ARTHROPODS
We advocate the use of one protocol

PROTOCOL 5
“COBRA modified” (adapted from Cardoso 2009)
Taxa
Spiders and beetles
Experimental design
Sampling the 50m × 50m plots
Frequency
The complete protocol should be applied for an initial inventory. The monitoring protocol as described in the main text is adequate for sampling every five or ten years.

The COBRA protocol was originally developed as a semi quantitative protocol for the analysis of Mediterranean spiders (Cardoso 2009), but recently an adaptation was developed within the NETBIOME ISLANDBIODIV and MACDIV projects for a broader analysis of spider and beetle diversity (see also Emerson et al. 2017).

Sampling Effort
Sampling Effort:: In total the sampling protocol requires 16 hours of field searching and collecting, approximately three hours for the placement of pitfall traps, approximately 5 hours for the placement of pitfall traps, approximately 5 hours for the removal of pitfall traps and one hour to collect leaf litter, which means a total of 24 person hours per plot. Usually four researchers are needed per plot.

Collectors should use a stopwatch to control the time that is spent collecting, and to be able to stop the counter when occupied with other activities (e.g. photography, maintenance of tools, eating, etc.; during one hour of collecting, 10 to 20 minutes can easily be dedicated to such activities).

Protocol 5A -- The complete COBRA protocol for inventorying

Nocturnal active aerial searching (AAS) – This method consists of collecting all spiders and beetles found above knee-level by hand, forceps, pooter or brush and immediately transferring them into vials containing alcohol. All the time spent in searching for spiders and beetles is to be accounted for. Sampling lasts four hours (one hour per sample).

MATERIALS: Forceps, pooters or brush and vials.

Diurnal active aerial searching under bark, lichens and bryophytes (ABS) – This method consists of collecting mostly beetles, but also spiders, found above ground level under bark and under lichens and trunks using a small hoe to remove bark and lichens. The use of forceps, pooter or brush can also be helpful. Animals are immediately transferred into vials containing alcohol. All the time spent in searching for spiders and beetles is to be accounted for. A beating tray should be used to accommodate the debris that will be searched for. Searching lasts two hours.

MATERIALS: Small hoe, forceps, pooter or brush, beating tray and vials.

Diurnal active aerial searching in decaying trunks, dead wood on the ground, and under stones (GWS) – Similar to the aerial method, but directed towards beetles and spiders found below knee-level, including species in hidden sites such as below stones or inside hollow trunks, and in dead wood. Use the small hoe to break the wood. A one m2 white cloth sheet should be used to accommodate the debris on the ground and search for animals falling from the wood. Animals are immediately placed into vials containing alcohol. Searching lasts two hours.

MATERIALS: Small hoe, forceps, pooter or brush, white cloth sheet and vials.

Foliage Beating (FB) – A 110 cm × 80 cm white fabric with a frame should be used as a drop-cloth (beating tray) and a wooden pole of at least 1.5 m used to beat tree branches, as high as possible. The effective time includes all the time spent in the activity, namely beating, searching for fallen spiders and beetles on the cloth and transferring them into vials. Two samples during the day (FBD) and two samples during the night (FBN) are to be collected. Sample lasts two hours during the day and two hours during the night.

MATERIALS: Beating tray, forceps, pooter or brush and vials.

Foliage sweeping (FS) – A round sweep net with an opening diameter of 46 cm is used to sweep bushes and tall herbs. All time spent sweeping or searching for dislodged spiders and beetles is accounted for. Two samples during the day (FSD) and two samples during the night (FSN) are to be collected. Sample lasts two hours during the day and two hours during the night.

MATERIALS: Sweep net with an opening diameter of 46 cm, pooter or brush and vials.

Pitfall (PIT) – Forty-eight pitfall traps (8 cm wide at the top, and approximately 12 cm deep - European standard 33cl plastic cups) are placed immediately outside the perimeter of each sampling plot, 12 along each edge of the square plot, spaced equidistantly. Traps are filled with 3 – 4 cm of 100% propylene glycol and left in the field for 14 days. Traps are protected from predation, inundation with rain water, and unwanted vertebrate capture (i.e. reptiles) using plastic plates sitting on stilts 2 cm above the ground surface. A group of four contiguous traps are counted as one sample, summing to 12 samples per plot. As the traps are sometimes fragile, two cups could be used per trap, one placed inside the other.

MATERIALS: Small hoe; standard 33 cl plastic cups, 8 cm wide at the top and 12 cm high; plastic picnic plates and pieces of wire.

SAMPLING EFFORT
SAMPLING EFFORT: One day per plot with two researchers.

Protocol 5B -- The COBRA protocol for monitoring

Nocturnal active aerial searching (AAS) – This method consists of collecting all spiders and beetles found above knee-level by hand, forceps, pooter or brush and immediately transferring them into vials containing alcohol. All the time spent searching is to be accounted for. Sampling lasts four hours (one hour per sample).

MATERIALS: Forceps, pooters or brush and vials.

Foliage Beating (FB) – A 110 cm × 80 cm white fabric with a frame should be used as a drop-cloth (beating tray) and a wooden pole of at least 1.5 m used to beat tree branches, as high as possible. The effective time includes all the time spent in the activity, namely beating, searching for fallen spiders and beetles on the cloth and transferring them into vials. Two samples during the day (FBD) or two samples during the night (FBN). Sampling lasts two hours (one hour per sample).

MATERIALS: Beating tray, forceps, pooter or brush and vials.

SAMPLING EFFORT
SAMPLING EFFORT: One evening/night per plot with two researchers.

References
Cardoso P (2009) Standardization and optimization of arthropod inventories – the case of Iberian spiders. Biodivers Conserv 18:3949-3962. doi:10.1007/s10531-009-9690-7
Emerson BC, Casquet J, López H, Cardoso P, Borges PAV, Mollare, N et al. (2017) A combined field survey and molecular identification protocol for comparing forest arthropod biodiversity across spatial scales. Mol Ecol Resour 17:649-707. doi:10.1111/1755-0998.12617

If you upload the PDF, I’ll apply the exact same cleanup to all pages (remove line numbers, fix broken wraps, preserve headings/bullets, and keep content unchanged).