Reflections on bee monitoring: The debate over lethal sampling

[Zach Portman]

Hi Beeple,

I wrote a post about bee monitoring and the debate over lethally sampling bees which may be of interest:

https://medium.com/p/320dd35e7b01

Zach

[Kit Prendergast]

Thanks Zach, I always love reading your stuff, it's always very thought provoking and you have a good critical understanding of the issues at play.

I should add I hate lethal sampling when the authors don't even identify the species. The point of lethal sampling is so that specimens can be identified (e.g. good luck trying to identify a 3mm Euryglossina alive in the field!). But if you're catching bees and just grouping them into genus or even worse, 'small black bees' , 'sweat bees' (all Halictids? unclear), 'reed bees', 'leaf cutter bees' (which usually means all Megachile even though only a subset cut leaves) then you shouldn't be lethally sampling at all, and if you can't ID to those groups by observation alone then you should do a course before you even start doing a bee study. My coauthor Katja Hogendoorn and I touched on these issues in a piece here:

https://onlinelibrary.wiley.com/doi/full/10.1111/aec.12998

(PDF attached for those without access).

Cheers

Kit

--
You received this message because you are subscribed to the Google Groups "beemonitoring" group.
To unsubscribe from this group and stop receiving emails from it, send an email to beemonitorin...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/beemonitoring/CAMZwbbOuoVN_0bjFqurV8Qf%2BwO7KgBwvz8bd3yawQwNQRS6u-g%40mail.gmail.com.

--

Dr Kit Prendergast

Native bee scientist, conservation biologist and zoologist

Curtin University and Forrest Scholar

ORCiD: https://orcid.org/0000-0002-1164-6099 

Research: https://www.researchgate.net/profile/Kit-Prendergast/research

YouTube channel The Bee Babette: https://www.youtube.com/c/TheBeeBabette 

'Creating a Haven for Native Bees': https://www.facebook.com/CreatingaHavenforNativeBeesBook/

Wild Bee artwork: https://www.redbubble.com/people/BeeBabette/explore?asc=u&page=1&sortOrder=recent

[Miriam Richards]

Hello all,

A recurring theme in critiques of pan trapping is that too many sweat bees, especially Lasioglossum (Dialictus), are collected.  Another theme is that bee ecology research is unbalanced - we need more population studies.  I certainly agree that we need more population studies, but as someone who has done population-level studies for decades (I guess I'm one of those "old and established" bee biologists mentioned in the article!), I can say with confidence that such studies are time-consuming, their success is dependent on finding enough bee nests to produce respectable sample sizes, and they don't get cited nearly as often as community studies.   

Pan trap studies can help to address the first two of these issues.  Pan trapped specimens allow us to study sweat bees when we can't find nests - which is true for most local species, most of the time.  We've shown that data from pan trapped specimens and nesting populations concur to a large extent in what we can learn about bee phenology, activity patterns, and breeding behaviour, because the abundance of foragers in pan traps correlates well with forager abundance inferred from observations at nests (eg L. Dialictus laevissimum: Corbin et al. 2021, Halictus confusus: Richards et al. 2010).  I find it ironic that pan trapping continues to be criticized for collecting too many sweat bees, especially Dialictus, while at the same time the counter-evidence that pan trapping can provide important ecological information on these bees, is overlooked.

For those of you with large pan trap collections, please consider using the specimens for population studies.  Pinned specimens can be rehydrated for dissection, and systematic (eg biweekly) trapping yields excellent information about phenology.  I think we could fill in a lot of gaps in our understanding of bee behaviour with specimens collected in mass trapping studies.  And such studies make excellent undergrad research projects because students can collect data on bee behaviour and phenology in the winter!

Cheers,

Miriam

Miriam Richards

Biological Sciences

Brock University

St. Catharines, ON Canada

---

From: beemon...@googlegroups.com <beemon...@googlegroups.com> on behalf of Kit Prendergast <kitprend...@gmail.com>
Sent: Friday, November 3, 2023 8:29 AM
To: zpor...@gmail.com <zpor...@gmail.com>
Cc: beemonitoring <beemon...@googlegroups.com>
Subject: Re: [Beemonitoring] Reflections on bee monitoring: The debate over lethal sampling

 

To view this discussion on the web visit https://groups.google.com/d/msgid/beemonitoring/CAN2D7pG-Q0Ko1vJTq2FqLvJgOCGcQMJBfN02EKZvD15RmPKyPw%40mail.gmail.com.

