This is an active area of study in the context of forestry, since some forest practices (for example, cutting all the trees down in an area) can cause changes in the number of species (and whether they are rare or common) and these changes can inform us about whether our forestry practices are harming our ecosystems.  All of this kind of work, however, depends on the ability of scientists to collect, sort, and identify different kinds of species.  Since most described species on the planet are Arthropods (e.g., spiders, insects, and their relatives), these animals are often used as a way to indicate how biodiversity might be affected by environmental change.  However, there is a problem: it takes a very long time to identify different arthropods, and it is costly and difficult – requiring highly specialized training, by people known as taxonomists.  In our research project, we asked whether not you always need to know the exact differences between insects and spiders  in order to tell if a disturbance is affecting biodiversity.  We did this by looking at a series of data-sets about beetles (Coleoptera), moths & butterflies (Lepidoptera), and spiders (Araneae). These data-sets were from past research projects about how forest disturbance affects biodiversity.

Here is how we did the work: Different kinds of organisms are classified using a two-part name:  the genus and the species.  There can be many different species within one genus.  You can then classify different genera (the plural of genus) into grouping called Families.  For example, all wolf spiders are in the Family Lycosidae.  A common genus within this family is Pardosa – there are dozens of species of Pardosa in Canada; Pardosa mackenziana, Pardosa moesta, Pardosa hyperborea, etc.  We first took our big data-sets and using the lowest level of naming (the species) we asked whether forest disturbance affected biodiversity.  We then grouped all our species into their respective genera -this meant that the data-sets got smaller (i.e., there are necessarily fewer genera than species).  We did the same analysis to see if we could still get a signal about the effects of disturbance on biodiversity, but now with the ‘reduced’ data.  We did this again at the family level.  We did this because we wanted to know if you could take a short-cut. Stated another way, if you don’t have the time or ability to figure out all the species in your research project, can you still see if there is an effect of forestry on biodiversity?

A wolf spider (Lycosidae)

A wolf spider – do you need to know its name?

Our results showed that in most cases, you do not need to know the species identity to see the effects of forestry practices on the biodiversity of spiders, beetles and moths & butterflies – you do not get as clear answers when things were grouped into Families, but the datasets with species grouped into genera were almost as good as when you group things into species.  This was surprising, because an assumption in biodiversity science is that species-level identifications are necessary and should be the ‘gold standard’ for this kind of research.  We showed that in many cases, you can get your answer by identifying arthropods to the generic level:  this can save you a lot of time (and money).   Some researchers (including taxonomists) may not be thrilled with this result as it might suggest that species are not important, and specialized taxonomic knowledge is not essential to complete biodiversity research.  This is certainly not the case, which leads me to the caveats:

1) Our results do not mean species are not important!  Instead, we are saying that if there are logistical and financial constraints, you might be able to answer your research question without having to identify all the species.   If you have a project about large-scale disturbance and are looking to see whether there are any broad affects on biodiversity, our approach might work.   However, you might miss some subtle effects, so this approach must be taken with caution.  Although our suggestion is a short-cut, it would still be important to save all the samples, and at a later time (as money and expertise permits) the species could be determined.

2) Our study is specifically geared towards research about insects and spiders in relation to large-scale forestry disturbances.  We are not saying that this will work in all situations and with all different kinds of organisms! The context is important.  Related to this, if an overarching research question is about species in an ecosystem, species-level identifications are essential.  Everything depends on the research question and the research context.

3) This general approach that we have discussed is highly dependent on what kind of organisms you are studying.  If you are working with a group of organisms that do not have too many different species within a genus, our approach may work.  If, however, there are many species within a single genus, our suggestion will not work as well.  Therefore, a researcher should look at the general relationship between the number of species per genus for their study organisms and use this ratio as a guide when thinking about taking the short-cut that we discussed in the research.

In sum, we are quite excited about this research – we think it will provide more opportunities for biodiversity projects to get done, and will help answer certain research questions when there are substantial constraints on time and money.  This is one way to be pragmatic about biodiversity research.

