Wettest-day rain gave no clear common insect-catch link in four Sweden and Madagascar samples in 2019-2020

We tested whether the largest daily precipitation total in a collection window had a link to flying-insect catch biomass after controls for mean rain, wet-day fraction and temperature. Four trap and season models used 5,805 measured catches from Sweden in 2019 and Madagascar in 2019-2020. Slopes ranged from -0.008 to 0.008 log(1 + grams/day) per 10 mm of wettest-day precipitation. All four confidence intervals included zero after correction for four tests. This does not show that rain concentration has no effect. Catches mix insect abundance and flight activity. One sampling year per country, selected samples, gridded weather, correlated rain features and few time clusters limit inference. We test no air pollution or climate trend. The package gives aggregate results, code, source hashes, a figure and a retrieval recipe. Record-level data remain outside the bundle.

insect biomass · rainfall concentration · observation bias · Malaise traps · Sweden · Madagascar · null result