Insect Collection

Part of the Biodiversity in the Schoolyard (BitS) unit

Authors: Ryan Hill, Nicole VanderSal, and Alison Purcell

Overview: In this lesson students will learn how to use several types of insect sampling and collection equipment. Students will work in groups to collect insects in different areas of their schoolyard.

Lesson Concepts:

  • Sampling insects is one way to estimate the abundance and number of species (species richness) of insects of an area.

  • There are several ways to collect insects and you should select your method based on the type of habitat you are sampling.

  • Insect composition can differ between different habitat types.

Grade Span: 9–12

Materials:

  • Quadrats: 1 m2 (6; at least 2 per group)

  • Beating sheets (4; at least 1 per group)

  • Sweep nets (4; at least 1 per group)

  • Aerial nets (10; at least 2 per group)

  • Plastic vials (enough for 4-8 vials per student)

  • Plastic "ziplock" gallon bags

  • Glassine envelopes or triangles for butterflies and dragonflies (wax paper would suffice)

  • Soft forceps

  • Data labels with student name, date

  • Sharpie markers for labelling plastic bags

Advance Preparation:

  1. Visit the three different areas to be sampled prior to the field trip.

  2. Gather all required equipment.

  3. Prepare labels: There are two choices for preparing the labels:

    1. Prepare and cut out ~8 labels per student with student name and date to be placed in each of the student's vials. The vials are then placed in a separate plastic bag for each collection method (quadrat, beat sheet, etc). Each bag has collecting method, date and location clearly written on outside.

    2. Prepare and cut out ~8 labels with a space for student name, date, location, and sampling method to be placed in each of the student's vials. Make sure the students keep specimens from each sampling method separate.

Time: 1 hour

Grouping: Break the class into 3 groups (each group to be lead by an instructor).

Teacher Background: (optional)
Most arthropods may be collected in empty vials, vials filled with ethanol or kill jars. However, Lepidoptera (moths and butterflies) should be kept separate in glassine envelopes to reduce wing scale loss, and Odonata (dragonflies and damselflies) can also be placed in envelopes and then later curated in plastic sleeves to save space. In the procedure outlined here, we prefer collecting in empty vials and then placing the specimens in the freezer for several days before pinning. This method avoids using ethanol and other chemicals used in kill jars, and does a decent job of producing nice specimens.

Teaching Tips:
Record keeping/Standardization: In an effort to standardize for comparison between areas/schools, instructors should record data for each group: number of students in group, time sampled using each method, weather conditions, name of area sampled (could be quantified later). In the interest of maximizing collecting time we suggest group leaders write this down. However, depending on your group's maturity it may work to have a record keeper. Also we suggest asking your group for predictions about which method will be most effective for collecting to refer back to in reflection.

Vocabulary: quadrat, sample, insect, arthropod, arachnid, species richness, species abundance

Procedure:

  1. Introduction (10 minutes)
    Break class into three groups and assign them to a particular sampling area. Explain to students that they will be using three different techniques to collect insects. Divide equipment equally so that each group gets at least 1 of every type of sampling equipment. Each group then goes to their sampling area.

  2. Insect Collecting: Each group will rotate through each collecting technique.

    1. Quadrats (15 minutes): First, explain that quadrats are generally used to randomly sample insect diversity on the ground. Demonstrate randomly throwing the quadrat and collecting insects within the quadrat. Divide students into groups with one quadrat per group. Have students randomly throw their quadrat into the sampling area, then collect all ground insects within this quadrat. Have them spend at least five minutes searching a space and then have them repeat it a second time. Students can use their fingers, forceps, or vials to pick up the insects. Each student must put a label in their vial once the insects are collected. All vials from the quadrat sample should be placed in a ziplock and labeled "Quadrat," with location and date. This will keep these vials separate from those collected from other methods.
      *Note: If there is one species of insect that is very abundant within a quadrat, the students do not need to collect all individuals, but they should collect a minimum of five specimens of each species if possible to compare variation within species.

    2. Beating sheet, aerial nets, and sweep nets (15 minutes): Demonstrate using each of these sampling methods and then break students into pairs to collect. Instructor should record how many students are using each type of equipment. Students may switch equipment with another pair once they have sampled for a while if they want to experience different methods. Be sure each student places a label in the vial with each of their samples keeping aerial, beat sheet and sweep samples in separate vials. Again, place the vials from the different collection methods into ziplock bags with the name of the collection method ("Beat sheet," "Aerial net," "Sweep net"), date and location information written on the bag.

  3. Wrap-up and Clean-up (10 minutes)
    Have students return to the classroom. Collect all sampling equipment and specimens. Keep specimens separated by group and sampling method. If time, have students share experiences in the classroom.

    All insect specimens need to be put in the freezer as soon as possible after this activity. Snap cap vials and ziplock bags should be sufficient to maintain them for up to 1-2 weeks before curation.

Extensions: Follow this activity with insect curation the next week.

Reflections: Refer back to student's predictions and ask:
What method seemed to sample the highest number of insects?
What method seemed to sample the most species of insects?

 
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