DOI: 10.5061/dryad.v15dv41w1
title: Spiders sampled during student excursions at Bankfontein farm

description: As part of an undergraduate Entomology module, field excursions were
 undertaken to a mixed livestock farm in central South Africa, during
 March-April 2015, 2016 and 2018–2020. The aim was for groups to determine
 and compare terrestrial arthropod biodiversity in three strata of three
 contrasting biotopes, with particular emphasis on insects. To determine
 the contributions such excursions make to documenting biodiversity of a
 non-target taxon, the spider (Arachnida: Araneae) data generated by
 students was compared with the local species richness (LSR) for the area.
 The LSR for the farm Bankfontein included a total of 242 species,
 representing 40 families. Over the five years, student groups sampled a
 total of 158 spider species, representing 65.3 % of the LSR. The number of
 species sampled per year ranged between 57 and 94 for undergraduate
 students (1–3 groups), and was 119 species for the final year of the study
 carried out by the author and two post-graduate students (2 groups), which
 could be attributed to collector experience and modification of the
 sorting process for beat sampling, particularly. This study emphasises the
 importance of utilizing students as a valuable resource to generate
 biodiversity data, particularly where financial and human resources may be
 limited.
description: Each student group was
 required to implement a standardised sampling protocol in each of the
 three biotopes. Considering the paucity and low growth of grasses in the
 Nama Karoo veld, no sweep-net sampling was undertaken. This contrasts with
 the regular practical assignments, which rely exclusively on sweep-net
 sampling. Three methods were employed in each biotope by each group to
 sample arthropods: 1) 10 pitfall traps (6 cm
 diameter 250 ml bottles) were set out 5 m apart in a line transect.
 Ethanediol (50 ml) was added to each pitfall trap as a preservative, with
 traps kept open for 4 days (96 hours) before being removed. Where multiple
 student groups sampled in a single year, trapping transects were separated
 by at least 10 m to minimise interference. Arthropods were sorted from the
 collected material in white plastic trays and preserved in 70 % ethanol in
 separate vials for each sample; 2) 10 leaf litter samples were
 taken by filling 5 l plastic freezer bags with litter from beneath woody
 plants. The collected material was sifted over a large white sheet using a
 round steel sieve with a diameter of 45 cm, height of 10 cm and mesh
 spacing of 8 mm. Specimens sampled by litter sifting were collected with
 forceps or clean glass vials and put into separate vials containing 70 %
 ethanol for each sample. For this method, either the author or one senior
 post-graduate student assisted each student group with collecting
 specimens from the sheet; and   3) 10 beating samples were taken
 by striking the branches of woody foliage 50 times over a standard
 sweep-net with a diameter of 40 cm. Each of the 50 beat units comprised
 striking a single branch at the same point three times before moving onto
 the next unit. Once 50 units had been completed, the sampled material was
 transferred to a 5 l plastic freezer bag until sorting in the laboratory.
 Beat samples were euthanised using toilet paper doused in ethyl acetate,
 which was added to each bag on return to the field laboratory. This was to
 ensure that flying insects could not escape during sorting. The material
 was then emptied into large white plastic trays, and the arthropods
 removed using forceps and transferred to vials containing 70 %
 ethanol. The
 number of samples per habitat and method was determined by the number of
 student groups on each trip: 30 (2015), 20 (2016), 10 (2018), 30 (2019)
 and 20 (2020). In all of the years, students were responsible for all
 sampling and processing of material, except for 2020, when the University
 of the Free State closed in the week prior to the proposed excursion due
 to the COVID-19 pandemic. The author and two post-graduate students (one
 Ph.D and one M.Sc level) consequently undertook the sampling before
 national government imposed a national lockdown on 27 March 2020, and
 executed collecting for the two student groups that would have undertaken
 the excursion.
description: This dataset is a summary of five years' sampling using
 three methods (beating B, litter sifting L and pitfall trapping P) in
 three biotopes (Nama Karoo veld N, riparian woodland R and hillside
 grassland H) in central South Africa. The raw data can be requested from
 Charles Haddad (haddadcr@ufs.ac.za).