[Brian Dagley]

I agree with some of Miriam Richards' comments. I have a few observations about Zach's Medium post, which are also about his past related Medium post and co-authored publication that recommended against using bowl traps in bee monitoring studies. 

They mentioned in the earlier post that no authors had expressed disagreement with his recommendation against using bowl traps. At the time I read that, I realized that some and probably more than a few authors must disagree even if they didn't publish responding articles or replies. The recommendation against using bowl traps arguments in large part seemed to portray bowl traps as being used alone in studies, vs. many studies not only combine bowl trapping with netting, but also combine those with taking photographic records, visual observations, mark recapture, etc. Although, the posts did also make a few mentions of combined collection methods and how each method has a set of biases. They frequently mentioned bumblebee-specific monitoring, e.g. in the context of mark recapture, or collecting photographic records (e.g. uploaded to bugguide or inaturalist), yet it's well known that any Bombus-focused study shouldn't extensively use bowl traps, because bowls mostly catch different bees with small or medium body sizes. For that reason, I consider some of the arguments about Bombus studies to be separate from studies that focus on all bees or only on small halictid bees, and so not necessarily a refutation of the latter.

I agree that the described "taxonomic bottleneck" is real, although that seems to partly be a different domain of consideration, e.g. related more to practicality. Certainly, if authors weren't able to identify or store their Dialictus specimens that would be a problem. Although, many studies identify those specimens as far as they can but leave some at subgenus rank or use "c.f." It's been said that there are only a handful of Dialictus identification experts. So, it may be good advice that most authors including most beginners could be better off not dealing with that bottleneck, but I'd make an exception for studies conducted by Dialictus experts or by other authors who Dialictus experts identify for. Some of the arguments seemed to come close to saying bowl traps don't work to use in monitoring at all, and/or would only return biased results. It's well known that every existing collection method including non lethal methods have certain biases. Which seems to be part of the basis for many studies using combined methods, and for noting biases and limitations and trying to correct for them in their analyses. If anyone were claiming bowl traps can't tell us anything in monitoring, that seems insufficiently proven by examples/evidence, despite that some articles were cited.

They also seemed to argue that the entire community should take this view of turning away from bowl traps for monitoring. By contrast, it may be informative and useful for a diversity of different approaches to be used by different authors in studies, or at least for a small percent of authors who are informed of bowl biases and the taxonomic bottleneck to still use trapping, including to fully identifying the Dialictus specimens, etc. I agree that it may be best for the whole community to become better informed about these matters and to consider not using bowl traps, but at the same time it shouldn't be a problem if select experts who do identify their specimens do use bowls, to some extent, e.g. in combined collection method studies. Re: lethality considerations, these like the taxonomic bottleneck consideration seem to be in a different domain of consideration from the rest of the arguments, but are still worth (mostly separately) considering. It would seem that nearly everyone would agree with the recommendation to reduce the number of specimens collected where possible, to only collect the number of specimens necessary. One possible conflict is that some of the mentioned studies did intentionally use high sample sizes, yet regarded them as necessary or useful. 

The arguments suggest that maybe some of those studies killed too many bees or even the declines those authors found. That concern is real, although is also very difficult to prove has occurred, so it may be ideal to emphasize that as more of a possible concern than a mistake certain authors definitely committed. Overall, I at least partly agree with most of their arguments. But, I regard such arguments to be more like optional recommendations of what methods would be ideal for more (but not all) authors and students to shift to use, and where part of the main argument is using practicality considerations (e.g. avoiding the taxonomic bottleneck). I also agree that minimizing or in some study contexts avoiding lethal collection is ideal where/if possible. I have another survey example that could be considered. I helped the 2017 to 2022 NYS pollinator survey (ESNPS), collecting specimens in the early years with bowls and netting (also as part of a thesis) but shifting to mostly only non lethal photographic records in the final years. The study was designed by bringing in multiple bee experts and had a large number of participants and occurrence records. The methods included bowl trapping and netting (unsure if if vane traps were used) and photographic records, and many participants chose to only take photographic records. That survey wasn't only a monitoring study, it also was based on enlarging the previously known state checklist of bee species, although monitoring was also part of their goals.

