HUB Robeson Center Exhibit

The Frost Entomological Museum was selected to exhibit some of the collection in ‘Eclectic Collections’ at the HUB Robeson Center on Penn State’s University Park Campus. Hopefully, we can draw Penn State students, staff, and visitors to our exhibit while it is up through January. Since our current museum space is open by appointment only, we felt this was an excellent opportunity to still showcase the insects in our collection!

Photograph of a display of some examples of extreme insects, on display at the HUB Robeson Gallery at Penn State

Image of the “Insect Superlatives” display at the HUB Gallery. Photo by Frost Entomological Museum at Penn State (CC BY 2.0). Click for source.

Our exhibit, titled Insect Superlatives, features extremes in entomology. The following is the information about the specimens in the exhibit:

Insect Superlatives, Curated by Emily L. Sandall, Frost Entomological Museum at Penn State

Comprising an estimated 6 million species, the insects are the most diverse group of animals on the planet1. Entomologists can study insect diversity using museum specimens to examine patterns in space, time, and appearance. Penn State is home to one of these collections, the Frost Entomological Museum, which houses insects collected in Pennsylvania and beyond over the last 150 years. Of all the diversity of the insects, here are some who represent extremes in entomology.

A. Most valuable | Honey bee | Apis mellifera Linnaeus, 1758
Pollinators, such as the honey bee, provide annual global food production services that value between $235 and $577 billion6. A number of factors, including climate change and insecticides have been linked to pollinator loss over the last decade.

B. Smallest | Parasitoid wasp | Dicopomorpha echmepterygis Mockford, 1997
This wasp would like dust on this paper triangle, at around 140 µm in length9; we show the photo of this microscopic wasp instead of an insect specimen. Parasitoid wasps lay their eggs in or on other insects and arthropod hosts to develop as larvae, emerge as adults, and repeat the process.

C. Largest mass | Goliath beetle | Goliathus goliatus (Drury, 1770)
At a maximum weight of around 100 grams, this beetle species, native to Africa, is considered to have the largest mass of the insects.

D. Largest wingspan | Atlas moth | Attacus atlas (Linnaeus, 1758)
The atlas moth has a wingspan of up to 27 cm and lives throughout Asia5. Only the caterpillar stage feeds; adult atlas moths live off of the energy stores of their youth.

E. Most painful sting | Tarantula hawk | Pepsis sp. Fabricius, 1804
The tarantula hawk is a wasp that stings its spider prey in order to use it as a host for its larva. Justin Schmidt, a Penn State alum who created a sting pain index described it as ‘instantaneous, electrifying, and totally debilitating’ for humans, warranting its second place ranking on his index8.

F. Most deadly | Malaria mosquito | Anopheles gambiae Giles, 1902
Female Anopheles can transmit the malaria parasite, causing an estimated 200 million cases of malaria each year between 91 countries2.

G. Longest migration | Wandering glider | Pantala flavescens (Fabricius, 1798)
The wandering glider, the longest-migrating insect, is a dragonfly that migrates an estimated 14,000-18,000 kilometers across the Indian Ocean3.

H. Fastest | Tiger beetle | Cicindela sexguttata Fabricius, 1775
Tiger beetles are among the fastest recorded insects, running at a speed of over 50 body lengths per second, 50x faster than the fastest human sprinters7.


1Stork, N. E. (2018). How many species of insects and other terrestrial arthropods are there on Earth?. Annual review of entomology, 63, 31-45,.
2World malaria report 2017. Geneva: World Health Organization; 2017. Licence: CC BY-NC-SA 3.0 IGO.
3Troast D, Suhling F, Jinguji H, Sahlén G, Ware J (2016) A Global Population Genetic Study of Pantala flavescens. PLOS ONE 11(3): e0148949.
4Forbes, A. A., Bagley, R. K., Beer, M. A., Hippee, A. C., & Widmayer, H. A. (2018). Quantifying the unquantifiable: why Hymenoptera—not Coleoptera—is the most speciose animal order. bioRxiv, 274431.,
5Pavid, K. (2016). Spotlight: the atlas moth. The Natural History Museum., 6Pollinators vital to our food supply under threat. Food and Agriculture Organization of the United Nations.,
7Gilbert, C. (1997). Visual control of cursorial prey pursuit by tiger beetles (Cicindelidae). Journal of Comparative Physiology A, 181(3), 217-230.,
8Schmidt, J. O. 1990. Hymenoptera venoms: striving toward the ultimate defense against vertebrates, pp. 387-419. In D. L. Evans and J. O. Schmidt [Eds.], Insect defenses: adaptive mechanisms and strategies of prey and predators. State University of New York Press. 9Jerry E. Gahlhoff, Jr. (1998) University of Florida Book of Insect Records Smallest Adult Jerry E. Gahlhoff, Jr. Chapter 38 Smallest Adult.


