Insects from light trap (1992–2009), rooftop Zoological Museum, Copenhagen

Study Extent

The light trap was installed 17.5 m above ground at the roof of the Zoological Museum in Copenhagen, Denmark (N 55.702512°, E 12.558956°). The trap was placed on an east-facing roof at the museum building in an altitude of 17.5 meter above ground level, viz. above most surrounding buildings and trees. The museum is situated c. 3 km from the centre of Copenhagen.

Sampling

Collecting of night flying insects was carried out with an automatically working modified Robinson light trap. A 250 W mercury vapour bulb was used as light source, and as a killing agent 1,1,2,2-tetrachlorethane was used. The trap worked around 4,500 nights from April to November during the years 1992 to 2009, and was emptied on an approximately weekly basis.

Quality Control

All Lepidoptera and Coleoptera were identified to species, counted and written into a data file, published here. The final data set was subjected to a thorough quality check, and the few records (<20 individual records) in Lepidoptera that could not be accounted for by comparison of collection periods were discarded. We excluded the first (1992) and the last year (2009) of the data set to minimize start-up effects (operating the trap in a standardized manner comparable to the remainder of the study period) and influence from alteration of the local habitat in 2009. Furthermore, in 1992 and 2009 the trap was not active in the entire season. To account for variation in sampling intervals, we grouped the data set into standardized 10-day periods the first starting on 1st of January (Julian Day 1) and the last period ending on December 26 (Julian Day 360). The 10-day interval is slightly longer than the mean sampling interval of 7 days. Furthermore, all handling and identification of material was carried out consistently throughout the entire period by the same group of researchers.

Method steps

1. In the study, all individual records of Lepidoptera and Coleoptera were collected, identified to species level and counted yielding qualitative (species) and quantitative (number of individuals within each species) data for the entire study period.
2. All handling and identification of material was carried out consistently throughout the entire period by the same group of researchers.
3. A portion of the material was pinned and is preserved in the Zoological Museum, University of Copenhagen. Note specimen records are not included in this dataset.
4. A custom Java program was used to clean, augment, and parse the raw data into source data files that were uploaded and mapped in the IPT. For the purpose of inspiration for normalising other datasets, the Java program can be found here: https://github.com/kbraak/refine/blob/master/src/main/java/org/gbif/refine/datasets/nhmd/RooftopBugs.java

1076 species of Lepidoptera, representing 52 families. 467 species of Coleoptera, representing 52 families.

1. Lepidoptera
   rank: order
2. Coleoptera
   rank: order

Rooftop of Natural History Museum Denmark, Copenhagen, Denmark