On Friday, while walking to work I found this male wasp, cold and still on the pavement. This was a male western yellowjacket, Vespula pensylvanica, and he was in rough shape. Even here in Vancouver, wintry weather comes this time of year, and we have had freezing nights for almost a week.
Males are easy to recognize, as they have long, 13 segmented antennae, and a long gaster with 7 apparent segments. Females have 6 segments on the gaster, and 12-segmented antennae.
With the freezing weather we have had, this male was not really able to fly, so he was cooperative for some photos.
I have seen male yellowjackets later in the year than this, usually when their nest is within a heated home.
Further south, western yellowjackets have year-round colonies, with multiple queens, but here in Canada they generally conform to the single-foundress colony mode, with a single queen starting a colony in the spring, and dying off in the winter after producing males and new queens.
After this session, I found a nice sunstruck patch of moss, and laid down some honey (which I keep in a vial for ant photography) and let him have a last meal in the sun before the cold of night came to end his life.
https://esc-sec.ca/wp-content/uploads/2016/12/5th_annual_36.jpg469656Sean McCannhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngSean McCann2014-11-16 10:45:252019-11-14 21:30:20The last of the yellowjackets?
The following is a guest post by Terry Wheeler, from the Lyman Entomological Museum at McGill University. It is re-posted from the Lyman Museum Blog, where it originally appeared.
Two wolf spiders, whose names are Pardosa lapponica and Pardosa concinna, run across open ground all over northern Canada. Here’s the problem: these two species of spiders live in a lot of the same places, and they look very similar. Katie Sim, a grad student working with Chris Buddle and me here at McGill, asked the obvious question: are these spiders really separate species? Katie’s insights on that question were just published in the journal Zootaxa.
As taxonomists, we can use multiple kinds of evidence to determine species limits. This includes things like morphology, genetic sequence data, geographic distribution, and ecology. These two species were originally described from widely separated areas: P. lapponica from Lapland, and P. concinna from Colorado. But since then they’ve been found in many more sites and we now know that their ranges overlap in northern North America.
The other long-accepted way of distinguishing between these two species was a small morphological difference between their reproductive structures (many closely related arthropods look very similar externally, but if there are differences, we often see them in the genitalia. “Why?” is a topic for another post).
As Katie collected spiders as part of our Northern Biodiversity Program fieldwork in northern Canada, she realized that the morphological differences between the two species weren’t that clear-cut, once you take variation into account. Based on careful measurements of specimens from all across the north, Katie found overlap in almost all morphological characters, even genitalic characters that had been used in the past. There was only one small piece of the complex male mating structures (the terminal apophysis, for the spider fans reading along) that seemed to hold up as a difference between the species (and only the males, obviously). Question marks started to appear.
Katie’s next step was to delve into the genetic differences between the two species. Even though species can look very similar externally, DNA sequence data sometimes uncovers fine differences between them. This is especially helpful with closely related, or recently diverged species. Katie used the DNA barcode, a section of the mitochondrial gene CO1, which has proven pretty useful for distinguishing animal species. And the DNA results showed some interesting patterns, some of which were unexpected.
The figure above is a haplotype network. Each circle is a little island of genetic similarity, connected to other islands by the lines. We’d expect different species to be part of separate “islands”, but that didn’t happen here. Pardosa lapponica (in light gray) and P. concinna(in black) sometimes share the same haplotype, and each of the two has multiple haplotypes. That means there’s more genetic variation within a “species” than between them. But wait! There’s more!
After a suggestion from one of the reviewers on an earlier version of the paper (this back-and-forth of suggestions is one of the strengths of peer-reviewed science), Katie looked at the CO1 barcode sequences of P. lapponica specimens from northern Europe, where it was originally described. Unexpectedly, the Russian specimens (the dark gray circles without numbers in the figure above) were genetically distinct, by a good margin, from the North American specimens of P. lapponica.
So what does this all mean, taxonomically? First, the spider we call “Pardosa lapponica” in North America seems not to be the same species as “Pardosa lapponica” from northern Europe (which “owns” the name, because it was described from there first). Our North American P. lapponica may, in fact, be the same species as the spider we’ve been callingPardosa concinna, but before we can make the final decision on that, it would be necessary to study additional North American specimens, especially from Colorado (the “type locality”, or collection site of the original P. concinna), to confirm this.