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Point-mount adhesive follow-up

My previous post about adhesives used to prepare specimens appears to have started a constructive dialog in social media. I want to address a few points that were raised there. Some quick context first: Entomologists really want their specimens to be

  1. archival – they should last a long time with very little change
  2. reversible – we can undo the specimen to further examine it
  3. easy to make – we have a LOT of insects to make into specimens

In my recent review, available now as a preprint, I argue that our preferred adhesives fail in one or more of these properties. I did my best to offer some alternatives to specimen mounts that do not use adhesives, and it’s clear that these also have problems (many of which are also in the review).

Minuten pins, for example, are difficult to handle and require a lot of time and patience to master. One colleague summed it up best—”your comment on minutens leads me to conclude that you are %$^#& insane”—although he didn’t censor the language. I know from personal experience that there is always that one wayward minuten that gets on my shirt, that I can never find but which I feel poking me throughout the day. Ugh. Minutens won’t work as a total replacement for points anyway, as many specimens are still too small for even these diminutive pins.

After writing the review I had convinced myself that preservation in fluid (ethanol) was probably the best solution, but many people raised concerns on Twitter about impacts of preservative on cuticle, the effects of impure (denatured) ethanol, and bleaching of specimens. We have a long history of preserving organisms in “spirit”, and I suspect many of these issues have been or can be solved with clear, pure ethanol. Most of the examples I saw in social media concerned situations where the ethanol percentage was likely too low to preserve the insects (trap residues that rotted) and/or there were simply too many specimens and all their associated chemistries in close contact. Fluid preservation has other problems, of course, which are mentioned in the review.

A third option that people haven’t yet raised, as far as I can tell, is to eliminate the requirement that these mounts must be reversible. Plenty of adhesives are archival and easy to use but difficult or impossible to reverse, at least with solvents. In some cases they can be mechanically “reversed”. Maybe that’s the route we go.

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Point-mount disenchantment

Point mounts are my bread and butter. The wasps I study usually cannot be pinned—they’re too small—so we affix them to tiny triangles punched from archival card stock, skewered on a pin. The technique is pervasive, as the entomological collections community as a whole makes >400,000 such specimen preps annually. Check out this video from a collections master, Ed Riley of Texas A&M:

This is pretty much how I’ve done it, for 20 years. He uses Elmer’s Glue-All and clear nail polish, but, as hymenopterist tradition dictates, I preferred shellac or fish glue (Seccotine). Only recently have I started folding archival white glues (polyvinyl acetate or PVAc) into the process for certain insects.

A few weeks ago I wrote about how our use of these adhesives was questioned by a visiting museum conservation expert. The subsequent discussion inspired me to survey the entomology community for two main pieces of information: (1) What properties do we consider to be important for adhesives used in this context. Is there consensus? And (2) what adhesives do we use? With the results in hand, I dove into the polymer chemistry and museum conservation literature for information that would help me determine whether our chosen adhesives match our required properties.

A first draft of my review is now available:

Deans AR. (2018) A review of adhesives for entomotaxy. PeerJ Preprints 6: e27184v1 DOI: 10.7287/peerj.preprints.27184v1

As a community we pretty much agree on which adhesive properties are important, with the top three being: (1) archival, (2) reversible (many responded that this was equally important to “archival”), and (3) easy to use/prepare. We also appear to employ three main types of adhesives: (1) polyvinyl acetate (“white glue”), in various forms, (2) clear nail polish, and (3) shellac, with a few others types used less frequently.

My subsequent adhesive review, I have to admit, has thrown me into an existential crisis. All of our adhesives are critically flawed, and, if you trust the literature from other domains, we are generating hundreds of thousands of curatorial problems each year.

There are a lot of caveats, of course. The physics and chemistry at this small scale—a tiny dot of adhesive, securing cuticle to card—may be quite different from, say, coating the back of a canvas with a thick dollop of PVAc. And I certainly do not want to discount the vast experience of experts who have had to deal with point mounts and the real process of reversing them. We definitely need more rigorous research here, based on objective observations and data.

