Holometabolous Insects
In this lab you will learn to use spotID characters for identifying selected families of holometabolous insects and you will use the dichotomous key by Bland and Jaques to identify the holometabolous insects in your collection.
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.
Materials
You will need the following materials for this lab:
- Your collected insects
- How To Know The Insects 3rd edition, by R. G. Bland and H. E. Jaques
- Stereoscopic microscope or hand-held magnifier
- Date/Locality labels
- Labeling pen
- Step Block
- Cork observation block
Introduction
During this lab session, we will focus on families of insects (adult stage) in the four largest holometabolous orders: Coleoptera, Lepidoptera, Diptera, and Hymenoptera
Activities
- Assemble your insect specimens, microscope, cork observation block, and labeling equipment.
- Your insects should already be pinned, pointed, or spread according to the protocol you were given in Lab #2. Each specimen should have a Date/Locality label showing where, when, and by whom it was collected (see Collection instructions). 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.
- Identify beetles and weevils – order Coleoptera.
- Use How to Know the Insects by Bland and Jaques as an identification guide. The key to families of Coleoptera begins on page 175.
- Spot ID -- Learn to recognize and distinguish the members of Coleoptera that belong to the following families: Carabidae, Cerambycidae, Chrysomelidae, Coccinellidae, Curculionidae, Elateridae, Gyrinidae, Scarabaeidae, Silphidae, and Staphylinidae.
- Identify moths and butterflies – Order Lepidoptera
- Use How to Know the Insects by Bland and Jaques to identify your insects. The key to families of Lepidoptera begins on page 261.
- Spot ID -- Learn to recognize and distinguish the members of Lepidoptera that belong to the following families: Nymphalidae, Pieridae, Papilionidae, Danaidae, Sphingidae, Saturniidae, Noctuidae, and Arctiidae.
- Identify true flies – Order Diptera
- Use How to Know the Insects by Bland and Jaques as an identification guide. The key to families of Diptera begins on page 318.
- Spot ID -- Learn to recognize and distinguish the members of Lepidoptera that belong to the following families: Tipulidae, Culicidae, Chironomidae, Tabanidae, Asilidae, Syrphidae, Calliphoridae, and Tachinidae.
- Identify insects in the order Hymenoptera
- Use How to Know the Insects by Bland and Jaques as an identification guide. The key to families of Hymenoptera begins on page 363.
- Errors/Corrections -- In couplet #28, the families are reversed. Eumenidae have toothed claws; Vespidae do not have toothed claws.
- Spot ID -- Learn to recognize and distinguish the members of Lepidoptera that belong to the following families: Apidae, Ichneumonidae, Vespidae, Sphecidae, Formicidae, and Halictidae.
Getting help
For help with identification, you can post pictures to the ID Discussion Forum or bring insects to my office. Either way, be sure to note where and when the specimen was collected -- that often helps narrow down the possibilities.
Grading considerations
Your collection will be graded according to the checklist in the “Collection Instructions”. Please note the following points:
All adults in the orders Coleoptera, Lepidoptera, Diptera, and Hymenoptera (that you submit for grading) must be identified to "family". It is not required that adults in other holometabolous orders (e.g. Mecoptera, Neuroptera, Trichoptera, 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 doodlebugs are Mymerleontidae, 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.
If an adult has been preserved in alcohol, be sure to include the word "adult" on its ID label. You will lose two points on your collection grade for each adult in alcohol that does not bear this label.
The specimens you submit for grading should be in relatively good condition. I don’t expect perfection, 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 glue broken appendages back on to the body as long as you do it neatly.
Family ID labels should be located under the date/locality labels and aligned parallel with the long axis of the insect’s body (or long axis of the paper point).
Ecology labels, if present, should be located under the family ID label and down against the pinning surface of your collection box.
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" black ink 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.
