Frost Curators' Blog

Musings and miscellanea from the Frost Entomological Museum

New spider course!

Bob Snetsinger used to teach a course on spiders here at Penn State. It was offered in the summer, and, based on stories several alumni relayed to me, the course was very popular. Bob was able to inspire a passion for spiders in these students that has lasted for decades. (Steve Tessler, for example is an alum of this course)

I include a bit about spiders in my annual insect diversity course, but the treatment always felt superficial. After much rumination, reading, and discussion, I am excited to announce that Eric Yip and I are finally offering an updated version of Snetsinger’s famous spider course this fall! More details are below, and, like usual, I hope to post updates and some course materials here soon.

Spiders (ENT 497, 3 credits)

Fall 2021

This course is designed to grow students’ knowledge, understanding, and appreciation of spiders. Topics include spider taxonomy and how to recognize species; evolutionary history and relationships to other arachnids; the behavior and ecology of spiders as they relate to foraging, reproduction, and avoiding predation; cultural impacts and public attitudes regarding these organisms. The lab portion of the course focuses on understanding diagnostic and adaptive traits (spider morphology) and also how spiders can be used as indicators of habitat type and quality. Upon completing this course students should be able to:

  • Draw a typical spider and label the parts relevant to taxonomy and evolution
  • Describe patterns of spider diversity, as they relate to species numbers, evolutionary innovations, and geography
  • Identify many of the common spiders of central Pennsylvania
  • Explain how spiders have been used to understand behavior, ecology, and evolution more broadly
  • Describe how spiders can serve as habitat indicators (e.g., as indices of biological integrity), including the sampling protocols involved 
  • Leverage public fascination (and fear!) of spiders for science outreach

Instructors

  • Dr. Andrew R. Deans (adeans@psu.edu)
  • Dr. Eric Yip

Schedule

Wed / Fri 2:30–5:30pm

Find out More

https://psu.instructure.com/courses/2125004 (requires PSU Access ID)

Insect Biodiversity and Evolution (ENT 432) – 2018 edition

It’s that time of year again! The fall 2018 semester has ended, and I have another ENT 432 immersion to macerate and digest. As posted here before (see my 2016 summary and 2017 reckoning), I like to make notes-to-self at the end of the semester, while the experience is still fresh in my memory. Most of these issues are also at GitHub albeit with a bit less introspection. Here goes …

Darts ☹️

Let’s start with a few things I need to improve. This list seems to get shorter every year, which is good!

  • Death by slideshow – It’s time to simplify the slideshows that accompany each lecture and get back to using the whiteboard. A couple times this semester I tried to shift into lecture and sketch mode, and I realized how much I rely on slides to (usually less effectively) convey the message for me. Even my handwriting has deteriorated over the years. Part of the problem has been the rooms assigned to my class in the past, which had but one whiteboard that was always covered, in part, by the screen. This year’s room, which was in the newly renovated Ag Engineering building, was a masterpiece, with 360º of whiteboard space. See the photo below. Action items: illustrate lectures with 4–8 slides max, and only then to provide inspiring images of natural history in action or of complex synapomorphies or diagnostic traits (no text!). Make these slides available at the course website.
  • Draw the phylogeny – I always ask my students on the final exam to illustrate the phylogeny of insects and then to map various traits, key opportunities, patterns of diversity, etc. that are further discussed in an essay. I have always provided the phylogeny, which is a slightly modified version of Misof et al. (2014), as a PDF handout on day one and open every lecture with it. The students know they will need to reconstruct it as part of the final – and maybe during their qualifying exam – so we discuss it frequently. Their strategy is often to regurgitate the tree, using mnemonics and other tricks, rather than to think critically about patterns of evolution, including alternative relationships and the evidence for them. This year we tried to draw the phylogeny on the whiteboard using our memories, and it was fun! See photo below. Action item: Open each lecture with freehand illustration of tree, and be sure to add a time scale. Jettison the PDF.
Photo of recently renovated classroom, where desks are ensconced in whiteboards. Students are working in small groups at each whiteboard - one at each wall - to draw the phylogeny from memory
ENT 432 students work in groups to reconstruct the timing and pattern of hexapod evolution. Photo (CC BY 2.0) by Andy Deans. Click for original
  • Provide iterative feedback – This course has a lot of moving parts, and I have tried various approaches to providing feedback to students on their collections, databases, field notebooks, etc. I want to make sure that their end products are substantial and contribute maximally to the greater research enterprise. I also don’t want students to get any nasty surprises when it comes to grading time. I tried requiring mid-semester collection checks in the past with mixed success, and this year we moved to a volunteer system – we’re hear to help when you need us! Action item: Require iterative checks (one each?) of collections, field notes and databases. Consider developing a simple rubric and grading these iterative checks.

