Nouvelles
If you are a fan of Canadian neuropteroids, your bucket list should include a trip out west to see one of our best selling points: the Raphidioptera, or snakeflies. The most common of these are in the genus Agulla, and this morning I found several female Agulla when out for a walk at Mt. Tolmie in Victoria.
The way the pronotum curls around the anterior of the elongated thorax like a little jacket is strangely pleasing.
Snakeflies have a fully motile pupal stage, something I found out just the other day, finding this pupa in a decaying branch of Garry Oak.
Here is a freshly-emerged snakefly I found in Oregon a few weeks ago. Note how the wings appear milky and the antennae are not fully hardened.
I had hoped to catch these against a blazing orange dawn, but like so many dawns on the west coast, today was rather cloudy.
Against the mossy bedrock of the Garry Oak meadow, the female snakefly blends in quite well.
One of the most surprising things I have learned about snakeflies over the years is that the larvae have a very effective reverse locomotion that allows them to quickly back away from danger. Check it out:
[youtube https://www.youtube.com/watch?v=vGkoaRd4_fc&w=640&h=480]
So if you are ever on the west coast at this time of year, please look for these awesome creatures. You will be glad you did.
Staffan with Graduate student Jeanne Robert, 2005. Jeanne went on to do a PhD at UBC, then came back to UNBC, where she worked as a post-doctoral fellow and then a Research coordinator for the UNBC NRESi Biodiversity Monitoring & Assessment Program. She is now the Regional Entomologist, Northern Region, for the BC Ministry of Forest, Lands and Natural Resources Operations, Prince George, BC. I was lucky to have a great graduate student. Was she lucky? Only through hard work!
The following is a guest post by Staffan Lindgren
When I was about 10 years old I won a competition in a hobby magazine, which landed me a nice race car track. Since then I have not won anything, really. Yet, I consider myself a lucky person, not only because of a great family life, but because opportunities have always seemed to pop up just when I needed them. But looking back, I would say that my luck was in large part self-made. Over the years, I had made sure I had summer and temporary jobs that gave me appropriate experience, e.g., as a substitute teacher, forest regeneration surveyor, etc.
When I was doing my undergraduate degree in Sweden, the course offerings in the fall of 1973 were not to my liking, so I landed a job as a research assistant to a PhD student studying spiders. But the reason I did, was that I had a longstanding interest in spiders, so I had connected with the student long before that. For example, as a 12-year-old, I wrote to Professor Åke Holm, Uppsala University, after reading a newspaper article posted on a board in my English teachers classroom. Dr. Holm was then Sweden’s pre-eminent spider taxonomist, and had published my first spider book (Holm 1947). His kindness and encouragement has served as a model for me throughout my career. After I graduated with my undergraduate degree, I made a misguided attempt at a PhD in medical endocrinology, studying testosterone secretion in rats. Apart from five small publications (Carstensen et al. 1976, Lindgren et al. 1976, Damber et al. 1977a, Damber et al. 1977b, Bergh et al. 1982), I came away with a bruised ego and a severe allergy to rats.
After my failed 2-year forage into mammal reproductive physiology, I realized that I needed to re-focus on my first love, which was entomology. The first thing I did was to contact (by which I mean that I wrote a letter ) Dr. Bertil Lekander, professor of forest entomology at the Royal College of Forestry, Stockholm, Sweden. He offered to take me on as a special interest student in the two forest entomology courses offered to future foresters. To make a long story short, this led to a life-long association, albeit informal, with Swedish forest entomologists. For example, I published my Master of Pest Management Professional Paper as a Forest Entomology report (which also has a long story associated with it, the main lesson of which is the old adage “It’s not what you say, but how you say it”), and I had the privilege of spending 6 months as a visiting scientist at SLU in Uppsala in 1993 thanks to the connections I made there. Nevertheless, a few courses did not lead to a specific job, so once that was done I was once again without a firm direction in life. Because I had made many friends and connections in the Department of Ecological Zoology at Umeå University, in part through the spider job, but also through volunteering every spring and fall on an annual 4-day microtine rodent survey (Hörnfeldt et al. 1986) I got wind of a 4-month Teaching Assistant position in the Department of Health and Environment, which I was offered (notably in competition with another future entomologist, Anders N. Nilsson, who became a world authority on aquatic beetles). This position involved leading a class trip to the Soviet Union, among other things.
