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

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2 Responses to Observing insect natural history

  1. Paul M. says:

    Along the lines of your first one: a night walk, and take the chance to turn off your headlamp for 10 mins. to get your eyes adjusted (probably want to stop walking or just go slow). Look out for bioluminescent fireflies, and their larvae. Of course, especially cool in Madera Canyon (AZ), w/ all their phengodids, Sierra Nevada (CA) or the tropics but there are neat glowing things to see in the east too!

  2. Andy Deans says:

    Thanks Paul! I had that exact experience on my last field trip for this class. I walked in the dark for 15 minutes and found a larval (or larviform?) lampyrid. I should’ve remembered that. Thanks!

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