Adjusted temperature by precipitation intervals included zero in four insect-catch samples from Sweden and Madagascar in 2019-2020

We tested whether the link between collection-window precipitation and measured flying-insect biomass changed with temperature. We used 5,805 measured catches from 191 Swedish traps and 50 Madagascar traps in 2019-2020, split into two periods per country. Models controlled trap, calendar time, latitude-specific season and collection duration. All four temperature by precipitation estimates were positive. All four confidence intervals included zero after correction for four comparisons. The early Swedish 95 percent interval excluded zero before this correction, but this result did not repeat in the other samples. Tests of collection duration, date alignment, outcome scale and model form did not establish a common interaction. Catches mix insect abundance and flight activity. One year per country, coarse weather, selected samples and few time clusters limit inference. This test does not show that the interaction is absent. It tests no air pollution effect. The package gives source hashes, sample records, code, numerical checks and a figure.

insect biomass · precipitation · temperature · observation bias · seasonality · Malaise traps · null result