Laurels 😊

  • The collections were great! I feel a bit like Goldilocks, after trying collections that were too large (stressed students out, resulted in poor preps) and too small (this is an advanced class and a core course for entomology grad students!) I finally found a formula that was just right. The preps were, by and large, immaculate, and the diversity of each collection was rich enough to keep me interested.
  • The discussions were great! I definitely want to replace a few of the papers, but the students seemed engaged and (often) inspired. (Note to admissions committee: keep admitting great students!)
  • The natural history exercises were great! After last year’s experience we developed a scavenger hunt of sorts – short experiences with insect natural history that students would record in their field notes. I also shortened the immersive experience from three to two hours, which I have mixed feelings about. Altogether I feel like the Discover your inner Darwin exercise is about where I want it.
  • I had a great TA! Adam perfectly complemented my skills and made up for my weaknesses. He was always there when students needed him and gave a great lecture on Coleoptera. Thanks, Adam!
small plastic bowl catching wasps in a sand dune. it is partially filled with soapy water
Pan trap in the “dunes” at Powdermill Nature Reserve. Photo (CC BY 2.0) by Andy Deans. Click for original

As usual, Powdermill Nature Reserve was a great place for a field trip – excellent facilities and a variety of interesting habitats. I highly recommend this venue and would love to team up with another course for a combined experience! I am open to any ideas, including teaming with a botany, mycology, vertebrate or other course where students strive to interact with nature. We always make gourmet meals, in case you need another incentive to share the experience with us … Send me an email!

students outside a wooden dorm or lodge, collecting insects at a sheet that hangs from rope. it is night time
Catching insects at the sheet. Powdermill Nature Reserve, Raven’s Roost. Photo by Andy Deans. Click for original

Illustrating Metamorphosis with Maria Sibylla Merian

This post is the fifth in a short blog series featuring important figures in the history of natural history.

Maria Sibylla Merian is considered one of the most important naturalists of the 17th  century. Though she was well known during her lifetime due to her family’s successful publishing company, one of the largest at the time, her continuing fame and influence is due to her meticulous illustrations and insights into insect development.

Her stepfather, a still-life painter, recognized her artistic potential at a young age and began to train her alongside his own students. She learned how to draw, paint and make engravings on copper under his instruction, skills that few women at the time possessed. She published plates in books about flowers, but her focus soon turned away from flowers and towards the insects that dwelt on them.

Merian was fascinated with insects from a young age, and enjoyed collecting live caterpillars to rear into butterflies. As her artistic skills progressed and her reputation grew, the wealthy and elite would invite her to view their private gardens and illustrate the plants they maintained. As she did this, Merian took the opportunity to observe and illustrate the different types of insects associated with each plant.

A male (bottom left) and female (top left) Papilio androgeus butterfly, with caterpillar and pupal case. Illustration by Maria Sibylla Merian (1647-1717), illuminated copper engraving by P. Sluyter from Metamorphosis insectorum Surinamensium, Plate XXXI (c. 1705). Image from Swallowtail Garden Seeds (CC BY 2.0). Click for source.

Illustration is a meticulous process, requiring a great deal of time and effort. Trying to translate a complex three-dimensional object into a two-dimensional representation requires a different kind of thinking, but taking such an approach can cause someone to see qualities they did not notice before and gain a deeper understand of what they are looking at.

This is why drawing can be a helpful exercise for students studying anatomy and natural history. This is also what made Merian such an effective naturalist: her background as an illustrator, combined with her passion and dedication to the natural world, led her to realize that insects are not the product of spontaneous generation. Instead, Merian was among the first to show that insects have different life stages and undergo metamorphosis.

Merian created beautiful illustrations of insects, showing their larvae, pupae and adult forms as well as their hosts and habitat. Her illustrations are so detailed and accurate that many of the insects she drew can be identified down to genus and species. She observed how some caterpillars with different coloration and different host plants still had the same adult forms, constituting some of the first observations on generalist and specialist species in Lepidoptera. She distinguished between nocturnal and diurnal species, and even observed parasitoids, proposing that flies laid eggs on caterpillars and developed inside them instead of just spontaneously generating. She published her observations and illustrations in Der Raupen wunderbare Verwandlung und sonderbare Blumennahrung, which can be translated as The Caterpillars’ Marvelous Transformation and Strange Floral Food.

When she was 52, she financed her own trip to Suriname in South America, something that was almost unheard of for a woman of her age at the time. She desired to travel to South America so that she could observe insects and other animals in their natural habitats. She was forced to return to Europe after she contracted malaria, but in the two years she stayed in South America she was able to illustrated 60 species of plants and 90 species of animals. Some of her illustrations are the only known records of those species—it is likely that those species are now extinct. The product of her travels was the Metamorphosis insectorum Surinamensium, which is regarded as her most famous work.

Today, Merian is remembered for her beautiful illustrations of insect life stages and her notes on metamorphosis. Though Merian never received formal training as a scholar or scientist, her training as an illustrator allowed her to follow in Aristotle’s footsteps and make several insightful discoveries about the natural world.

 

Special thanks to Shelley Whitehead for her help with this post!

Observing insect natural history

Have you ever spent time carefully observing the insects that dwell on the surface of a pond? Water striders, water measurers, water treaders, and the like?

many tadpoles near the surface of the water in a pond. the insect is piercing its mouthparts into one
Waterstrider (Gerridae) feeds on a larval amphibian. Photo (CC BY-NC-ND 2.0) by Daniel Frost. Click for source https://flic.kr/p/bT9v8Z.