Please share your thoughts!

Reference:

Timms, L., Bowden, J., Summerville, K., & Buddle, C. (2012). Does species-level resolution matter? Taxonomic sufficiency in terrestrial arthropod biodiversity studies Insect Conservation and Diversity DOI: 10.1111/icad.12004

Trying to find Profs at a University? Just 5.4 clicks away…

Here’s a rant for you.

Yesterday I was trying to find lists of Entomology researchers and staff at various Universities.  This turned out to be a very frustrating experience, and I decided to follow up on this a little more closely.  I pretended I was a potential graduate student who was interested in Entomology, but who did not necessarily know who (i.e., by name) to look for.  So, I went to main University homepages and attempted to navigate my way to a list of faculty within, for example, a Department of Entomology.

This was a stunningly frustrating and annoying process.  In my largely unscientific approach, it took me an average of 5.4 clicks (range 3 to 7) to get to Faculty listings in a series of Canadian and US Universities (my sample size was 20).  The best was Ohio State and Iowa State – in three clicks I was able to get to the list of Entomology Faculty.  These worked – essentially you move from University Page to Academics, where there is a complete list of Departments and from the Departmental page there is a clear link to ‘people’.  The most clicks was seven, and of these, Penn State was the worst because once you got to the Department of Entomology, you still could not easily access a list of people and had to instead navigate through ‘research areas’.   At my own institution, it took me 7 clicks to find a list of faculty within my department (yikes!).  The most significant challenge of this exercise was to ‘guess’ what College or Faculty (or Department) to navigate to (Faculty of Science?  College of Life Sciences and Agriculture?)

Department of Entomology at Iowa State - a winner!

Department of Entomology at Iowa State – a winner!

You might argue this is useless exercise, because people will just use Google.  However, if you don’t know who you are looking for you are forced to deal with University websites.

I tweeted about this issue yesterday, and Alex Wild and Crystal Ernst suggested this is one key reason why researchers need to set up their own profiles through Google Scholar profiles (e.g., here is Alex’s) or through their own websites.  I agree with this, but it is still important that you can be found at your own institution!  

Think of this again in terms of a potential graduate student searching for staff listings in an area of study that interests them.  How quickly will someone give up and seek a site that is easier to navigate?  

A bigger question:  who is the audience for a University website?  Donors?  Alumni? Staff?  I would argue the audience is students, and as such, these sites must be designed for students – and in many cases (especially for potential MSc and PhD students), students are looking for people: informative and easy-to-find listings of faculty should be a priority.

In sum, University websites are not easy to navigate.  Try to find a list of people?  Good luck.  

Fear factor: spider silk reduces plant damage

Today I am excited to report on research published with Ann Rypstra, a most wonderful person and exceptional spider ecologist.  Here’s the take home message from our paper, titled  ”Spider silk reduces insect herbivory” (Rypstra & Buddle 2013):

In the presence of spider silk, insect herbivores eat less plant material  - and the spider doesn’t have to be around to see this effect!

A spider’s web, made with silk. Photo courtesy of M. Larrivee (reproduced here, with permission)

Here’s a plain-language summary of the research:

Spiders are important in agricultural systems because they eat many insect pests that in turn eat valuable crops.  Spiders also leave behind silk as they move through an agricultural field – sometimes this silk is there because it was part of a web that was constructed to catch prey, or sometimes spiders leave silk in the form of a ‘drag-line’ – a kind of silk that acts as a safety-line for a spider.  Whatever the means, the agricultural landscape contains plants, their insect pests, spiders and spider silk.  In this work, we wondered whether  silk, in the absence of a spider, would still cause the insect pests to be wary, and feed differently than if there was no spider silk in their environment.  

