A walk in the woods

Last week I had the opportunity to visit my PhD student Dorothy Maguire at her field sites south of Montreal.  It was a glorious summer day, and given the construction holiday in Quebec, the travel time was quick and effortless (for Montrealers, you know what I am talking about!).  I have briefly described Dorothy’s research in a previous post, and during the field visit, I was able to see Dorothy and her two field assistants ‘in action’.  This included checking samples from an aerial malaise trap, beating the foliage (for herbivores) in the forest canopy, and checking contents of a Lindgren funnel (set up in the canopy to collect flying insects, including beetles).

Thomas and Camille checking the contents of the aerial malaise trap

It was an amazing day for natural history.  In fact, I sometimes think my graduate students cannot stand spending time in the field with me, since I tend to walk slowly, vial in hand, stopping all the time to pick up a spider or beetle, or to turn over a log to search for pseudoscorpions.    I’m probably much more of a burden than a help in the field, and this probably leads to some resentment (ha ha).

Anyway – it was great to get into the forest again after time in the Arctic, and I was thrilled at all the biodiversity starting me in the face.

What did I see?

A dozen or more species of trees, including shagbark hickory, ironwood, and the usual suspects (American beech, sugar maple, red maple, some oaks)

Some stunning underwing moths (Catocala) (although they were somewhat less stunning than usual since they were dead, in a Lindgren funnel!)

The BIGGEST horsefly that I have ever seen (probably Tabanus atratus).  Yikes – I captured it before it bit me – it could have hurt.  A lot.

The big, nasty horse fly (Tabanidae)

Butterflies, butterflies, butterflies!  Including the beautiful great spangled fritillary (Speyeria cybele) and the northern pearly-eyed (Enodia anthedon)- the latter is one of the few shade-loving butterflies in this part of the world

Hundreds of sap beetles (family Nitidulidae) – these were very common in the aerial malaise traps, but were also flying into us much of the day

Some GIANT Scarabaeidae beetles – I don’t know the species but they were robust and impressive; masters of their universe.

Dozens of Harvestmen (Opiliones), which I later identified as Leiobunum aldrichi – I have now started a colony at home (much to my children’s delight).

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

Gypsy moth (Lymantria dispar) – a lot of gypsy moth.  This species in an invasive, introduced species.  Gypsy moth caterpillars can feed on hundreds of species of trees, including our beloved Sugar maple.  This is one species that I am not happy about seeing, and its numbers this year are certainly higher than last year.

And to top it all off.. Antlions (Neuroptera: Myrmeleontidae).  Yes, Antlions!!  These are among the most fascinating of the insects -the larvae build conical sand-pits and await ants that happen to slip into the pit and fall down into the waiting predator.  I have lived in the Montreal area for over 10 years and I had no idea that Antlions existed this far north.  Wow.

Quebec Antlion “trap”, photographed just south of Montreal

This is only part of the list, but one thing is clear – a hot, mid-summer day in a Montreal-area forest is full of the wonders of Nature.  I didn’t have to look very far, and I didn’t have to look very hard.  Furthermore, most of what I mentioned was all from a rather small forest fragment surrounded by agricultural lands.   We must study, document, quantify the biodiversity within these forest fragments – they are very special, and they host a diverse and fascinating flora and fauna.

 Take a walk in your local woods, and see what you can find under leaves, bark, climbing up trees and catching a few rays of sun in a small clearing.  It’s a nice way to spend a summer day.

Daddy longlegs: spider or harvestmen?

I’m about half-way through the “Opiliones Project” – this is a twitter-project devoted to sharing facts about Harvestmen (follow using the hashtag #OpilionesProject).  As I was working through some of the chapters, I gave a lot of attention to the variety of common names given to Harvestmen, including Daddy Longlegs.  This is not a very good common name for Opiliones because the characteristic of ‘long legs’ is not common to all Harvestmen, and many species (especially in tropical regions) are rather stout and don’t have the long, dangly, legs that we often associate with Opiliones in more northern regions.

The other reason to avoid the name daddy longlegs for Harvestmen is because of the confusion it creates with respect to a distant relative of Harvestmen – a spider with the latin name of Pholcus phalangioides.  This species is often referred to as the “Daddy longlegs spider” (and, by the way, the name “Phalangida” has historically been used as a synonym to Opiliones – more confusion!).   The rather obvious similarity between northern Harvestmen and Pholcus phalangioides is that they both have long legs – but it stops there.  Spiders have a narrow waist (i.e., the constriction between the cephalothorax and abdomen) whereas Harvestmen do not.  Pholcus phalangioides is also an enthusiastic web-builder whereas Harvestmen do not live in webs.  Here’s a photo of Pholcus phalangioides, courtesy of Ashley Bradford. (thanks, Ashley, for permission to use your photograph!)

A cellar spider, with prey (c) A. Bradford

Comparing a Spider to a Harvestmen is like comparing a blue whale to a chimpanzee.  Spiders are a different order (Araneae) than Harvestmen (Opiliones), and although both Arachnids, they diverged millions of years ago.  Opiliones are more closely related to Scorpions, Pseudoscorpions, and Solifugids than they are to the Araneae.