Staffan with a nice rainbow trout from Wicheeda Lake, north of Prince George. Now this may have been luck, because I don’t work hard at my fishing skill!
At the end of that position, I had started the proceedings to go to Canada, which ultimately led me to where I am today. Again, this was not something that happened by accident. In 1968-69, I spent a year in central Michigan as a high school exchange student. This was an extremely formative experience for me. It made me confident that I could succeed in an English-speaking environment, and it shaped me politically (it was the height of the Vietnam War, two political assassinations , Martin Luther King, Jr. and Robert F. Kennedy, Jr., had happened earlier in 1968), and there were significant racial tensions throughout the US. Anyway, I had become convinced that applied science was the only worthwhile pursuit in terms of education (see my earlier post here), and had found the Centre for Overseas Pest Research, a British organization. (Remember that there was no Google or internet, so all of this was done through libraries and by asking for information by mail). I received a letter back that they could only offer employment to “British subjects”, but they passed on a brochure about the Master of Pest Management program at Simon Fraser University. This seemed like the ticket to my future, so I wrote to SFU. The response was positive, so I decided to apply. But I needed funding. Fortunately for me, I managed to land a fellowship from the Sweden-America Foundation, and in combination with the relatively generous student loans from the Swedish Government, I all of a sudden found myself in a position to go to Canada! And the rest is history, as they say!
What does this history of my formative years have to do with luck? I truly believe that some people have more luck than others. When you buy a lottery ticket, the odds are fixed. But in the job market, including academia, you can change the odds in your favour, at least to some degree. The points I take home from the experience I have accumulated over my career are:
- If people know you, they will pass on information that may lead to your big break.
- Treat people with respect, i.e., treat them the way you wish to be treated. If you are well liked and respected, it will make a difference when you are looking for references or recommendations. This is particularly important when dealing with workers. I found that by showing an interest in, and respect for, their experience and knowledge rather than acting superior, you gain their trust and respect, and they will welcome your opinion.
- Don’t hesitate to seek help or advice from professors, no matter how eminent or important they are. In entomology in particular, I have been amazed at the kindness and generosity I have encountered from people really had nothing to gain by responding or talking to me. The worst that can happen is that you don’t get a response, or one that makes you steer clear of that individual (which has yet to happen to me).
- We all have weaknesses. Work on them. I used to shake like a leaf when having to address an audience. Some of the best scientists and public speakers I know suffer from extreme nervousness, but they have learned to cope with it. If you suffer from nerve problems, seek help, or at least give yourself experience. There are tricks to help you, and you’d be amazed how experience helps!
- Never, ever pretend you know something you don’t. Honesty always pays off in my experience.
- Finally, and most importantly, follow your heart. If you are passionate about what you do, you are more likely (and able) to build experience, which in turn becomes as important, or more so, in a job interview.
These are some ways to “make you lucky”. Just like an athlete has to put time and effort into achieving their goals, we do as well.
Best of luck!
References
Bergh, A., J.-E. Damber, and S. Lindgren. 1982. Compensatory hypertrophy of the Leydig cells in hemiorchidectomized adult rats. Experientia 38:597-598.
Carstensen, H., S. Marklund, J.-E. Damber, B. Näsman, and S. Lindgren. 1976. No effect of oxygen in vivo on plasma or testis testosterone in rats and no induction of superoxide dismutase. Journal of Steroid Biochemistry 7:465-467.
Damber, J.-E., H. Carstensen, and S. Lindgren. 1977a. The effects of barbiturate anesthesia and laparotomy on testis and plasma testosterone in rats. J. Ster. Biochem. 8: 217-219.
Damber, J.-E., S. Lindgren, and B. Näsman. 1977b. Testicular blood flow and oxygen tension in unilaterally orchidectomized rats. Experientia 33:635.
Holm, Å. 1947. Svensk spindelfauna. 3, Egentliga spindlar. Araneae Fam. 8-10, Oxyopidae, Lycosidae och Pisauridae. Entomologiska Föreningen, Stockholm, Sweden.
Hörnfeldt, B., O. Löfgren, B.-G. Carlsson. 1986. Cycles in voles and small game in relation to variations in plant production indices in Northern Sweden. Oecologia (Berlin) 68:496–502
Lindgren, S., J.-E. Damber, and H. Carstensen. 1976. Compensatory testosterone secretion in unilaterally orchidectomized rats. Life Science 18:1203-1205.
