LAUSR

Abstract This article investigates inter-individual repeatability in distance moved in an open-field test for larval Limnephilus lunatus Curtis, 1834. Repeatability across four trials (two-day trial intervals) was comparable to previous studies on arthropod species (repeatability: R = 0.37), indicating that L. lunatus is a suitable model species in this research field. Two potential nuisance factors were corrected for: (1) progressively declining activity over consecutive trials and (2) case mass:body mass ratio, affecting activity negatively. These factors require consideration in behavioural experiments on larval caddisflies. Pairwise correlations of distance moved among trial days showed that behaviour in the first trial did not correspond well with behaviour in the following trials. Re-analysing the data using only trials 2 to 4 increased the repeatability (repeatability: R = 0.50), suggesting that future studies should consider not including data derived from initial trials, as the initial trial may constitute a different context than the following ones.