And that’s how taxonomy often works: good, careful research will answer one question, and in the process, new questions pop up. Sometimes, you think you know a spider, and sometimes, you realize you really don’t.
https://esc-sec.ca/wp-content/uploads/2016/12/5th_annual_28.jpg469335Sean McCannhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngSean McCann2014-11-13 06:00:152019-11-14 21:30:17Spiders with an identity crisis: a new taxonomy paper
The following is a guest post from ESC student member Sharleen Balogh. Sharleen is a Masters student at the University of Northern British Columbia (UNBC) working with Dezene Huber and Staffan Lindgren on Warren Root Collar Weevils. She recently took home a President’s Prize for best talk at the ESC/ESS JAM in Saskatoon.
For the past two years, I have been studying the Warren root collar weevil (Hylobius warreni). These weevils are fairly large and long-‐lived (for insects anyways, they are about 12-‐15 mm, and live for up to five years). I think they are big enough to have distinct faces and personalities, although some people have told me that I’m personifying them just a bit too much and I need to take a step back from my work, but that’s another story altogether.
I am studying them because of their effects on coniferous trees, especially young lodgepole pines regenerating after the mountain pine beetle infestation in the interior of British Columbia. The larvae feed on the roots and root collars of trees, causing mortality of young trees and growth reductions in older trees (Cerezke 1994). They are native to the Prince George area (where I am doing my research) and can be found across much of Canada. They are often fairly common within their range. However they really can be described as “everywhere and nowhere”, since you can find them in almost any forested area in the region, just in low numbers and often well-‐hidden.
The Warren root collar weevil. How can you not love that face? Photo: Staffan Lindgren
I have specifically been looking at the mechanisms by which they locate their host trees. The weevils can’t fly, so they walk along the ground in search of hosts. We know that they use vision (Machial et al. 2012a) to locate trees, but not much else about their host location. There are higher rates of attack by larvae on larger trees, but this could just be a result of a larger area of roots available, not an actual preference when finding hosts. So far no one has been able to find any chemical cues that they use, although this is very unusual for an insect. Some evidence suggests that at least in some situations their movements may be predominantly random and non-‐directional (Machial et al. 2012b, Klingenberg et al. 2010).
In order to study them, I decided to track the weevils using harmonic radar technology. This is the same technology that is used to locate avalanche victims. It functions by the detector sending out a signal in the microwave range that is passively reflected back by a transponder, attached to whatever you want to find. For use in locating avalanche victims, the transponder is the large Recco® tags you often see in ski jackets. In the case of the weevils, I used a miniaturized transponder– a tiny diode soldered to a 4 cm long piece of copper wire.
When I first decided to use this method, and to construct the transponders myself, I went online to learn how to solder. I was told by several different tutorials that it is “very easy, almost impossible to get wrong”. This may be the case when soldering computer circuit boards, but not so when soldering two tiny pieces of metal together under the microscope. In the end though, I did get it to work, and I tagged 115 weevils over two field seasons. I released them into individual plots in a lodgepole pine stand, within which I had mapped all of the trees, and I relocated them at regular intervals.
Although I’m still analyzing my data, my results suggest that the weevils preferred to go to closer trees, larger trees, and that the preference for larger trees increases when the trees are further away. Otherwise, their movements appear to be primarily random and non-‐directional. So, as strange as it is, maybe they do just use vision and random movements. If this is true, and their host selection process is predominantly random, this may have implications for forest management. It might make finding ways to limit their spread into new stands difficult, and it may make it difficult or impossible to identify potential genetically resistant trees for planting.
Warren root collar weevil tagged with transponder. Photo: Staffan Lindgren
The following post is by Chloe Gerak, a Masters student at UBC who completed an undergraduate project at Simon Fraser University in the Gries lab.This past weekend, she won the top prize for an undergraduate talk at the Annual General Meeting of the Entomological Society of British Columbia with a talk entitled “How the false widow finds true love”. Photos by Sean McCann.
A male Steatoda grossa. These spiders have stereotyped courtship behaviour involving stridulation of an organ located dorsally between the cephalothorax and abdomen.
For approximately eight months, I studied the courtship behaviour and chemical communication between male and female false widow spiders, Steatoda grossa. Prior to studying them in Prof. Gerhard Gries’ lab at Simon Fraser University, I had never even heard of this species!
Female Steatoda grossa on her web.
My mentor Catherine Scott and I had collected juvenile and mature false widow spiders around the basement of the biology wing at SFU… and let’s just say we didn’t have a lack of specimens to collect. Almost every baseboard we turned over or corner we searched, we would find these little guys and collect them individually into petri dishes. These formed the nucleus of our laboratory colony which we reared for behavioural experiments.