Given those caveats, however, I think I can comfortably make two solid recommendations:

  1. Stop using Elmer’s for point mounts! It is not archival, it doesn’t age well, it remains acidic, and the formula is proprietary and changes over time, sometimes radically. When I told a group of collections experts recently that most of my colleagues used Elmer’s for specimen mounts they audibly gasped and followed up with soft, awkward laughter and a lot of head shaking
  2. Stop using cellulose nitrate-based (“nitrocellulose”) clear nail polish for specimen repair and point mounts. Its aging properties are worse than Elmer’s, and these joints will ultimately fail (almost definitely within our lifetimes)

Other recommendations I am pretty sure will hold up upon further research:

  1. Stop using shellac for point mounts. Shellac bonds are very difficult to reverse, and the joints will become brittle with age
  2. Stop using PVAc (AYAF, AYAT, AYAC, Gelva, etc.) for these mounts. They age poorly, as poorly as Elmer’s, and will accumulate dust and debris over time

We’re doing more research, including some chemical analysis of other adhesives. Overall, though, I’d say I am disenchanted with this type of specimen prep. I might just move to minutens for some specimens or stick to ethanol. If you’re looking for an adhesive with proven long term archivability (but not easy reversibility) I’d look at this class:

  1. Poly(ethylene-vinyl acetate) (PEVA) coplymer, like Jade 403 or Evacon R.

They age well and are considered archival. Keep in mind, however, that these adhesives have a very short shelf life (six months) in the bottle. (This is true of any PVAc dispersion!) The set adhesive will also likely accumulate dust and debris over time and ultimately will be difficult to reverse. Another one worth experimenting with:

  1. Paraloid B-72 acrylic copolymer. It is a known archival material, with proven reversibility. You can buy it in prepared tubes or make your own, from beads dissolved in acetone or ethanol

We’ll have a lot more to say at the Entomological Collections Network meeting in November, including more on animal-derived adhesives (hide glue, etc.), Martha Stewart clear gel, gums, and others. Stay tuned!

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Natural History Observations: Wasps on Red Maple

While kayaking in Holland, Massachusetts, I paddled under the branches of a tree that had fallen into the river, and realized too late that it was completely covered in wasps. I made it through unstung, but paddled back for a second look.

There were several wasps, but no obvious nest. Something interesting was that there were several different kinds of wasps; not just vespids like yellow jackets (Vespula spp.) and bald-faced hornets (Dolichovespula maculata), but also some pompilids. What were they doing?

The Red maple I paddled under, before realizing too late that it was covered in wasps. Photo by Carolyn Trietsch (CC BY 2.0). Click for source.

I watched one Vespula spp. crawl across the top of a leaf, buzz over to the next to repeat the process, then so on and so forth, working its way up the branch. It was systematic in its efforts, covering every single leaf on that branch before moving onto the next. The other wasps did the same, as if searching the leaves for something (see video below).

I later identified the tree as a red maple, Acer rubrum, also known as swamp or water maples (fitting for where I found it). A quick online search revealed that many others have seen wasps crawling on leaves of red maple that were infested with scales, psyllids, aphids, and other insects that produce honeydew, which attract wasps like vespids and pompilids.

Natural history observations tend to be underplayed in our research, but simple observations such as these can generate important questions about behavior, ecology, and more. The day I made these observations was cloudy and cool (about 70°F), and I observed this behavior around 3:00PM. I passed by the same branch again on a few sunnier, warmer days (about 80°F) but did not see as many wasps. Did the wasps forage until they exhausted the supply of honeydew? Did they have greater energetic needs on a cooler, cloudier day than on a sunnier one, and change their foraging behavior in response?

As a new fall semester starts and a new session of ENT 432: Insect Biodiversity and Evolution begins, we have our students do an activity called “Your Inner Darwin”. Students are instructed to watch a small patch of nature for an hour, record their observations and collect the insects they see. In doing this activity, we hope to show our students how much can be gained from observation, even if it’s something as simple as watching wasps on branch.

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2018 Entomological Collections Management Workshop in San Francisco, California

Last week, I attended the 2018 Entomological Collections Management Workshop, held at the California Academy of Sciences (CAS) in San Francisco, California. This was an intensive 4-day workshop run by the Entomological Collections Network (ECN) aimed at educating and training both current and future managers of insect collections.

Topics  included profiling and assessing collections, writing plans and mission statements, managing museum pests, packing & shipping specimens, supervising museum staff, digitizing and georeferencing specimens, and much, much more. We covered an impressive amount of material in four days, considering that we could have easily spent entire semesters on some of the topics. We were certainly not left lacking—each museum participant was sent home with a flash drive with hundreds of additional resources. I certainly have a lot more reading to do….

As part of the workshop, we learned how to package specimens for shipment. To test how well we did, we threw our boxes off of a three-story building. These specimens survived! Photo by Carolyn Trietsch (CC BY 2.0). Click for source.

Some of the greatest takeaways and pieces of advice from the workshop were as follows:

The Collection is everything

As David Furth put beautifully, “collections are the heart of a museum.”

Regardless of a collection’s size, scope or regional focus, all natural history collections are irreplaceable resources that are important on a local, national and international scale. Natural history collections can be used in many, many different ways; not only are they valuable for research and education, but also for environmental and conservation planning, resource management and allocation, and public policy and decision making.

