for Arthropod Pitfall Sample Analysis
minimum of 9 pitfall traps should be established at each
locality (not each web). Pitfall traps should be left open continuously
samples should be collected during the same period as the monthly
sampling. The entire contents of the pitfall trap should be rinsed into
with a label (100 % cotton rag paper and permanent ink) containing the
pitfall number, and date.
back from the field, the contents of each jar should be rinsed and all
for CSU, MT, and Yavapai) Based on the attached list of likely food
arthropods for Peromyscus, separate each pitfall sample into
two groups: (a)
Food Source Arthropods and (b)
Non Food Source Arthropods.
Each of these groups is to be vialed and labeled separately in
Wheaton, snap-cap (or similar) vials.
For Food Source Arthropods and Non Food Source Arthropods separate
specimens into categories by order as listed on the attached Arthropod
Sheet. Taxa not listed on the data sheet should be listed under
and weigh the specimens in each taxon and record values in the
location on the data sheet and in an MS Excel spreadsheet.
any orders that do not contain taxa as 0 in the spreadsheet instead
arthropods from all orders should be lumped in one group and not
included in the
totals, as pitfalls cannot accurately sample flying species. However,
desirable to know when there is an influx of some species (e.g., moths,
cicadas), so count, weigh, and note dominant species in sample.
for each order and the pitfall totals need to be taken at equal
The evaporation rate is quite high for 70% ETOH and weights will
should be kept wet until just prior to weighing. Total weights should
obtained by combining all samples and then reweighing, as opposed to
adding the previous totals for each order. This will incorporate the
those orders that are <.01 g and did not register on the scale. The
use of a
drying oven to obtain dry weights would be ideal but would add time and
complexity to the procedure. Since we are interested in the change
wet weights are sufficient as long as they are done consistently.
samples should then be returned to their labeled jars in 70% ETOH and
as voucher specimens for future use or reference. As a final step, an
voucher collection should be prepared, consisting of one member of each
with an identification label.
Food Source Arthropods
- Amblypygi (Tailless Whipscorpions)
- Araneae (Spiders)
- Chilopoda (Centipedes)
- Coleoptera (Beetles)
- Dermaptera (Earwigs)
- Dictyoptera (Cockroaches and Mantids)
- Diplopoda (Millipedes)
- Diplura (Diplurans)
- Hemiptera (True Bugs)
- Isopoda (Sowbugs)
excluding males (Termites)
- Opiliones (Harvestmen)
- Orthoptera (Grasshoppers, Crickets, Katydids)
- Phasmida (Walking Sticks)
- Solpugida (Windscorpions)
Non Food Source Arthropods and
those not accurately sampled by pitfalls.
- Collembola (Springtails)
- Diptera (Flies)
adults (Cicadas/Leaf Hoppers)
- Hymenoptera (Ants, Bees, Wasps)
adults (Butterflies and Moths)
- Neuroptera (Lacewings, Antlions)
- Any taxa
which are 5mm or less in body length.