Collecting and Examining Invertebrates
It is first important to recognise that all animals have a right to live in their native habitat.
If you are going to collect fauna it is important to recognise this and that you should have a
good reason to do it. If just curiosity is the criterion, then many invertebrates can be studied
in their natural environment. They can be sketched or photographed, and observations should be
made with their behaviour and how they use their habitats. If you are unable to identify the
animal, then it may be necessary to collect one or a few specimens for identification by specialists.
Never collect more specimens than required as you may be causing the local, even total, extinction
of that particular species
Collecting and preserving invertebrates requires a little equipment which ranges from the very simple to the most intricate and expensive. However there are a few standard items that any collector should have:
For the Walpole Wilderness Invertebrate Fire Research Project we needed to gain an understanding of the biodiversity of different habitats with different fire regimes to help make decisions for management of areas in the future. For this study we needed to collect and preserve our specimens are regular stages (see "The Study" webpage under "The Project" for how our team went about it). We mainly used a systematic pitfall trapping method.
We had sixteen pit traps per site, with each 90mm cup, one third filled with ethylene glycol and opened for ten days. Eight of these traps were dug into the forest floor and the other eight attached to a log, dug into deep tree butt litter or dug inside a hollow butt. Sometimes we used a wire mesh over to trap to keep out heavy forest litter and bigger vertebrates like frogs and lizards. We also direct searched habitats and collected specimens by hand. However we could have also done our collecting by using an insect net, a beating tray, a sieve or use one of the other multitude of methods available to trap these creatures such as baiting or light trapping.
Note that specimens can be kept in captivity for further observation and breeding. It is important to keep moisture levels high to avoid desiccation, to provide adequate and suitable food, and store them with a suitable habitat in a cage or container.
The chemicals involved in killing and preserving specimens can be dangerous and need to be handled with care. Most invertebrate, especially insects and arachnids can be fixed and preserved in 70% ethyl alcohol. This chemical is difficult to obtain due to the necessary stringent laws governing its sale and distribution, so methylated spirits can be used as an alternative. This must be diluted with water or the specimens will become brittle and difficult to work with. Many hard-bodied invertebrates (especiallyinsects) can be killed or anaesthetized in a jar with cottonwool impregnated with ethyl acetate. For our study, after sorting, the specimens were stored in small glass containers containing 70% alcohol or mounted on a insect pin if they are to preserved dry.
"Worms to Wasps" also provides and excellent reference for specific preservation techniques for different invertebrate groups.