At 47 NEON sites in 2014–2024, the effect of a warm 14-day anomaly on mosquito trap catch changed sign at 15–19 °C under two sample filters and two weightings, below lab optima of 23–25 °C

This version supersedes SCI 2ad8cbcf. It adds citations of two concurrent studies, a reconciliation with one of them, a trap-night control and a corrected H1 statement. Question: lab thermal performance curves predict that mosquito density is unimodal in temperature, with transmission optima of 23.9–25.2 °C for the North American Culex vectors of West Nile virus. Then a warm anomaly must increase catch below the optimum and decrease it above. Approach: we used night CO2-trap samples at 513 trap locations on 47 NEON sites (2014–2024, RELEASE-2026 via neonDivData) and Daymet air temperature at each trap. A Poisson model with fixed effects for trap location, site-year and site by calendar week gave the effect of the 14-day anomaly before collection as a linear function of the 1995–2024 climatological temperature. Result: in the primary sample (43,110 samples) the effect decreased by 0.023 log units per °C of climatology (SE 0.0075). It was +0.18 per °C (SE 0.054) at a 10 °C climatology and −0.17 (SE 0.064) at 25 °C, and it crossed zero at 17.7 °C (site bootstrap 16.4–20.5 °C). The crossing stayed at 16.0–20.6 °C for other windows, a trap-night temperature control, equal site weights and leave-one-site-out fits, and a placebo with the anomaly after collection gave no interaction. Reconciliation: SCI 7051337e found no cool-side increase with the same counts. The difference is about 4,000 samples, mostly very large catches, that NEON flags as damaged at identification. With these samples kept, the crossing was 15.1 °C (7.4–19.3) with count weights, where the cool-side increase was not significant, and 17.8 °C with equal site weights, where it was significant (+0.13, SE 0.04). In all four filter and weighting combinations the crossing was below the lab transmission optima, and at most 0.5% of bootstrap draws reached 22.7 °C. Lab density curves that we fitted to Culex trait data peak at 19.5–23.2 °C. Limitations: the decrease was clearer in the rising half of the season, a phenology-shift term explained part of it, catch shows activity as well as abundance, Daymet is air temperature, and Culex pipiens and quinquefasciatus were rare.

mosquito · thermal performance curve · NEON · temperature anomaly · thermal optimum · Culicidae · CO2 trap · Daymet · West Nile virus vectors · phenology · Poisson fixed effects · field test of lab predictions