Pitfall trap designs to maximize invertebrate captures and minimize captures of nontarget vertebrates

2005 ◽  
Vol 137 (2) ◽  
pp. 233-250 ◽  
Author(s):  
J.L. Pearce ◽  
D. Schuurman ◽  
K.N. Barber ◽  
M. Larrivée ◽  
L.A. Venier ◽  
...  

AbstractPitfall traps containing a preservative have become the standard method of sampling for epigeal invertebrates such as carabid beetles and cursorial spiders. However, they often result in high levels of mortality for small mammals and amphibians. We compared the carabid, spider, and vertebrate captures within five pitfall trap types (conventional trap, funnel trap, shallow trap, Nordlander trap, and the ramp trap) to determine the trap type that would reduce vertebrate incidental catch without compromising the capture of invertebrates. We also examined the effect of a mesh screen over pitfall traps on carabid beetle and vertebrate catches. All modifications to the conventional trap design resulted in a reduction in both small mammal and amphibian captures. The shallow pitfall trap and the funnel trap captured a carabid beetle and spider fauna similar to that captured by the conventional trap. The species compositions of the ramp trap and the Nordlander trap were different from those of the other trap types, but these traps were more efficient, capturing more species per individual captured. The ramp trap appeared to be the method of choice for sampling epigeal spiders. Thus, the choice among trap designs for invertebrates depends on the objectives of the study. However, an alternative to the conventional trap design should always be considered to reduce small mammal mortality.

1995 ◽  
Vol 6 (2-3) ◽  
pp. 65-77 ◽  
Author(s):  
Johan Andersen

A comparison was made betweeen the "open" pitfall trap method and quadrat sample method in microhabitats on river banks. The latter method was found to give reliable estimates of the absolute abundance of carabid beetle species. In pitfall traps individuals of the carabid beetle Bembidion schuppelii were over-represented in a sub-optimal microhabitat compared with in optimal ones. The niche-overlap between this species and B. bipunctatum was 0.19 in quadrat samples and 0.59 in pitfall traps. There was no correlation between the relative abundance of individuals of species in quadrat samples and in pitfall traps. Individuals of larger carabid species were highly over-represented compared to smaller ones in pitfall traps, an effect that was independent of diurnal rhythm and life cycle category. Biomass of larger carabid species was also overestimated in pitfall traps compared to that of smaller ones. Imagines were more efficiently captured in pitfall traps than larvae. Pitfall traps had a higher number of species than quadrat samples in all investigated sites. In four of five cases the Shannon-Wiener index gave higher species diversity in pitfall traps than in quadrat samples. It is concluded that the "open" pitfall trap method is inappropriate to study dominance ratio, the ecological role of species and perhaps the species diversity within communities. The general insight into the community structure of carabid beetles may therefore be very biased.


2020 ◽  
Author(s):  
Antoine Gardarin ◽  
Muriel Valantin-Morison

Abstract In arable agroecosystems, arthropod communities often have a reduced abundance and diversity, which represents a challenge for sampling techniques needed to detect small differences among these simplified communities. We evaluated the suitability of pitfall traps for comparing the effects of cropping systems on arthropod communities. In a field experiment, we compared the effects of two pitfall trap diameters, the type of preserving fluid and the sampling effort on three metrics (activity density, taxonomic richness, and community weighted mean [CWM] of body size) for carabids and spiders. Trap size affected the observed composition of communities, with large traps yielding a higher proportion of spiders, and a higher richness and CWM body size for both taxa. The type of preserving fluid had a weaker effect. Simulations with various sampling efforts showed that only very different communities could be distinguished with less than 10 traps per field or less than 30 field replicates. Fewer traps were required to find differences between cropping systems for body size than for other metrics. Carabid activity density and body size, and spider genus richness, were the variables better distinguishing between cropping systems with the smallest sampling effort. A high sampling effort was required for comparing activity density and richness across cropping systems. Selection of the most appropriate trap design, metrics, and crops are the main factors for optimizing the trade-off between sampling effort and the ability to detect arthropod community responses to habitat management.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5078 ◽  
Author(s):  
Fabian A. Boetzl ◽  
Elena Ries ◽  
Gudrun Schneider ◽  
Jochen Krauss

Background Pitfall traps are commonly used to assess ground dwelling arthropod communities. The effects of different pitfall trap designs on the trapping outcome are poorly investigated however they might affect conclusions drawn from pitfall trap data greatly. Methods We tested four pitfall trap types which have been used in previous studies for their effectiveness: a simple type, a faster exchangeable type with an extended plastic rim plate and two types with guidance barriers (V- and X-shaped). About 20 traps were active for 10 weeks and emptied biweekly resulting in 100 trap samples. Results Pitfall traps with guidance barriers were up to five times more effective than simple pitfall traps and trap samples resulted in more similar assemblage approximations. Pitfall traps with extended plastic rim plates did not only perform poorly but also resulted in distinct carabid assemblages with less individuals of small species and a larger variation. Discussion Due to the obvious trait filtering and resulting altered assemblages, we suggest not to use pitfall traps with extended plastic rim plates. In comprehensive biodiversity inventories, a smaller number of pitfall traps with guidance barriers and a larger number of spatial replicates is of advantage, while due to comparability reasons, the use of simple pitfall traps will be recommended in most other cases.


1991 ◽  
Vol 123 (4) ◽  
pp. 851-859 ◽  
Author(s):  
J. Martel ◽  
Y. Mauffette ◽  
S. Tousignant

AbstractThe impact of canopy dieback on the activity and diversity of epigeal Carabidae was studied during the summers of 1987 and 1988 in 18 maple stands in southeastern Québec, using pitfall traps. A canopy thinning index (CTI) based on severity and incidence of dieback, and on tree basal area was calculated for each of the 72 stations sampled. An analysis of variance shows that canopy dieback had a significant effect on carabid beetle activity in 1988. The CTI was negatively correlated with the carabid species richness and diversity in 1988. The number of individuals caught per station was negatively correlated with the CTI for all species combined, except for the dominant Pterostichus coracinus Newm. in 1988. These results indicate a negative response of carabid beetles to canopy dieback in 1988; the climate may have tempered the effects of dieback in 1987.


2007 ◽  
Vol 28 (3) ◽  
pp. 321-328 ◽  
Author(s):  
Bryan Maritz ◽  
Gavin Masterson ◽  
Darian Mackay ◽  
Graham Alexander

Abstract Funnel and pitfall traps that are set in association with drift fences are powerful tools for field herpetologists. Innovations in trapping techniques continue to improve capture rates, portability and affordability of trap materials, and to decrease construction and installation time. In this paper we test a new design for funnel traps and test the effect of pitfall trap size on trap success. Our new funnel trap design was significantly easier and quicker to construct, but captured fewer specimens than the traditional design. There was no significant difference in the capture rates of the two sizes of pitfall trap that we tested. This finding was confirmed by a second, more extensive field survey. The implications of trap efficacy on ecological investigations are discussed.


2003 ◽  
Vol 14 (1) ◽  
Author(s):  
Matti Koivula ◽  
Johan Kotze ◽  
Laura Hiisivuori ◽  
Hannu Rita

Apart from experimental design, the selection of pitfall trap size, collecting fluid and habitat type sampled may also influence the capture efficiency of the method. We combined three field studies from two very different geographic areas, in which the efficiency of pitfall traps, using carabid beetles (Coleoptera: Carabidae), is evaluated. First, we showed that ethylene-glycol is a more efficient collecting fluid compared to commercial anti-freeze, paraffin and salt water in collecting beetles in a forest patch in South Africa. Second, we showed that larger traps (90 mm mouth diameter) are more efficient in collecting carabids than small traps (65 mm) in a meadow in Finland. We also showed that for these large traps, commercial vinegar was a better collecting fluid than propylene-glycol, but that for small traps, propylene-glycol was superior to vinegar in collecting carabids. Finally, we showed that the trappability of Pterostichus oblongopunctatus and Carabus hortensis differed in enclosures placed into two different habitat types (a forest and a clear-cut in Finland), while trappability did not differ significantly for two other species (Calathus micropterus and Pterostichus niger) in these habitat types. However, for the two Pterostichus species studied, the catches in traps placed in the centre of the enclosures were slightly higher in the clear-cut, compared to the forest, and catches were higher in enclosures with rich field-layer vegetation, compared to enclosures with poor vegetation. The three studies re-emphasise the uncertainties of using pitfall traps in ecological studies. However, with careful planning and standardisation to help avoid erroneous interpretations, pitfall trapping is an invaluable method for the field ecologist.


2020 ◽  
Vol 12 (24) ◽  
pp. 10673
Author(s):  
Axel Schwerk ◽  
Marzena Wińska-Krysiak ◽  
Arkadiusz Przybysz ◽  
Ewa Zaraś-Januszkiewicz ◽  
Piotr Sikorski

Urban wasteland is of special interest to city planners. However, to integrate such areas into city space management with consideration of nature conservation aspects, a sound assessment of their ecological potential is necessary. The aim of this paper was to analyze whether carabid beetle assemblages of the wastelands are affected by soil parameters, particularly trace element contamination. Therefore, we studied the carabid fauna in relation to selected soil parameters on 56 sampling plots situated in 24 wastelands located in the city of Warsaw (Poland). The results have confirmed our assumptions that the number of species, as well as the number of individual carabid beetles, are negatively affected by an increasing amount of pollutants in the soil. Particularly, the trace elements Pb, Cu, and Cd showed a significantly negative impact. The results are of value when it comes to the use of urban wastelands in the context of sustainable city development. Future use of urban wastelands will be faced with trade-offs between the use for public interests (e.g., housing space) and ecological interests. Phytoremediation and entomoremediation may be included in decontamination measures. The results of studies, such as the one conducted by us, may help to select the respective wastelands for certain purposes.


2019 ◽  
Vol 49 ◽  
Author(s):  
Lisa A. Berndt ◽  
Eckehard G. Brockerhoff

Background: Land cover changes during the recent history of New Zealand have had a major impact on its largely endemic and iconic biodiversity. As in many other countries, large areas of native forest have been replaced by other land cover and are now in exotic pasture grassland or plantation forest. Ground beetles (Carabidae) are often used as ecological indicators, they provide ecosystem services such as pest control, and some species are endangered. However, few studies in New Zealand have assessed the habitat value for carabid beetles of natural forest, managed regenerating natural forest, pine plantation forest and pasture. Methods: We compared the carabid beetle assemblages of natural forest of Nothofagus solandri var solandri (also known as Fuscospora solandri or black beech), regenerating N. solandri forest managed for timber production, exotic pine plantation forest and exotic pasture, using pitfall traps. The study was conducted at Woodside Forest in the foothills of the Southern Alps, North Canterbury, New Zealand, close to an area where the critically endangered carabid Holcaspis brevicula was found. Results: A total of 1192 carabid individuals from 23 species were caught during the study. All but two species were native to New Zealand, with the exotic species present only in low numbers and one of these only in the pasture habitat. Carabid relative abundance and the number of species was highest in the pine plantation, where a total of 15 species were caught; however, rarefied species richness did not differ significantly between habitats. The sampled carabid beetle assemblages were similar across the three forested habitat types but differed significantly from the pasture assemblages based on unconstrained and canonical analyses of principal coordinates. Holcaspis brevicula was not detected in this area. Conclusions: Our results show that managed or exotic habitats may provide habitat to species-rich carabid assemblages although some native species occur only in natural, undisturbed vegetation. Nevertheless, it is important to acknowledge the potential contribution of these land uses and land cover types to the conservation of native biodiversity and to consider how these can be managed to maximise conservation opportunities.


2018 ◽  
Vol 150 (6) ◽  
pp. 813-820
Author(s):  
H.E. James Hammond ◽  
David W. Langor ◽  
Dustin J. Hartley

AbstractThe depth at which pitfall traps were sunk into the ground and the resulting catches of epigaeic Carabidae (Coleoptera) and Staphylinidae (Coleoptera) assemblages in subhygric to hydric ecosites with very deep organic soil layers was investigated in the upper foothills ecoregion of Alberta, Canada. Traps were installed at seven sites, with six surface traps (the pitfall trap lip <5 cm below soil surface) and six deep traps (the pitfall trap lip >20 cm below soil surface) at each site. A total of 5289 beetles representing 75 taxa were collected. There were no significant effects of trap depth on catch. Rarefaction estimates of species diversity were higher in surface pitfall traps for both taxa. The similarity of pooled catches between deep and surface traps was on average 75%, suggesting that both trap types were collecting similar faunas. We found no advantage to using deep pitfall traps in addition to surface traps to sample the epigaeic fauna of wet forest stands and peatlands.


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