In 26 of 29 mosquito species at 47 NEON sites (2014–2024), the trap-catch effect of a warm 28-day period decreased as usual temperature increased, as in total catch

Question: laboratory thermal curves predict that warming increases mosquito density below a thermal optimum and decreases it above. SCI studies of total NEON trap catch found that the effect of a warm 14-day anomaly changes sign near 15–19 °C. A total catch mixes species, so this pattern can come from species turnover only. We tested it inside species. Approach: 47,301 night CO2-trap samples (NEON DP1.10043.001 RELEASE-2026 via neonDivData; 47 sites; 2014–2024) and Daymet temperature at 518 trap points. For each of 29 species (8–29 sites each), a Poisson model with a seasonal curve for each site gave the effect of the 28-day temperature anomaly as a function of the 1994–2024 usual temperature for that trap and date. Results: the anomaly effect decreased as usual temperature increased in 26 of 29 species (13 significant, none significantly positive). The mean slope was −0.038 log units per °C of anomaly per °C of usual temperature (joint site bootstrap 95% interval −0.060 to −0.015). This is equal to the total-catch slope (−0.037, SE 0.005; zero crossing 17.2 °C). The result held in nine model variants (20–27 of 29 species negative) and before and after the seasonal peak. At equal usual temperature, the effect did not change detectably with the thermal niche of the species (all bootstrap intervals included zero). For Culex tarsalis, a lab abundance curve fitted again to Shocket et al. (2020) trait data peaks at 22.8 °C. Above 24 °C the field effect (−0.44 per °C, 95% −0.70 to −0.22) agreed with the lab prediction (−0.25). At 16 °C or less, the lab curve predicts +0.43 but the field effect was −0.55 (−1.31 to +0.04); the difference was −0.98 (−1.74 to −0.34). Limitations: trap catch shows activity as well as abundance; usual temperature is linked to season and region; the class means across species were not well resolved; the tests were designed after the total-catch results were known; the analysis shows association, not cause.

mosquitoes · thermal performance curve · NEON · temperature anomaly · Culex tarsalis · within-species response · climate warming · vector ecology · Daymet · Poisson regression