A common nickname for Steatoda grossa is the “cupboard spider,” which I find extremely appropriate considering these spiders seem to love dwelling in dark corners. Since they are so abundant around SFU, and I had never even seen one before this, I think people should not be frightened by cohabiting with them… likely, you won’t even know they are there!
https://esc-sec.ca/wp-content/uploads/2016/12/5th_annual_11.jpg7501000Sean McCannhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngSean McCann2014-10-29 05:00:142019-11-14 21:30:13Exotic field collecting…in the hallway!
The following post comes to us from our new President, Staffan Lindgren, who in addition to being a great researcher, takes the time to make natural history observations which are crucial for any entomologist.
On occasion I grab my camera and go out in the garden to see if some photogenic insect or other arthropod is willing to pose for me. On October 18, I went out to see what was happening around the rose bushes between ours and our neighbour’s yard. I was immediately struck by the fairly intense activity of yellowjackets, which peaked my curiosity. After looking around for a while I saw what the commotion was all about; a large queen was being mobbed by a number of males. To my knowledge, I have never seen a male yellowjacket wasp before. A casual observer would just think that they were workers, since they are about the same size and don’t otherwise look obviously different. Looking closer I realized that the queen was in copula with one of the males, so I tried to get some photos. It immediately became clear that I had the wrong lens on; my Canon MP-E 65 macro simply couldn’t capture the entire scene. Therefore the photos I managed to take only show parts of the scene. I didn’t have time to go back and change the lens, unfortunately, but below are a few shots.
Here is another view of the male.
This is the queen. The male she was mating with is in the lower right corner. Note the second male trying to mate with her in the background. Note also that her legs are not in contact with the leaf; she was essentially held by the male.
And here is a view of the act of mating, showing the male in the foreground holding on to the queen. Using these photos and the identification guide to the Vespinae I came to the conclusion that these are Vespula pensylvanica Saussure.
https://esc-sec.ca/wp-content/uploads/2016/12/5th_annual_4.jpg800534Sean McCannhttp://esc-sec.ca/wp/wp-content/uploads/2017/01/ESC_logo-300x352.pngSean McCann2014-10-26 03:00:552019-11-14 21:30:10Mating of western yellowjackets
The last of the yellowjackets?
On Friday, while walking to work I found this male wasp, cold and still on the pavement. This was a male western yellowjacket, Vespula pensylvanica, and he was in rough shape. Even here in Vancouver, wintry weather comes this time of year, and we have had freezing nights for almost a week.
Males are easy to recognize, as they have long, 13 segmented antennae, and a long gaster with 7 apparent segments. Females have 6 segments on the gaster, and 12-segmented antennae.
With the freezing weather we have had, this male was not really able to fly, so he was cooperative for some photos.
I have seen male yellowjackets later in the year than this, usually when their nest is within a heated home.
Further south, western yellowjackets have year-round colonies, with multiple queens, but here in Canada they generally conform to the single-foundress colony mode, with a single queen starting a colony in the spring, and dying off in the winter after producing males and new queens.
After this session, I found a nice sunstruck patch of moss, and laid down some honey (which I keep in a vial for ant photography) and let him have a last meal in the sun before the cold of night came to end his life.
Spiders with an identity crisis: a new taxonomy paper
The following is a guest post by Terry Wheeler, from the Lyman Entomological Museum at McGill University. It is re-posted from the Lyman Museum Blog, where it originally appeared.
Two wolf spiders, whose names are Pardosa lapponica and Pardosa concinna, run across open ground all over northern Canada. Here’s the problem: these two species of spiders live in a lot of the same places, and they look very similar. Katie Sim, a grad student working with Chris Buddle and me here at McGill, asked the obvious question: are these spiders really separate species? Katie’s insights on that question were just published in the journal Zootaxa.
As taxonomists, we can use multiple kinds of evidence to determine species limits. This includes things like morphology, genetic sequence data, geographic distribution, and ecology. These two species were originally described from widely separated areas: P. lapponica from Lapland, and P. concinna from Colorado. But since then they’ve been found in many more sites and we now know that their ranges overlap in northern North America.
The other long-accepted way of distinguishing between these two species was a small morphological difference between their reproductive structures (many closely related arthropods look very similar externally, but if there are differences, we often see them in the genitalia. “Why?” is a topic for another post).
As Katie collected spiders as part of our Northern Biodiversity Program fieldwork in northern Canada, she realized that the morphological differences between the two species weren’t that clear-cut, once you take variation into account. Based on careful measurements of specimens from all across the north, Katie found overlap in almost all morphological characters, even genitalic characters that had been used in the past. There was only one small piece of the complex male mating structures (the terminal apophysis, for the spider fans reading along) that seemed to hold up as a difference between the species (and only the males, obviously). Question marks started to appear.