We used laboratory and field-based experiments for this research, and we used two pest species – the Japanese beetle and the Mexican bean beetle.  These pests were allowed to eat either leaflets or whole plants of bush-style snap beans.  The plants or leaflets were either left alone, or were adorned with five strands of spider silk or with five strands of silkworm silk.  We included the silkworm silk (i.e, produced from the silkworm moth) because we were curious about whether the beetles might respond to ANY silk instead of silk produced specifically by spiders.  To extract the spider silk, we allowed a long-jawed orb-web spider to hang from its drag-line, and we wound its silk around a stick as the spider bobbed up and down – in this way we could get enough silk for the experiments. We found that when spider silk was on the plants, the insects inflicted less damage compared to when there was no silk.  The silkworm silk also caused the insects to feed less, but the effect with silkworm silk was less than with spider silk.  We also wondered whether this response could just be because the silk got in the way of the beetles, and so we did some experiments with human hair, and a strand of kevlar – these are both ‘silk-like’ strands but since they did not come from an insect or spider, would only represent the physical nature of the silk rather than have any other chemicals or smells from the silk produced by a insect or spider.  This additional experiment showed us the same results: the insect pests still ate less when on plants containing silkworm silk or spider silk compared to those with the kevlar or human hair.  

All these experiments, combined, tell us that there is something very special about spider silk, and it causes pest insects to eat less plants.  In ecology this is dubbed an ‘indirect’ effect – the spiders do not have to eat a pest insect to cause it to change its behaviour! It is also called a ‘non-consumptive effect’ – meaning the effect of the spider on its prey is not through the act of eating the prey, but rather by changing prey behaviour by other means.  This work is fascinating because it shows that spiders have a much more important role in agricultural systems than we realized before: spiders do not have to be present to cause insects pests to eat less – as long as they were there, and produced silk as they moved through their environment, their potential prey will live in a ‘landscape of fear’.  Or, the insect pest is living in fear of spiders because of their silk. 

Here is a more technical summary, placed within a broader ecological context:

Tetragnatha – a long-jawed orb-web spider. Photo by Lee Jaszlics, reproduced here with permission

The pest insects (the beetles) in our study system recognize the silk is coming from a potential predator (the spider), and this means they alter their behaviour, or LIVE IN FEAR!  This work fits within the broader literature about the landscape of fear (e.g. see Laundré et al. 2012), or ecology of fear sensu Brown et al. (1999). The idea here is that prey are shifting their behaviours depending on predators, and so the prey’s overall ‘landscape’ is peaks and valleys related to the strength and type of interactions (direct or indirect) caused by the predator.  To anthropomophize this even more: fear induces behavioural changes in prey; they are scared and this fear has real and measurable effects.

Although a lot of this kind of research is with vertebrates, there are some interesting examples from the arthropod world.  One recent example is by Hawlena et al. (2012) – in this work, grasshoppers that were raised in an environment of fear (via continual exposure to spiders whose chelicerae were glued shut) had different Carbon:Nitrogen ratio in their bodies relative to controls, and this affected plant litter decomposition.  So, the ‘fear factor’ changed the elemental composition of grasshopper’s bodies and eventually this affected the decomposition process!  In Hlivko & Rypstra’s (2003) work, a leaf-eating beetle, when exposed to a range of cues produced by spiders (this included feces, silk and other chemicals) ate less plant biomass compared to controls, and the strongest effect was from cues of the largest spider.   Within the context of fear – the largest (and presumably the most feared) spider, can elicit a response in its prey which results in an affect on plant biomass.  Our paper is taking this one more level, and focuses on the silk as a key ‘cue’ that induces the behavioural change in the prey.

Our results show that insect pests that feed on plants in agroecosystems may be living in a landscape of fear that is brought on by one of the most common substances produced our eight-legged friends…the silk.  This silk acts as an important cue for the insect pests and they eat less plant material because of this.   This research also shows the added value of spiders in agroecosystems; conservation of spiders, or even habitat manipulations to encourage spiders to live in agroecosystems, could have many pay-offs.