The other common name for Pholcus phalangioides is the “cellar spider” and this is much more appropriate – these spiders are synanthropic (see my other posts about spiders that like living in or near your home, the zebra spider & the ceiling spider), and are very commonly found in dark, damp places in and around human structures.  In my own house, the garage and basement are the common habitats.   Pholcus phalangioides is very distinctive – in addition to its long legs, it is a fascinating species from a behavioural perspective – if disturbed, it gyrates and whirls around in an impressive display of arachno-energy.  This is something I encourage you to try with your own populations of the species – it is wonderful to watch.  This behaviour is very well documented on youtube.  For example….

Wikipedia has an interesting entry about Pholcus phalangioides – including mention that one of its other common name is the “skull spider” because of patterning on its abdomen.  I also learned that the television show “Mythbusters” did an episode (in 2004) devoted to this species!   They busted the myth that this species had potent venom, but was unable to to pierce human skin (you can watch some of that episode here).

There has been some high quality research done on Pholcus phalangioides.  A nice overview of the biology of the species was provided by Jackson & Brassington, in 1987 – their paper is a key source for taking you back to the older literature on the species, and they also provide evidence that Pholcus phalangioides is an aggressive mimic of other spiders, and they are araneophagous (i.e., eat other spiders).  More recently,  Schafer and Uhl, in 2002, focused on mating behaviour and the role of male “pedipalp movements” as predictors of paternity in the species.  Bernhard Huber has recently (2011) written about the phylogeny and classification of the family Pholcidae and provided an updated cladistic analysis.

Keep an eye out for these characteristic spiders and don’t confuse them with the Opiliones…and be careful using the common name of Daddy Longlegs – it means different things to different people.

References:

Jackson, R.R. & R.J. Brassington. 1987.  The Biology of Pholcus phalangioides – predatory versatility, araneophagy and aggressive mimicry.  J. Zool. 211: 227-238. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1987.tb01531.x/abstract

Huber, B. (2011). Phylogeny and classification of Pholcidae (Araneae): an update Journal of Arachnology, 39 (2), 211-222 DOI: 10.1636/CA10-57.1

Schäfer, M., & Uhl, G. (2002). Determinants of paternity success in the spider Pholcus phalangioides (Pholcidae: Araneae): the role of male and female mating behaviour Behavioral Ecology and Sociobiology, 51 (4), 368-377 DOI: 10.1007/s00265-001-0448-9

Learn about Harvestmen: The Opiliones Project


Promitobates species. Photo (c) Techuser, with permission

Daddy longlegs, Shepherd spiders, Harvestmen, Grandfather greybeard.  These are just some of the common names for the Arachnid Order Opiliones (formerly Phalangida).  Although there are over 6,000 described Opiliones species, they remain relatively poorly known.  That is until a few years ago…  In 2007, Ricardo Pinto-da-Rocha, Glauco Machado and Gonzalo Giribet published “Harvestmen: The Biology of Opiliones“.  This tome comes in at just over 600 pages, and it is a magnificent achievement.  The book assembles and synthesizes a wealth of information on Harvestmen, including their cultural and historical importance, functional anatomy, reproductive behaviour, biogeography, taxonomy and systematics, and more.

Harvestmen textbook cover.

I have been quite fascinated by Opiliones for a long time, and find myself drawn to their awkward gait, and their unusual biology.  I am also always keen to learn more about all kinds of Arachnids, and I am embarrassed that I don’t know how to identify these lovely animals.    For these reasons, I purchased the aforementioned book, and started reading it.  I must be honest, it’s a very expensive book making in hard to justify for the “casual biologist” and I am privileged to be able to afford it.  It’s also very dense, and although information rich, is not entirely accessible to non-arachnophiles.

I am on a continual crusade to share knowledge about Arachnids with anyone who will listen.  And, like spiders, there is a lot of misinformation out there about Opiliones.  I want to invite you into the wonderful world of Opiliones, and I will do this by sharing small snippets of this textbook with you.  I’ll call this endeavour “The Opiliones Project” and my goal will be to bring you along to learn some interesting facts about the Opiliones as I wade through the different Chapters.   This is not an entirely altruistic process, as by committing this to you, it also gives me incentive to read carefully, and with an eye for detail (something I don’t typically have time to do!).

A few ground rules:

1) To take part, you need a Twitter account and an Internet connection.

2) This project is open to ANYONE with an interest in Arachnids

3) This will be a slow process, and will likely take several months.

4) I will paraphrase details from the textbook, and unless indicated otherwise, the ‘citation’ for this project will be: Pinto-da-Rocha et al. (2007) Harvestmen: The Biology of Opiliones. Harvard Univ. Press.  You can, therefore, fact-check by looking at the book, and I will welcome this opportunity (oh, and in case you are wondering, Ricardo Pinto-da-Rocha is 100% supportive of this project).  Now and then I will also try to bring other primarily literature to the discussion.

Interested?  if so…. please follow this project on twitter using the hashtag #OpilionesProject (I will tweet from my account @CMBuddle) – and please join in the discussion using that hashtag – the more interaction, the better.

Once finished, I will assemble all the tweets on storify.

This should be fun.  It’ll be an interactive, and hopefully engaging way for all of us to learn more about some incredible Arachnids.  If you are not yet convinced, just look at this (thanks to Joe Warfel, EigthEyePhotography for permission to use this photo):

A tiny Opiliones, genus Caddo - it can be found in north-temperate regions (C) J. Warfel