Katie’s next step was to delve into the genetic differences between the two species. Even though species can look very similar externally, DNA sequence data sometimes uncovers fine differences between them. This is especially helpful with closely related, or recently diverged species. Katie used the DNA barcode, a section of the mitochondrial gene CO1, which has proven pretty useful for distinguishing animal species. And the DNA results showed some interesting patterns, some of which were unexpected.
The figure above is a haplotype network. Each circle is a little island of genetic similarity, connected to other islands by the lines. We’d expect different species to be part of separate “islands”, but that didn’t happen here. Pardosa lapponica (in light gray) and P. concinna(in black) sometimes share the same haplotype, and each of the two has multiple haplotypes. That means there’s more genetic variation within a “species” than between them. But wait! There’s more!
After a suggestion from one of the reviewers on an earlier version of the paper (this back-and-forth of suggestions is one of the strengths of peer-reviewed science), Katie looked at the CO1 barcode sequences of P. lapponica specimens from northern Europe, where it was originally described. Unexpectedly, the Russian specimens (the dark gray circles without numbers in the figure above) were genetically distinct, by a good margin, from the North American specimens of P. lapponica.
So what does this all mean, taxonomically? First, the spider we call “Pardosa lapponica” in North America seems not to be the same species as “Pardosa lapponica” from northern Europe (which “owns” the name, because it was described from there first). Our North American P. lapponica may, in fact, be the same species as the spider we’ve been callingPardosa concinna, but before we can make the final decision on that, it would be necessary to study additional North American specimens, especially from Colorado (the “type locality”, or collection site of the original P. concinna), to confirm this.
And that’s how taxonomy often works: good, careful research will answer one question, and in the process, new questions pop up. Sometimes, you think you know a spider, and sometimes, you realize you really don’t.
Reference
Sim, K.A., C.M. Buddle, and T.A. Wheeler. 2014. Species boundaries of Pardosa concinna and P. lapponica (Araneae: Lycosidae) in the northern Nearctic: morphology and DNA barcodes. Zootaxa: 3884: 169–178.
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Tracking the Warren Root Collar Weevil
The following is a guest post from ESC student member Sharleen Balogh. Sharleen is a Masters student at the University of Northern British Columbia (UNBC) working with Dezene Huber and Staffan Lindgren on Warren Root Collar Weevils. She recently took home a President’s Prize for best talk at the ESC/ESS JAM in Saskatoon.
For the past two years, I have been studying the Warren root collar weevil (Hylobius warreni). These weevils are fairly large and long-‐lived (for insects anyways, they are about 12-‐15 mm, and live for up to five years). I think they are big enough to have distinct faces and personalities, although some people have told me that I’m personifying them just a bit too much and I need to take a step back from my work, but that’s another story altogether.
I am studying them because of their effects on coniferous trees, especially young lodgepole pines regenerating after the mountain pine beetle infestation in the interior of British Columbia. The larvae feed on the roots and root collars of trees, causing mortality of young trees and growth reductions in older trees (Cerezke 1994). They are native to the Prince George area (where I am doing my research) and can be found across much of Canada. They are often fairly common within their range. However they really can be described as “everywhere and nowhere”, since you can find them in almost any forested area in the region, just in low numbers and often well-‐hidden.
The Warren root collar weevil. How can you not love that face? Photo: Staffan Lindgren
I have specifically been looking at the mechanisms by which they locate their host trees. The weevils can’t fly, so they walk along the ground in search of hosts. We know that they use vision (Machial et al. 2012a) to locate trees, but not much else about their host location. There are higher rates of attack by larvae on larger trees, but this could just be a result of a larger area of roots available, not an actual preference when finding hosts. So far no one has been able to find any chemical cues that they use, although this is very unusual for an insect. Some evidence suggests that at least in some situations their movements may be predominantly random and non-‐directional (Machial et al. 2012b, Klingenberg et al. 2010).
In order to study them, I decided to track the weevils using harmonic radar technology. This is the same technology that is used to locate avalanche victims. It functions by the detector sending out a signal in the microwave range that is passively reflected back by a transponder, attached to whatever you want to find. For use in locating avalanche victims, the transponder is the large Recco® tags you often see in ski jackets. In the case of the weevils, I used a miniaturized transponder– a tiny diode soldered to a 4 cm long piece of copper wire.