Collection managers do it all

Collection managers are curators, supervisors, building managers, storytellers, exhibit designers, administrators, and more. To do these tasks effectively, they must know a little bit about everything. It’s easy to get caught up in different aspects of the job, but collection managers must never lose sight of the most important thing: the collection.

Collection management is a balancing act between preserving specimens and allowing them to be used and accessed for research or education. Collection managers have to know the needs of the collection as well as the needs of those using the collection, whether for research or other reasons.

As much as you want to please everyone, sometimes it is necessary to say no, whether it concerns accepting a donation of specimens that does not match the aims of your collection, or a request for destructive DNA extraction on specimens that cannot be replaced. Collection managers must strive to find the balance between protecting the collection and allowing it to be used.

The ethanol collection at the California Academy of Sciences. There are many things that collection managers must take into consideration when planning space for a collection such as this. Each shelf has a bar to prevent jars from falling off in the event of an earthquake, which is more likely in San Francisco than in State College, PA. The fire system in this room is also very sensitive (important for when your collection is highly flammable), and will fill the room with a dense fog at the first detection of smoke or heat. Photo by Carolyn Trietsch (CC BY 2.0). Click for source.

Know how your collection is used

It is important to track how your collection is used. Every bit of data you can collect will help you convince administrators that your collection is important and worthy of funding. Some of the things that can be recorded include: the number of resident researchers, students, and volunteers working with the collection; the number of visitors a year, and how many tours were given; the number of papers published using specimens from the collection; the number of loans and acquisitions; even the number of emails or phone calls you get expressing interest in the collection!

One handy tip from the workshop was to keep a counter handy at public outreach events so you can keep track of how many people you talk to and educate about the collection. Another handy tip was to keep a logbook available in the collection for visitors to write in. Any activity you track can help prove to others how useful collections are, and help prevent your collection from becoming orphaned in the future.

Learn about other collections at your institution

As part of the workshop, we toured collections of invertebrates, vertebrates, fossils, and plants, not just for the spectacle but because any entomology collection manager will be working with other collection managers, who may have different needs or concerns based on the specimens they have and the ways those specimens are preserved. Other collection managers may have goals that align with or contradict your own; it is important to understand how their collections operate and how their needs differ from yours so you can work to resolve any potential issues that arise, such as with space for the collection (“space wars”) or chemical safety (for example, some taxidermied vertebrates were preserved with arsenic and are dangerous to touch).

As part of the workshop, we toured several types of collections, including collections of fossils. Check out this saber-toothed tiger (Smiledon) fossil pulled from the La Brea Tar Pits. Photo by Carolyn Trietsch (CC BY 2.0). Click for source.

Know the ins and outs of designing exhibits

There are challenges associated with using specimens in exhibits. These include exposing specimens to damaging conditions such as light, temperature and humidity fluctuations, and the unavoidable hazard of small children touching and banging on the exhibits.

You should never subject research specimens to these conditions—instead, have a separate teaching or outreach collection you can take specimens from. Also, when designing an exhibit, decide what the aim of the exhibit is and make sure each component fits in with the overall theme. Each exhibit should tell a story to the visitors that they can walk away with and pass onto others.

Learn how to communicate with the public

Collection managers often serve as the public face of the museum. Collection managers are the ones who will be giving tours, participating in outreach, designing exhibits, interacting with traditional and social media outlets, and answering questions about the collection.

Think about what the public is interested in (have “oh my” stories or specimens ready; anything that makes people say “oh my”) and stay aware of current events—you will likely be asked about them. The public will likely ask questions about the collection and where the specimens came from; they may also ask questions about you and what your job is. Be patient and never say things that you know are wrong. If you’re asked a question you don’t know the answer to, tell them so, then look up the answer later and follow through with the person who asked it. They will respect that you were honest and took the time to follow through with them, and they will remember you for it.

Some examples of “Oh my” specimens at the California Academy of Sciences– mosaic gynandromorphs (containing both male and female wing characteristics) of Speyeria cybele eileenae. Photo by Carolyn Trietsch (CC BY 2.0). Click for source.


Though I have gained a lot of experience in imaging, digitizing and managing insect collections during my time at the Frost, the ECN collections management course helped me take this to the next level, gaining a broader view of the field and helping me to fill in the gaps in my knowledge. This course definitely helped me become a more capable and effective collection manager.

The workshop was held at the California Academy of Sciences (CAS) in San Francisco, California. The museum has a huge public space, complete with an indoor 3-story rain forest and an aquarium including a network of interconnected coral reefs! Photo by Carolyn Trietsch (CC BY 2.0). Click for source.

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