The study species in our research: Tetragnatha (photo courtesy of M. Larrivee, reproduced here with permission)

Thanks to Max Larrivee and Lee Jaszlics for permission to use their wonderful photographs!

References:

Brown, J., Laundré, J., Gurung, M., & Laundre, J. (1999). The Ecology of Fear: Optimal Foraging, Game Theory, and Trophic Interactions Journal of Mammalogy, 80 (2) DOI: 10.2307/1383287

Hawlena, D., Strickland, M., Bradford, M., & Schmitz, O. (2012). Fear of Predation Slows Plant-Litter Decomposition Science, 336 (6087), 1434-1438 DOI: 10.1126/science.1220097

Hlivko, J., & Rypstra, A. (2003). Spiders Reduce Herbivory: Nonlethal Effects of Spiders on the Consumption of Soybean Leaves by Beetle Pests Annals of the Entomological Society of America, 96 (6), 914-919 DOI: 10.1603/0013-8746(2003)096[0914:SRHNEO]2.0.CO;2

Laundre, J., Hernandez, L., & Ripple, W. (2010). The Landscape of Fear: Ecological Implications of Being Afraid~!2009-09-09~!2009-11-16~!2010-02-02~! The Open Ecology Journal, 3 (3), 1-7 DOI: 10.2174/1874213001003030001

Rypstra, A., & Buddle, C.M. (2012). Spider silk reduces insect herbivory Biology Letters, 9 (1), 20120948-20120948 DOI: 10.1098/rsbl.2012.0948

ResearchBlogging.org

Plain-language summary of research results: Mites, rotten wood, and forests

Last week I wrote a post that outlined a proposal to require plain-language summaries of all research papers. I decided that I would start to do this with my own papers to see how difficult it might be, and also to see if this could help to make the research more accessible to a broad audience.

So… here it goes. This is a summary of paper written with my former MSc student Andrea Dechene, about mites, forests and fallen logs:

         Mites are small animals, closely related to ticks and spiders. They are so small that it is very difficult to see them without the help of a magnifying glass or microscope. There are many kinds of mites, and they are found almost everywhere, including forests. Mites are important in forests because they can affect how leaves and rotten wood decompose on the forest floor. 

          In this research, we studied whether certain kinds of mites were associated with logs that were decomposing on the forest floor, and we did this work in north-western Quebec. We collected mites living in the wood, on the ground near the wood, and on the forest floor about 1 m away from logs. Mites were collected by taking a handful of soil, leaves or rotten wood, putting this in a zip-lock bag, and then the samples were taken to a laboratory. In the lab, these handfuls of soil, leaves and wood were placed on a bench below a light. Mites do not like bright lights and they try to get away by moving away from the light – in this case, they move downward where they think it is safe. The samples are on a screen, however, and the mites fall through the screen and into a jar that contains a liquid that will kill them. These jars are taken to a different lab where the mites are inspected with the help of a microscope. With the help of books and other resources, we could figure out all the different kinds of mites and sort them into their different varieties.  Some kinds had names while other ones did not 

         We discovered 80 different kinds of mites and over 15,000 mites, in total, fell into the jars. That means a lot of mites live in forests! We also discovered that different kinds of mites live in the rotten wood compared to the forest floor and compared to the leaves. We found that the most different kinds of mites actually lived in the leaves that were over top of very, very rotten wood. This is an exciting result because nobody figured this out before, and it means that long after wood decomposes, there are still animals that ‘remember’ the wood was there and are using it as a suitable place to live. Lots of scientists have worked on rotten wood and it is well known that wood is very important for many animals and plants in a forest. Our work is different because we looked at some of the tiny animals in forests and they are also telling us that rotten wood is a good place to live. Next time you see a fallen tree, remember that many kinds of mites depend on that tree and you should leave it where it is.

Mites live here.

Phew.