When I first decided to use this method, and to construct the transponders myself, I went online to learn how to solder. I was told by several different tutorials that it is “very easy, almost impossible to get wrong”. This may be the case when soldering computer circuit boards, but not so when soldering two tiny pieces of metal together under the microscope. In the end though, I did get it to work, and I tagged 115 weevils over two field seasons. I released them into individual plots in a lodgepole pine stand, within which I had mapped all of the trees, and I relocated them at regular intervals.
Although I’m still analyzing my data, my results suggest that the weevils preferred to go to closer trees, larger trees, and that the preference for larger trees increases when the trees are further away. Otherwise, their movements appear to be primarily random and non-‐directional. So, as strange as it is, maybe they do just use vision and random movements. If this is true, and their host selection process is predominantly random, this may have implications for forest management. It might make finding ways to limit their spread into new stands difficult, and it may make it difficult or impossible to identify potential genetically resistant trees for planting.
Warren root collar weevil tagged with transponder. Photo: Staffan Lindgren
References Cited:
Cerezke, H.F. 1994. Warren rootcollar weevil, Hylobius warreni Wood (Coleoptera: Curculionidae), in Canada: ecology, behavior, damage, relationships, and management. The Canadian Entomologist. 126: 1383-‐1442
Machial, L.A., B.S. Lindgren, and B.H. Aukema. 2012a. The role of vision in the host orientation behaviour of Hylobius warreni. Agricultural and Forest Entomology. 14:
286-‐294
Machial, L.A., B.S. Lindgren, R.W. Steenweg, and B.H. Aukema. 2012b. Dispersal of Warren root collar weevils (Coleoptera: Curculionidae) in three types of habitat. Environmental Entomology. 41: 578-‐586
Klingenberg, M.D., N. Bjorklund, and B.H. Aukema. 2010. Seeing the forest through the trees: differential dispersal of Hylobius warreni within modified forest habitats. Environmental Entomology. 39: 898-‐906
Exotic field collecting…in the hallway!
The following post is by Chloe Gerak, a Masters student at UBC who completed an undergraduate project at Simon Fraser University in the Gries lab.This past weekend, she won the top prize for an undergraduate talk at the Annual General Meeting of the Entomological Society of British Columbia with a talk entitled “How the false widow finds true love”. Photos by Sean McCann.
A male Steatoda grossa. These spiders have stereotyped courtship behaviour involving stridulation of an organ located dorsally between the cephalothorax and abdomen.
For approximately eight months, I studied the courtship behaviour and chemical communication between male and female false widow spiders, Steatoda grossa. Prior to studying them in Prof. Gerhard Gries’ lab at Simon Fraser University, I had never even heard of this species!
Female Steatoda grossa on her web.
My mentor Catherine Scott and I had collected juvenile and mature false widow spiders around the basement of the biology wing at SFU… and let’s just say we didn’t have a lack of specimens to collect. Almost every baseboard we turned over or corner we searched, we would find these little guys and collect them individually into petri dishes. These formed the nucleus of our laboratory colony which we reared for behavioural experiments.
A common nickname for Steatoda grossa is the “cupboard spider,” which I find extremely appropriate considering these spiders seem to love dwelling in dark corners. Since they are so abundant around SFU, and I had never even seen one before this, I think people should not be frightened by cohabiting with them… likely, you won’t even know they are there!
Mating of western yellowjackets
The following post comes to us from our new President, Staffan Lindgren, who in addition to being a great researcher, takes the time to make natural history observations which are crucial for any entomologist.
Male Vespula pensylvanica. This was the male that was mating with the queen.
On occasion I grab my camera and go out in the garden to see if some photogenic insect or other arthropod is willing to pose for me. On October 18, I went out to see what was happening around the rose bushes between ours and our neighbour’s yard. I was immediately struck by the fairly intense activity of yellowjackets, which peaked my curiosity. After looking around for a while I saw what the commotion was all about; a large queen was being mobbed by a number of males. To my knowledge, I have never seen a male yellowjacket wasp before. A casual observer would just think that they were workers, since they are about the same size and don’t otherwise look obviously different. Looking closer I realized that the queen was in copula with one of the males, so I tried to get some photos. It immediately became clear that I had the wrong lens on; my Canon MP-E 65 macro simply couldn’t capture the entire scene. Therefore the photos I managed to take only show parts of the scene. I didn’t have time to go back and change the lens, unfortunately, but below are a few shots.
Here is another view of the male.
This is the queen. The male she was mating with is in the lower right corner. Note the second male trying to mate with her in the background. Note also that her legs are not in contact with the leaf; she was essentially held by the male.
And here is a view of the act of mating, showing the male in the foreground holding on to the queen. Using these photos and the identification guide to the Vespinae I came to the conclusion that these are Vespula pensylvanica Saussure.