Collecting, Preserving, and Curating Insects. Lab 2, 5 February 2015

Transcription

1 Collecting, Preserving, and Curating Insects Lab 2, 5 February 2015

2 Collecting Two fundamental types: Passive Active Which you use will depend on your goals and/or hypotheses.

3 Forceps Vials Killing jars Boxes Envelopes Aspirators Notebooks Knife Fine brush Plastic bags Hand lens The basics

4 Killing jars Need to kill insects rapidly. No materials that insects can get caught on. We ll use ethyl acetate as our killing agent.

5 Active The Insect Net These can be very different depending on what they are being used for.

6 Active The Insect Net These can be very different depending on what they are being used for.

7 Active Beating sheets Generally used for collecting insects from shrubby vegetation. Umbrellas work well, too.

8 Active Separators & Extractors Generally used for soil or leaf-litter dwelling insects.

9 Active Rearing Great for associating insects with host (plant, animal, or fungus).

10 Passive Flight intercept traps We have three malaise traps available.

11 Can be numerous colors, regardless a4ract both insects that are a4racted to colors and accidental dri7 of insects. Water with a dab of soap to break the surface tension. Water needs to be checked regularly so that pans don t dry out. Pan traps

12 Passive Pitfall and cereal dish traps Great for collecting soil insects. Pitfall traps can be baited or not. Cereal dish traps are always baited.

13 Passive? Light traps Can use multiple spectra. We have blacklights and mercury vapor lights. And a generator to run them.

14 What now?

15 Preserve the insects 70-80% ethanol for most. 100% ethanol for molecular specimens. Glassine envelopes for Lepidoptera, Odonata, other hairy insects.

16 Preserve the insects For butterflies, make sure that the wings are folded backwards (e.g. touching dorsally)

17 Preserve the insects Best to pin immediately. Often not feasible. Store in -20C freezer otherwise. Insects should be kept in sealed zip-lock bags to avoid desiccation. The bags may be put into a Tupperware to prevent damage and confusion with edible items.

18 Preserve the insects Note that you will need to relax your specimens before mounting. Otherwise they will be very, very brittle.

19 Pinning the insects Insects can be direct pinned or pointmounted

20 Where to pin?

21 Where to pin?

22 Spreading Butterflies and Moths Warm water can be injected from the back of the thorax toward the head of the butterfly for a rapid relaxation. Spreading Board Dried Butterfly Warm Water Insect Pins Paper Strips Syringe

23 Basic wing spreading Always be sure the pins are straight when looked at from sides and front. Level the base of the wings with the height of spreading board. Side-view Front-view

24 Where to point? Always on the right side at the thorax. We will use Elmer s glue. Points are made with a special punch. You can bend the card at the tip to make it align with the insect s pleural area.

25 Labeling Very standardized. For direct mounted, always read headto-tail. For point mounted, read with head up.

26 Label data Locality Date Collector Other information Determination label

27 Yellow Pan Trapping We will begin with a very simple and straightforward trapping method. We will set these up today to examine the effect of habitat on insect diversity.

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29 Hypothesis 1. State the hypothesis 2. Set the criteria for a decision 3. Compute the test sta@s@c 4. Make a decision

30 1. the hypothesis What might be the hypothesis that we are in this survey? What is a predic@on borne from this hypothesis? In the context of hypothesis tes@ng, we will assume that the null hypothesis is true. What is a null hypothesis? This is analogous to the presump@on of innocence in a courtroom.

31 The null hypothesis What is our null hypothesis? Usually we are the null hypothesis, however, because we think it is wrong (again, think of the courtroom analogy). What jus/fica/on might we have for the null hypothesis in this context? This can be derived from logic, observa/on, or inference from the literature. We will develop this more next week.

32 Yellow Pan Trapping 4 teams of 4. Each team gets an area. 10 traps per team. You are responsible (as a team) for making sure that the traps do not dry out. Next week we will sort the insects and discuss sta@s@cal analyses. We will then come back in and complete the internal anatomy of the grasshopper