Possibility of studying earthworm feeding ecology using mid-range infrared spectrometry

This study explored the use of mid-infrared (IR) spectrometry as a technique for identifying earthworm dietary preferences. In controlled laboratory-based experiment, we examined how consumption of three different types of leaf litter – Populus tremula, P. sibirica, and Acer negundo – affects the IR spectra of three earthworm species – Eisenia nana, E. nordenskioldi, and E. ventripapillata. To conduct the analysis, tablets of a mixture with potassium bromide in a ratio of 1:200 were prepared from the sample. The spectrum of pure potassium bromide was used as a reference. The measurements were performed on an FT-801 IR Fourier spectrometer (SIMEX) in the range of 500–4000 cm–1 (number of scans: 32, resolution: 4 cm–1). The spectra were processed using ZaIR3.5 software (SIMEKS). The position, intensity, and area of absorption bands (AB) were determined on all spectra.