Guest post by Staffan Lindgren (@bslindgren)
The other day I was practicing macro photography (I am still learning after several years of erratic success at best, so please excuse the imperfections) trying to patiently wait out some Halictus sweat bees with my camera. The bees appeared to be much more patient than I was, however, by which I mean that they sat deep in their burrows, apparently staring me down. So I wandered around looking for other potential subjects to practice on. While examining another bee burrow, I saw a slight movement in the dirt in a spot about 10 cm from the bee burrow. A closer look revealed a very attractive wolf spider hiding in a small depression. In spite of its gaudy colours (for a wolf spider) it was rather well camouflaged against the dirt. As I watched it, it started to move, and to my surprise picked up dirt and moved it to the edge of its little hiding spot. It remained in the depression and continued to modify it by moving dirt as I attempted to take some photographs. From what I could tell, it looked as if it used its pedipalps to hold the dirt against the base of its chelicerae to move it, rather than only grabbing it between the chelicerae.
I had no idea what species I was dealing with, so I went to the web to see if I could figure it out. It turned out to be Arctosa perita (Latreille, 1799), which confused me at first since it is a Eurasian species. A quick check of Bennett et al. (2014) confirmed its presence. I also found the post “The mystery of the burrow-dwelling sand dune spider” about this species on Catherine Scott’s informative blog “Spiderbytes”, as usual illustrated by a number of excellent photographs by Sean McCann. These sources confirmed that the spider occurs on Vancouver Island, and that it is a species known to make burrows.
These spiders have some pretty good camouflage, as well as subtle but beautiful colours. Photo by Sean McCann.
Apparently A. perita was introduced in southwestern BC at some point, and it has spread enough that it now seems fairly common, at least in the southwest corner of the province. In fact, we have numerous introduced species of insects and other arthropods in BC, particularly in urban and rural areas. For example, the most commonly seen ground beetles are generally invasives, although we tend to not think of them as such because they don’t impact us directly. They probably do impact the native fauna to some extent, however, albeit not noticeable to our selfserving views. After all, even earthworms (which are almost entirely non-native in Canada) have been labelled harmful to native fauna in forest environments, at least (Addison 2009). Whether or not A. perita has any noticeable effect on native fauna is unknown, but it is an interesting addition to our Canadian fauna.
References
Addison, J.A. 2009. Distribution and impacts of invasive earthworms in Canadian forest ecosystems. Biological Invasions. 11: 59-79.
Bennett, R., D. Blades, D. Buckle, C. Copley, D. Copley, C. Dondale, and R.C. West. 2014. Checklist of the spiders of British Columbia. (Web) http://ibis.geog.ubc.ca/biodiversity/efauna/documents/BCspiderlistMay2014FINAL.pdf
By B. Staffan Lindgren, Professor Emeritus
A while back, a paper accepted by The American Statistician entitled “The ASA’s statement on p-values: context, process, and purpose” was posted to the American Statistical Association website. The gist of the paper was that many disciplines rely too much on the p-value as the sole indicator of research importance. Not surprisingly, the paper received considerable attention.
Over my career, I had a love-hate relationship with statistics, knowing just enough to be dangerous, but not enough to really understand what I was doing. Consequently I relied on packaged software and/or colleagues or students who were more quantitatively minded than myself. For example, I generally made sure that a graduate student committee had at least one member with some strength in statistics to make sure I would not leave the candidate stranded or led astray. So if you read my thoughts below, keep in mind that I tread on very thin ice here. I fully expect some disagreement on this, but that is the way it is supposed to be. Ultimately it is your responsibility to understand what you are doing.
The approaches and tools for statistical analysis have changed a lot since my student days, which was at the dawn of mainframe computers for general use, on which we could use a software package called Textform rather than typing the thesis on a type writer as I (read “a secretary I hired and almost drove to depression”) did for my masters. My first visit to a statistical consultant at Simon Fraser University ended with the advice that “This data set can’t be analyzed, it contains zero values.” The software of choice was SPSS, which did not allow for any complexity, so I did a fair bit by hand (which might have been a good thing since it forced me to think about what I was doing, but certainly did not prevent errors). Later in my career it was sometimes a struggle to decide among differing opinions of statisticians what was and was not appropriate to use, but with a little help from my friends I think I managed to negotiate most of the pitfalls (no pun intended) fairly well.
The statistic-phobic author with his eponymous insect trap, preparing to gather data and test hypotheses. Photo: Ron Long.