I didn't conduct their monitoring analyses, and like a few others I know wasn't offered authorship on that survey's final report. As one side note, when the report was published I noticed a few out-of-range species, which John Ascher and Joel Neylon agreed seem to be errors. Leaving those few species aside, I don't know of any publications that criticized the ESNPS monitoring results. The following link has links to their report and to additional appendix documents: https://www.nynhp.org/projects/pollinators/. I'd be interested to learn whether Zach and his co-authors or others would consider that survey to have produced accurate results "despite" that it partly used bowls. In addition, I'd recommend giving a similar reading and review of other recently published or ongoing US bee surveys that used bowl traps as one of multiple collection methods.

Brian

To view this discussion on the web visit https://groups.google.com/d/msgid/beemonitoring/YQBPR0101MB46664627FB4FBE59E9303A89ADA5A%40YQBPR0101MB4666.CANPRD01.PROD.OUTLOOK.COM.

[David Cappaert]

[Douglas Yanega]

On 11/7/23 2:29 PM, David Cappaert wrote:

--

Are you trying to trigger the pedants like me by posting this?

rufous means "reddish" 

fuscous means "dark, ranging from black to brown"

fulvous means "amber or tawny yellow"

piceous means "pitch black"

ochraceous means "ochre-colored" (a pale yellow in Greek, but subsequently adopted as a somewhat dark yellowish orange) - https://en.wiktionary.org/wiki/ochre

testaceous means "brick-colored", and I think we won't ever get people to agree on what color bricks are. I'd be inclined, myself, to use terracotta as the more precise term - https://en.wiktionary.org/wiki/terracotta

Lots of ambiguity there.

Peace,

-- 
Doug Yanega      Dept. of Entomology       Entomology Research Museum
Univ. of California, Riverside, CA 92521-0314     skype: dyanega
phone: (951) 827-4315 (disclaimer: opinions are mine, not UCR's)
             https://faculty.ucr.edu/~heraty/yanega.html
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82

[James Cane]

Hi David- you've initiated an enlightening discussion here. I generally am not in the business of describing bee colors (but for a Eucera key I posted for the Great

Basin fauna). However, like many of us, I do often encounter color names as well as terms for surface sculpturing in the keys that I use. I suspect that is where most folks will encounter the need to understand the nuance without pausing their work with the key to flip on their computer and go online go to a color chart or the like and see what, say, LaBerge meant by fulvous hairs or a shagreened prothoracic surface on an Andrena, to only then lose their place in the key! To that end, a user could print your clever (and quickly composed!) image, or have it on their cell phone, for quick reference until the terminology is committed to memory.

jim

On Tue, Nov 7, 2023 at 3:30 PM David Cappaert <davidc...@appliedeco.org> wrote:

--
You received this message because you are subscribed to the Google Groups "beemonitoring" group.
To unsubscribe from this group and stop receiving emails from it, send an email to beemonitorin...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msgid/beemonitoring/CACmzQnqo5j32gTsfB8V6fc3mWOLwP3JVFYPJ2xBbTws740wFDg%40mail.gmail.com.

--

James H. Cane

Native bee and pollination ecologist

Emeritus USDA-ARS Bee Lab, Logan, Utah

owner -  WildBeecology

https://www.researchgate.net/profile/Jim-Cane

https://www.zotero.org/jimbee

https://sites.google.com/view/jimcanewildbeecology/home

"Knowledge and comprehension are the joy and justification of humanity"
 Alexander von Humboldt

[Jack Neff]

I don't agree with Doug on all his definitions but the colors on that poor gaudily spray painted Anthophora are only vaguely in the ballpark for historic color name usages.  I would not want to see them widely adopted.

Jack

John L. Neff Central Texas Melittological Institute 7307 Running Rope Austin,TX 78731 USA 512-345-7219

To view this discussion on the web visit https://groups.google.com/d/msgid/beemonitoring/CAJu7%2BBnAknHpVxX--60%2BMjZhevzX0B9Q72aQFvLdQF9LMFqVMA%40mail.gmail.com.