Last time I visited Powdermill Nature Reserve I laid myself down on the dock near the Avian Research Center and spent about 10 minutes watching insects. The experience was peaceful, inspiring, and intellectually stimulating. Gerrids chased each other incessantly, while midges floated by and backswimmers danced up and down the water column. I reminded myself about how semiaquatic insects are able to exploit their morphology to skate across the surface, and I wondered about their territoriality. What kinds of simple manipulations could I do to their environment to make relevant observations?

In an earlier post I mentioned the idea of encouraging my ENT 432 students to several short exercises in natural history observation—what Emily referred to a “mini-Darwins”, in reference to the longer exercise the students must complete (See this post by Rafa, for example). I thought I would share my short (so far) list of candidate experiences, designed to get my students’ feet wet. How many of these have you done in your life? Can you think of others that aren’t on the list?

  1. Go for a walk at night and listen for singing insects. How many different songs do you hear? Track one of the songsters down and observe it singing. Was it easy to find? How does it sing? Be sure to collect it.
  2. While on your night walk turn off your headlamp / flashlight and allow your eyes to adjust. Can you find any bioluminescent insects?
  3. Find a gall. What kind of plant is it on? What part of the plant? Collect it, and cut it open. What does it look like inside? What kind of insect do you think this is?
  4. Watch some insects on the surface of a body of water. How do they move? How are they interacting with each other?
  5. Catch some aquatic insects and put them inside a container with water. How do they move? How are they interacting with each other? How are they different from or similar to the semiaquatic insects you observed?
  6. Put an insect inside a Petri dish and under a microscope. Watch it interact with its environment. Describe how it moves. How does it react to disturbance?
  7. Roll a fallen log and describe what you see. What stage of decay is it in? What kinds of insects live there? How are they interacting?
  8. Flip rocks, roll logs, look in acorns, etc. until you find an ant nest. Can you determine the castes? Can you find the queen? What kinds of foods are they gathering? Describe/sketch the architecture of their nest.
  9. Watch insects interact with a flower or inflorescence. What kind of insects do you see? What are they doing. Do it again after dark. Are the insects different?
  10. Find a caterpillar or some other herbivorous insect and watch it eat. Do you see any patterns or strategy?
  11. Grab a fistful of sifted leaf litter, put it in a plastic container, and observe it under a microscope. How many kinds or arthropods do you see, and what are they doing? Fill up a Winkler extractor and see if you can collect even more kinds of arthropods.

Note that for each of these experiences the insect(s) would be collected in the end and the habitat restored as close as possible to its original state, in accordance with the Insect Collectors’ Code.

Edit 1 (26 January 2018): I made some edits to the list (see #2), to incorporate the great suggestion from Paul M. below, in the comments. Thanks!

Edit 2 (26 January 2018): After reading Tom Eisner’s For the Love of Insects I would add a 12th activity …

  1. Find a spider web (orb weaver is probably ideal) and study it. How is it constructed? Are there prey items in it? Can you identify them? Catch some insects and try an experiment: which insects are more likely to escape and why? You could also try experimenting with jumping or wolf spiders in a container, but they might need time to acclimate.
ant pulling a dead bee along the ground
An Aphaenogaster worker pulls a dead Augochlora pura bee in Rock Creek Park, Washington, DC, USA. Photo (CC BY 2.0) by Katja Schulz. Click for source https://flic.kr/p/Mgk52b

Pitcher plant prey

Ha! I just found this list of pitcher plant contents we identified as a class and put together as a draft blog post last September (see previous post for context and additional photos):

  • 2 caterpillars, 2 adult lepidopteran heads (crania)
  • 3–4 spp. of ichneumonid
  • 1 teleasine scelionid
  • lots of flies, including dolichopodids, phorids, and cecidomyiids
  • Psyllidae
  • Thripidae
  • Rhaphidophoridae
  • 3 spp. of ants, including some Camponotus
  • Braconidae: Doryctinae
  • 2 spider spp.
  • Tipulidae
  • Opiliones chelicera
  • Tettigoniidae leg

Alas I never completed the draft, but I do know the plant was Sarracenia purpurea (Sarraceniaceae). I also have a browser open somewhere with a TON of tabs with pitcher plant references. That post lost momentum ages ago, so here are the fragments. Seems like a cool undergrad project here! Maybe next fall I can be a bit more robust about how I sample.

wasp wings and heads floating in ethanol
Parts of ichneumonid wasps, recovered from pitcher plant chyme. Photo (CC BY 2.0) by Andy Deans. Click for source
fly larvae, pupae, and adults in ethanol
Midges (Diptera: Chironomidae), recovered (alive!) from pitcher plant chyme. I have the species name somewhere. Photo (CC BY 2.0) by Andy Deans. Click for source
dead, partly decayed wasp
Teleasine scelionid wasp, recovered from pitcher plant. Photo (CC BY 2.0) by Andy Deans. Click for source

Department of Entomology, in the College of Agricultural Sciences, at Penn State

Visit our Frost Museum facility website for more information

Skip to toolbar