ADJUNCT SAMPLING PROTOCOLS AND PUBLIC PARTNERSHIPS

A.T. Finnamore

Provincial Museum of Alberta, Edmonton, Alberta, Canada T5N 0M6

Introduction

Public involvement in scientific undertakings is unfortunately an uncommon occurrence. Public exposure to science is usually highly filtered, often condescending, and gained through the media, museums and the school systems. Rarely is exposure gained directly from scientists or by participation in research projects. The signing of the United Nations Convention On Biological Diversity in 1992 was a watershed in recognition of the global biodiversity crisis confronting human society. Now, more than at any previous time in history, human society needs expertise in "whole organism" biodiversity to explore the extent of the resource, and manage for use by future generations that which remains. Among the very best methods for introducing the public (especially the young public) to biodiversity (and science in general) is through direct participation and recognition for contribution to research projects.

Volunteer Groups And Appropriate Protocols For Monitoring Arthropods

Their small size and difficulty in species identification render arthropods generally less suitable as subjects for public involvement than other organisms, like vascular plants or vertebrates. This is compounded by the rigorous sampling methodology, infrastructure, and equipment necessary for processing specimens and producing data of value for comparison of species assemblages. Nonetheless, butterfly counts have become fashionable, indicating that many difficulties associated with arthropods can be overcome when larger species are the focus and identification guides are available.

Biodiversity, considered at the species level, is a function of both species richness (number of species) and abundance (number of individuals per species). All of the biotic protocols presented in previous sections of this report will provide some qualitative measure (species richness) at a given site, and if applied in a consistent manner can provide data suitable for comparative analysis. The protocols presented previously will also provide quantitative measures (abundance) in the form of relative trapability.

Several protocols were excluded from the foregoing treatment (hand collecting, sweep netting, light traps) because of difficulty in applying standards or inability to reduce collector subjectivity. However, these protocols can be used to augment and serve as a check on richness measures (lists of species) obtained by the more rigorous protocols presented previously. Data from these protocols can, over time, be used to provide evidence of increasing (species range extensions) and decreasing species richness (species range reductions). They also have the advantages of being cheap and easy to apply. For instance they do not require an intensive field installation effort, are not appropriate for continuous sampling and so do not require periodic servicing.

Hand Collecting: Among the most traditional methods for arthropod sampling, hand collecting remains the technique of choice for many professionals. Vegetation, substrate, or any habitat of interest is visually examined for arthropods. For example rocks and logs can be turned over (and often subsequently replaced to retain the microhabitat for future use) and any arthropods captured for identification. Species richness monitoring requires species level names. A collection of mounted, labelled, identified voucher specimens should be established to provide proof of an observation at each locality. Many large insects can be captured, identified by comparison with the voucher specimens and released. Specimens representing new records can be killed in water with a few drops of soap added as a surfactant (breaks surface tension). Specimens can then be mounted (Martin 1977), labelled (see Masner, this volume), identified and added to the voucher collection.

Sweep Sampling: Sweeping is one of the most effective methods for quickly capturing large quantities of insects in vegetation. A standard or reinforced insect net (for construction see Martin 1977) is employed in a sweeping motion on vegetation to dislodge the arthropods. Arthropod samples collected with this technique are affected by time of day, moisture, temperature, mesh size of the net, and subjectivity of the collector. In the latter case different collectors focus their collecting efforts on different aspects of the vegetation. The sweeping motion concentrates arthropods and debris in the apex of the net. Arthropods can be separated from debris using a separation bag (Masner and Gibson 1979). Separation bags use the positive response to light exhibited by many arthropods to separate them from debris. Samples can then be processed as in the section on hand collecting above. Sweep nets are inexpensive and commercially available.

Light Traps: Many nocturnal insects are attracted to artificial sources of light. Light trapping is one of the most effective means of collecting large numbers of nocturnal insects. A number of light traps are commercially available but almost any light will work. Ultra violet (mercury vapour lamps) is the most effective. Fixtures and filtered ultra violet tubes are available at larger commercial hardware outlets. The light should be placed in front of a vertical white sheet and for best results operated on a warm moonless night away from competing light sources. Insects attracted to the light will land on the sheet where they can be collected. In many field conditions batteries or generators are used as a source of power.

Conclusion

The most appropriate level for public participation in biodiversity monitoring programs for arthropods in most instances may be through use of sampling protocols to assess species richness. Groups that can be readily identified to species level like butterflies, large moths, large beetles, grasshoppers, dragonflies and damselflies should be selected for monitoring.

Reference

Martin, J.E.H. 1977. Collecting, preparing, and preserving insects, mites, and spiders. The insects and arachnids of Canada Part 1. Research Branch Canada Department of Agriculture, Publication 1643. 182 pp.

Masner, L. and G.A.P. Gibson. 1979. The separation bag - a new device to aid in collecting insects. The Canadian Entomologist 111:1197-1198.