One of the issues with our reliance on p-values is that it is tempting to do post-hoc “significance-hunting” by using a variety of approaches, rather than deciding a priori how to analyze the data. Data that show no significance often remains unpublished, leading to potential “publication bias”. In part this may be the result of journal policies (or reviewer bias), which tends to lead to rejection of papers reporting ‘negative’ results. We have also been trained to use an experiment-wise alpha of 0.05 or less, i.e., a significant result would be declared if the p-value is lower than 0.05. There are two problems with this. First, it is an arbitrary value in a sense, e.g., there really is no meaningful difference between p=0.049 and 0.051. Furthermore, the p-value does not really tell you anything about the importance of the result. All it can do is give some guidance regarding the interpretation of the results relative to the hypothesis. I have tried to make students put their research in context, because I believe the objective of the research may dictate whether or not a significant p-value is important or not. I used to work in industry, and one of the reasons I left was that recommendations I made based on research were not always acted upon. For example, pheromones of bark beetles are often synergized by various host volatiles. But whether or not they are may depend on environmental factors. For example, just after clear cutting the air is likely to have high levels of host volatiles, thus making any host volatile added to a trap ineffective. However, a company may make money by selling such volatiles, and hence they would tend to ignore any results that would lead to a loss of revenue. On the other hand, one could argue that they have the customers’ best interest in mind, because if host volatiles are important under some circumstances, it would be detrimental to remove them from the product.
This leads to my thoughts about the power of an analysis. The way I think of power is that it is a measure of the likelihood of finding a difference if it is there. There are two ways of increasing power that I can think of. One is to increase the number of replications, and the other is to use a higher alpha value. It is important to think about the consequence of an error. A Type I error is when significance is declared when there is none, while a Type II error is when no significance is found when in fact there is one. Which of these is most important is something we need to think about. For example, if you worked in conservation of a threatened species, and you found that a particular action to enhance survival resulted in a p-value of 0.07, would you be prepared to declare that action ineffective assuming that it wasn’t prohibitively expensive? If you have committed a Type II error, and discontinue the action, it could result in extinction of the threatened species. On the other hand, if you test a pesticide, would a significant value of 0.049 be enough to decide to pursue the expensive testing required for registration? If you have committed a Type I error, the product is not likely to succeed in the market place. If the potential market is small, which tends to be the case for behavioural chemicals, it may not be feasible to use this product because of the high cost, which has nothing to do with statistical analysis, but could be the overriding concern in determining the importance of the finding.
One area where the sole use of p-values can become very problematic is for regressions. The p-value only tells us whether or not the slope of the line is significantly different from zero, and therefore it becomes really important to look at how the data are distributed. An outlier can have a huge impact, for example (see figure). As an editor I saw many questionable regressions, e.g., with single points driving much of the effect, but which in the text were described as highly significant.
Fig. 1. An example of where a single point is driving a linear regression. Take it away and there is no apparent relationship at all. Figure from http://www.stat.yale.edu/Courses/1997-98/101/linreg.htm
Finally, we need to keep in mind that a significant p-value does not indicate certainty, but probability, i.e., at p=0.05, you would expect to get the same result 19 of 20 times, but that still means that the result could be the result of chance if you only ran the experiment once. (If you run a biological experiment that yields a p-value close to 0.05 a number of times, you would soon discover that it can be difficult to get the same outcome every time). Depending on the context, that may not be all that confidence inspiring. For example, if someone told you that there was only a 5% probability that you would be get seriously sick by eating a particular mushroom, wouldn’t that make you think twice about eating it?? On the other hand many of us will gladly shell out money to buy a 6/49 ticket even though the probability of winning anything at all is very low, let alone winning the jackpot, because in the end we are buying the dream of winning, and a loss is not that taxing (unless you gamble excessively of course). I consider odds of 1:8000 in a lottery really good, which they aren’t of course, evidenced by the fact that I have never won anything of substance! So relatively speaking, 1:20 is astronomically high if you think about it!
Why am I bothering to write this as a self-confessed statistics phobe? I have mainly to emphasize that you (and by « you » I primarily mean students engaged in independent research) need to think of statistics as a valuable tool, but not as the only, or even primary tool for interpreting results. Ultimately, it is the biological information that is important.
Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.
by Mischa Giasson
In 2008, l was asked to participate in a mark-release-recapture survey on the shores of Grand Lake, New Brunswick. My dad and I joined Fredericton entomologist Reggie Webster on a boat to visit three small sites among the rocky beaches surrounding the lake. We were searching for a rare, recently locally discovered beetle that is found nowhere else in Canada: the Cobblestone Tiger Beetle. This experience was the first of many that lead me to the realisation that a career in entomology was an option, fueled by my life-long fascination with insects (and other creepy-crawlies).
The Cobblestone Tiger beetle (Cicindela marginipennis) is an insect in the sub-family Cicindellidae (Coleoptera: Carabidae). This small, pretty beetle is listed as Endangered and placed in Schedule 1 of the Species at Risk Act (SARA), which means that the species has been deemed at risk and that there has been development and implementation of protective and recovery measures.
There is no doubt that Tiger Beetles live up to their namesake as extremely beautiful, but equally deadly predators. These beetles run down their prey by sprinting in short, quick bursts. In fact, they run at such high speeds that they temporarily go blind! One species has been recorded moving at 9 km/hr, which is almost 54 times its body length per second. Their antennae are used to prevent any collisions while sprinting and they have a very short reaction time, but they must make frequent stops to take in their surroundings and make sure they’re on the right track.
Both the adults and larvae are predators, the larvae employing a sit-and-wait approach: they wait in ambush from small vertical burrows in the ground, striking out at lightning speed to catch any prey that passes nearby. Prey consists of other insects as well as spiders, which stand no chance against the huge mandibles of the Tiger Beetle. The Cobblestone Tiger Beetle can be distinguished from other Tiger Beetles by the smooth, continuous cream-coloured border along the outer edges of the elytra and by a bright orange/red abdomen that is visible when the beetle is in flight. Their overall colour is most often a dark chocolatey brown, but some metallic blue and green individuals have been observed in the New Brunswick populations.
Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.
The Cobblestone Tiger Beetle gets its name from its choice in habitat. The eight sites in New Brunswick where it can be found are all cobblestone beaches. This beetle is also found along major river systems in the United States, from Mississippi to Alabama and from Indiana through to New England. Populations are quite small, few and far between. The Canadian population was discovered in 2003 by Dwayne Sabine and is the only known population to also inhabit lakeshore sites, likely due to the riverine characteristics of Grand Lake. There are three known sites on Grand Lake, while the other five are on the shores of small islands in the Saint John River between Woodstock and Bath. These cobblestone habitats are unique to areas with yearly spring flooding which keeps the vegetation from spreading along the beach, maintaining the flat areas of gravel and sand between the stones which are necessary for the larvae to make their burrows. Not much is known of the Cobblestone Tiger Beetle’s specific life history, but it is assumed to be similar to that of other tiger beetle species. The beetles have a two-year life cycle: eggs are laid individually in the sand, where the larvae will hatch and make burrows. The larvae overwinter in their burrows, somehow surviving the spring floods and emerging as adults in June.
Cobblestone Tiger Beetle. Photo by Stephen Krotzer, used with permission.
Due to their specific habitat requirements, Cobblestone Tiger Beetles are very vulnerable to environmental changes and disturbances. The biggest threat is habitat damage. In New Brunswick, the installation of the Mactaquac dam destroyed many suitable habitats both upstream and downstream. The small beetle populations are also quite vulnerable to over-collection by scientists and insect enthusiasts. The current concerns involve the use of off-road vehicles, as this leads to the alteration of suitable habitat and often directly leads to the death of many larvae present on the beaches. This threat applies mostly to the shores of Grand Lake, where there is increasing development and use of the beaches. The protective measures implemented include developing a stewardship plan, educating the local communities and encouraging their support and participation in the conservation of this special beetle. Decreasing human disturbance is the most important factor in ensuring the survival in our province of the already very small populations of the Cobblestone Tiger Beetle.
References
https://www.registrelep-sararegistry.gc.ca/virtual_sara/files/plans/rs_cobblestone_tiger_beetle_e_final.pdf
http://www.sararegistry.gc.ca/species/speciesDetails_e.cfm?sid=1031
Zurek, D. B., & Gilbert, C. (2014). Static antennae act as locomotory guides that compensate for visual motion blur in a diurnal, keen-eyed predator. Proceedings of the Royal Society of London B: Biological Sciences. 281(1779): 20133072.
CONTACTER LA SOCIÉTÉ
Assistant administratif : info@esc-sec.ca
SEC Président : ESCPresident@esc-sec.ca
This post is also available in: