The use of low cost compact cameras with focus stacking functionality in entomological digitization projects

Digitization of specimen collections has become a key priority of many natural history museums. The camera systems built for this purpose are expensive, providing a barrier in institutes with limited funding, and therefore hampering progress. An assessment is made on whether a low cost compact camera with image stacking functionality can help expedite the digitization process in large museums or provide smaller institutes and amateur entomologists with the means to digitize their collections. Images of a professional setup were compared with the Olympus Stylus TG-4 Tough, a low-cost compact camera with internal focus stacking functions. Parameters considered include image quality, digitization speed, price, and ease-of-use. The compact camera’s image quality, although inferior to the professional setup, is exceptional considering its fourfold lower price point. Producing the image slices in the compact camera is a matter of seconds and when optimal image quality is less of a priority, the internal stacking function omits the need for dedicated stacking software altogether, further decreasing the cost and speeding up the process. In general, it is found that, aware of its limitations, this compact camera is capable of digitizing entomological collections with sufficient quality. As technology advances, more institutes and amateur entomologists will be able to easily and affordably catalogue their specimens

Inter- and intrafield distribution of cereal leaf beetle species (coleoptera : chrysomelidae) in Belgian winter wheat

Cereal leaf beetles (CLBs), a group of chrysomelid beetles of the genus Oulema (Coleoptera: Chrysomelidae), are well-known pest insects of small-grain cereals in many countries of the Northern hemisphere. Due to the small differences in morphology of species within this genus, classification up to species level remains a challenging task. Since an accurate view of species composition is important for developing targeted control strategies, the goal of this study was to unravel the Oulema species composition in Flanders' wheat fields. During three subsequent years at a series of different fields, Oulema species were collected and classified up to species level (2016: 28 fields, 2017: 30 fields, and 2018: 23 fields). This study reveals that the population consists of four different species: Oulema melanopus, Oulema duftschmidi, and Oulema obscura were most frequently encountered, while Oulema rufocyanea was only marginally present. Furthermore, the population was highly dynamic, as the population share of each species varied between different growing seasons and between the various sampling events within each season. The distance from the field edge had a minor influence on the species composition, but the abundance of beetles increased with the distance to the field edge. A discriminant analysis revealed that based on the measurements of various body parts, an accurate classification up to species level is possible. In conclusion, we observed that the population densities fluctuated within and between years, resulting in variable incidence of CLB in winter wheat fields in the Flanders region

From theory to practice: a photographic inventory of museum collections to optimize collection management

The digitization of museum specimens is a key priority in the Digital Era. Digital databases help to avoid unnecessary manipulation hazards to delicate collections, increase their accessibility to third party researchers, and contribute to the ongoing documentation of global biodiversity. Time, workforce and the need of specialized infrastructures limit the processing of the vast number of specimens in natural history collections. Cheaper, easy-to-use methods and volunteer programs are developing quickly to help bridge the gap. We present the results of combining citizen science for the digitization of an entomological collection in conjunction with the cooperation of a taxonomic expert for the remote identification of samples. In addition, we provide an assessment of the avoided monetary costs and the time needed for each step of the process. A photographic inventory of specimens belonging to the leaf beetle genus Calligrapha was compiled by volunteers using a low-cost compact camera and the species were identified using these images. Using digital photographs allowed for a rapid screening of specimens in the collection and resulted in an updated taxonomic identification of the Calligrapha collection at the Royal Belgian Institute of Natural Sciences. The pictures of the specimens and their original labels, as well as the new information from this endeavor were placed in an online public catalogue. This study demonstrates a worked example of how digitization has led to a practical, useful outcome through cooperation with an end user and highlights the value of museum collection digitization projects

Degradation legacy and current water levels as predictors of carbon emissions from two fen sites

Drainage-induced shifts in physicochemical peat properties are irreversible on a decadal time span. We investigated whether carbon emissions from fen peat can be estimated using two proxies: current water levels and peat properties (as affected by drainage history, i.e. degradation legacy). We collected bare peat monoliths from a long-term drained and an undrained fen. In a crossed design, half of the monoliths was kept wet and the other half was drained. Highest carbon dioxide (CO2) emissions came from the originally undrained peat under low water levels (607 mmol m-2 d-1). Overall, CO2 emissions were primarily determined by drainage history, with 141 % higher emissions from the originally undrained peat. In addition, low current water levels correlated with 42 % higher emissions. Highest methane (CH4) emissions were measured in the originally undrained peat under high water levels (123 mmol m-2 d-1). Overall, CH4 emissions were primarily determined by current water levels, with 430 % higher emissions under high water levels. In addition, the originally undrained peat had 180 % higher emissions. The lower C efflux from originally drained peat correlated with lower concentrations of methanogens and of easily-degradable carbon substrate (cellulose). We conclude that substrate limitation in long-term drained fens ensures low baseline carbon emissions, which provides opportunities for renewed carbon sequestration by rewetting

From \u2018Open Science\u2019 to \u2018Science\u2019, lessons learned from this year\u2019s Open Access week.

Abstract: During the yearly institutional Open Access Week of 2020, several presentations were given by University of Antwerp staff. Additionally, some blog posts were launched to state viewpoints on Open Access by staff and researchers. The present blog post summarizes the presentations given, and sheds some light on the overarching conclusions reached during the thematic week

Longhorned woodboring beetles (Coleoptera, Cerambycidae) from Cusuco National Park, Honduras: new species, new records, and revalidation

An ongoing study of the longhorned beetle fauna in the cloud forests of Cusuco National Park revealed multiple additions to the Honduran fauna. Four new species are described: Heterachthes caceresae sp. nov. (Cerambycinae, Neoibidionini), Oreodera kawasae sp. nov. (Lamiinae, Acrocinini), Phrynidius guifarroi sp. nov. (Lamiinae, Apomecynini), and Strangalia lunai sp. nov. (Lepturinae, Lepturini). Additionally, Lagocheirus parvulus Casey, 1913 (Lamiinae, Acanthocinini) is revalidated as Lagocheirus araneiformis parvulus Casey, 1913 (Lagochirus [sic]). We recorded Arixiuna varians (Bates, 1881) (Lamiinae, Hemilophini) for the first time for Honduras. These findings confirm how poorly the invertebrate biodiversity of cloud forests is documented and hints at the large number of species we are losing with the ongoing deforestation

Supplementary material 2 from: Mertens JEJ, Van Roie M, Merckx J, Dekoninck W (2017) The use of low cost compact cameras with focus stacking functionality in entomological digitization projects. ZooKeys 712: 141-154. https://doi.org/10.3897/zookeys.712.20505

Figure S2 : Explanation note: Comparison of the narrow (C, F), normal (A, B, D, G) and wide (E, H) focal step size in two specimens of different 'depth' (A, C–E: Allochroma sp., 2 mm deep; B, E–H: Doryphora sp., 12 mm deep, measured from top of elytra to lowest tarsi). The narrow setting is marginally sharper in some areas; however, deeper parts of the specimen are not in focus. The wide setting produces artefacts around some of the edges, sometimes resulting in less sharp regions