Lab 12. Identification: Holometabolous Insects (Part 2)

In this lab you will learn to use Spot ID characters, and keys for identifying adult insects from your collection to family level in two of the four largest holometabolous orders (Diptera, Hymenoptera).  

Objectives

The main objectives of this lab are to help you:

  1. learn to identify selected families of holometabolous insects based on key characters
  2. identify (to family) the holometabolous insects that you will submit with your insect collection.

Activities

1. Assemble your insect specimens, microscope, cork observation block, and labeling equipment.

Your insects should already be pinned, pointed, or spread according to the “Insect Collection Instructions” on the course website.   Each specimen should have a temporary label, hand-written in pencil only with the following information: 1) collection date; 2) collector name; 3) collection location.   Handle your specimens with great care.  Once they are dry, they become very brittle.  Using the cork observation block to position your specimens for viewing under the microscope helps reduce accidental breakage.

2. Lab Exercise – ID 5 Specimens to Family Level From  the Orders Diptera and Hymenoptera.

This exercise will be graded in lab.  For details of this lab exercise, please go to the ENT 425 Moodle site. DE Students, please go to the ENT 425 Moodle site to see how to get graded.

PART A: Identify Specimens in Order Diptera.  Use the “KWIK-KEY” on the course Moodle site (Week 12) to identify your Coleoptera specimens to family level.  Write the family name on your temporary label.  Remember, each specimen must eventually have permanent labels from the Insect_Collection_Labels form with all the information described in the label instructions.

PART B: Identify Specimens in Order Hymenoptera. Use the resources listed on the course Moodle site (Week 12) to identify your Coleoptera specimens to family level.  Write the family name on your temporary label.  Remember, each specimen must eventually have permanent labels from the Insect_Collection_Labels form with all the information described in the label instructions.

3. Getting help

Take advantage of both lab periods and office hours.  Outside of these times, you can make arrangements with the instructor or TA for additional help.  Beyond this, you can post pictures to the “What’s This” discussion board (top of Moodle page).  Either way, be sure to note where and when the specimen was collected — that often helps narrow down the possibilities.

4. Grading considerations

1.  Your collection will be graded using the form in the “Grading” tab of the “Insect Collection Instructions”.

2.  All adults in the orders Odonata, Orthoptera, and Hemiptera (that you submit for grading) must be identified to “family”.  It is not required that adults in other hemimetabolous orders (e.g. Plecoptera, Dermaptera, Psocodea, etc.) be identified to family level, but you can earn family credit for any specimens that are labeled with the correct family name.  In some cases, family identity is easy to determine (all praying mantids are Mantidae, for example).  In other cases, the family may be difficult to determine without high magnification or special mounting techniques.  Don’t waste a lot of time on these insects – just give the order name.

3.  The specimens you submit for grading should be in relatively good condition.  Perfection isn’t expected, but all insects should have the head, thorax, and abdomen intact.  A few missing or broken appendages are acceptable as long as the corresponding part on the opposite side of the body is still present (i.e. one of everything!).  You may use clear nail polish to glue broken appendages back on to the body as long as you do it neatly.

4.  You can begin putting permanent labels on your specimens if you wish to.  To get the form for making permanent labels, click the link in the last line of the Insect Collection Instructions page, entitled “Use only the Insect_Collection_Labels form to make your permanent labels.”  All labels should be kept exactly the same size and format as they appear on the above form.  Remember, permanent and temporary labels should be aligned parallel with the long axis of the insect’s body for pinned specimens, or the long axis of the paper point for pointed specimens.

5.  Although ecological category labels are optional, this part of the collection is worth one third of the collection grade!.  Do not neglect this part of the collection.

6.  You will lose points on your collection grade for any of the following mistakes:

  • Date/locality label missing or formatted incorrectly.  See “Collection Instructions”.
  • ID label missing or incorrect.  See “Collection Instructions”.
  • More than one ecology label.  For specimens that fulfill more than one ecological category, put all key words on a single label.
  • Failure to use “permanent” ink (i.e. laser printer) for labels.
  • Immature specimen is pinned without “immature” appearing on the ID label.
  • Adult specimen is in alcohol without “adult” appearing on the ID label.
  • See the Insect Collection Grading Form for more details.

5. Materials

You will need the following materials for this lab:

  • Your collected insects
  • Preserving Gear
  • Smartphone or computer to access the “KWIK-KEYs” on the course Moodle site (Week 12)
  • Stereoscopic microscope or hand-held magnifier (provided in lab)
  • Temporary labels (hand-written in pencil only on small pieces of paper)