By the way, here is the actual Abstract from that paper:

The removal of timber during harvesting substantially reduces important invertebrate habitat, most noticeably microhabitats associated with fallen trees. Oribatid mite diversity in downed woody material (DWM) using species-level data has not been well studied. We investigated the influence of decaying logs on the spatial distribution of oribatid mites on the forest floor at the sylviculture et aménagement forestiers écosystémique (SAFE) research station in the Abitibi region in NW Québec. In June 2006, six aspen logs were selected for study, and samples were taken at three distances for each log: directly on top of the log (ON), directly beside the log (ADJ) and at least one metre away from the log and any other fallen wood (AWAY). Samples ON logs consisted of a litter layer sample, an upper wood sample and an inner wood sample. Samples at the ADJ and AWAY distances consisted of litter samples and soil cores. The highest species richness was collected ON logs, and logs harboured a distinct oribatid species composition compared to nearby forest floor. There were species-specific changes in abundance with increasing distance away from DWM, which indicates an influence of DWM in structuring oribatid assemblages on the forest floor. Additionally, each layer (litter, wood and soil) exhibited a unique species composition and hosted a different diversity of oribatid mites. This study further highlights the importance of DWM to forest biodiversity by creating habitat for unique assemblages of oribatid mites.

The Extractor – getting mites from the samples

Thoughts? –I kind of like the plain-language summary.

The plain language summary was not easy to write and it took a lot of words to explain certain things. Despite the challenge, I’m convinced it was a worthwhile use of time.  Please consider doing this with your own papers!  

Reference:

Dechene, A. and C. M. Buddle. 2010. Decomposing logs increase oribatid mite assemblage diversity in mixedwood boreal forest. Biodiv. Cons. 19: 237-256. http://www.springerlink.com/content/r3681l0185620311/

Science outreach: plain-language summaries for all research papers

1) Scientists do really interesting things.

2) Scientists have a responsibility to disseminate their results.

3) Scientists do not publish in an accessible format.

This is a really, really big problem.

Scientific research is largely funded by public money, and it can be argued that scientists have a responsibility to make their work accessible to the public (and scientists are particularly well suited for outreach activities!).  The main platform for disseminating research results is the peer-reviewed journal paper and this is not ideal.  Let’s be honest – these kinds of publications are often very specialized, full of jargon, and unreadable to most (even other scientists).  Many papers are also behind pay-walls, making them even less accessible to people outside of certain institutions.

Earlier this week I attended a scientific conference (the annual meeting of the Entomological Society of Canada) and as part of this conference I was invited to speak in a symposium that was about social media in science.  It was a great session and some of my favourite social media mentors were also speaking at the symposium, including Adrian Thyssemacromite, the Bug Geek, and Biodiversity in Focus.   As I was preparing that talk the week before, I was also madly finishing a grant application, and in that application I was require to write a plain-language summary of my proposed research.  The granting agency uses this ‘summary for public release’ as a way to communicate research to the public.  Taxpayers fund the research and they might want to know where their money is going; the granting agency has found one way to communicate this information in a clever and effective manner.

…………………………..Eureka!

Here is the proposal:  Every scientific paper published in a peer-reviewed journal must be accompanied by a short, plain-language summary of the work.

This summary would be placed on-line, free for everyone to read.  It would be concise, clear, free of jargon, and highlight why the work was done, how it was done, and what was discovered.

Here are some examples of how these plain-language summaries could be used:

1. Media: Media offices at Universities are constantly interested in promoting fantastic work by their Professors.  This work, however, is often not accessible and it can be a lengthy process to put together a press release (how easy is it to track down a researcher?).  A plain-language summary written by the researcher would be readable, clear, accessible, and an easy way to start the process of promoting research activities occurring at Universities.

2. Blogging: I am a regular blogger, and always happy to promote the research occurring within my laboratory, the laboratories of colleagues, or just discussing interesting scientific papers that I have read.  If I had plain-language summaries to access, it would make the process that much easier, and help facilitate timely communication with the public about recently published work.  Other science bloggers could also pick up on these summaries for their own writing.

3. Publishers & Editors:  As an editor-in-chief for a scientific journal, I sometimes look for ways to promote great papers, and promote the journal to a larger audience.  If I was able to peruse the summaries for public release,  this would make the process much easier.  Publishers could also take text from these summaries, put together a press release or blog post, and also promote research results from their journals based on particularly interesting papers and findings.

4. For Everyone: In my experience, people outside my area of expertise are always keen to hear about research activities.    It’s sometimes a challenge for me to explain my research results, and if I was always doing plain-language summaries, this would get easier.    The audience for research results can be as big as you can imagine: high school students, friends, family, colleagues, Departmental chairs, graduate students, journalists, libraries, etc…  Finally,  the Bug Geek has a great post about the challenges of talking science to 10-year olds:  it is hard to do, but important.  We need practice.  These summaries will help.

The procedure for getting plain language summaries could be quite simple.  When an author submits the final revisions on a scientific publication, they would be required to write a short plain-language summary.  I would like to think that publishers would be willing to incorporate this (simple) step into the on-line systems for manuscript processing, and be willing to post these, as open-access, on their websites, possibly paired with Abstracts.   These summaries would not diminish the value of the actual peer-reviewed papers – it would probably help increase readership since these summaries would help people find the work they are actually looking for, and give them a doorway into the scientific literature.

Let’s make this happen.  

It will be an effective way to do science outreach.

 Please comment, share the idea, and let’s see this idea grow.  

The transformative power of social media: blogs and tweets in a university course

As part of my field biology course this term, groups of students are working on research projects related to observing species in their natural setting – a Natural History‘ project. Students are working in groups of 4-6, and each group is doing a focused project about a particular species (or group of species) including the following:  American beech trees, sugar maple trees, hemlock trees, shelf fungi, aquatic macroinvertebrates, litter-dwelling arthropods, small mammals, the American crow and chickadees. 

The first part of this project involves providing an overview of the natural history of their study species, and this overview is being released in the form of a scientific blog post.  Starting today, and for the next three weeks, the nine blog posts will be released on the following site.  (Today’s release is all about American beech Trees).

ENVB222 – the first post

I have opted to use blog posts, as one form of social media, as a direct communication tool in this undergraduate course.  This opens the work up to the broadest audience possible, and students have a lot more people to write for than just their instructors.  I believe this will increase the quality of the writing since the stakes are quite high: experts on their topics will be able to read and comment on their posts.    The students are encouraged to connect with the broader scientific community and seek input on their study species.    Another reason to use social media is to allow the classroom work to move outside the walls of Academia.  Students have told me that they are inspired by the idea of taking what they are learning and seeing how it is valued outside the (typically) insular classroom activities.

The use of social media in the classroom would not be complete without Twitter! The groups have set up twitter accounts, and within 48 hours of their posts going live, they will be tweeting a series of facts related to their study species!  This is another informative, collaborative and fun way to seek input into their projects, and a way to bring what they have learned out to the broader community of biologists.  Follow along!  You can simply use the hashtag #ENVB222 to track the tweets related to the project. (by the way, you can follow the Beech tee group @BBDteam ).  Here are a couple of examples of other tweets:

A tweet from the litter dwellers…

The Crow group’s tweet

Students have already started to connect with scientists from other institutions – they are already feeling part of something bigger.  For example, students in a field biology course at the University of Hull in the UK have connected with McGill students – the students from the two institutions can share connect, collaborate and share their experiences.  This can be done easily through #hashtags:

A re-tweet to Hull Students, from their Professor (Graham Scott)

So far this social media experiment in the classroom is inspiring, exciting, and leveraging real tools as a way to take the teaching and learning experience to a new level.  However, it will only work if their blogs are read, critiqued, and discussed with the broader community.  So, I encourage you to follow along and take part in this activity.  You are all invited.

Community.  Sharing.  Collaboration. Outreach. Communication.

This is the power of social media.