Environmental Influence on Flight Activity and Arrival Patterns of Aerial Colonizers of Temporary Ponds

Abstract

Arrival of aerial insect colonizers was studied (from April to July) using traps (artificial pools) installed adjacent to two temporary ponds in southern Ontario, Canada. The two ponds differed in the length of their hydroperiod: Pond I held water for 98 days, whereas Pond II held water for 34 days. The duration of the study was 15 weeks, during which two phases (wet and dry) were distinguished in each trap according to the presence or absence of water in their respective ponds. Atmospheric, habitat and pond variables were measured to determine the variations in the composition and in the richness and abundance of the aerial colonizers. Taxa captured arriving at the two traps by flight comprised 11 and 57 species of Hemiptera and Coleoptera, respectively. Multivariate analysis (CCA) and mixed linear effects models (LME and GLMM) showed that arrival phenology was more related to habitat condition (pond or phase) than to atmospheric conditions, although wind speed and minimum relative humidity appeared to play a secondary role. Arrival patterns were classifiable into four types (using GAM models), with all four observed in both ponds. While some species exhibited similar arrival patterns in both ponds, others did not.

Seasonality and weather conditions jointly drive flight activity patterns of aquatic and terrestrial chironomids

“…On the seasonal timescale, total flight activity of both groups also declined with increasing wind speeds. This is consistent with reported strong declines in flight activity with rising wind speeds or a complete cessation of flight above a certain wind threshold in stoneflies [ 12 ], water beetles and bugs [ 13 , 14 , 18 , 57 ], biting midges [ 22 ], black flies [ 21 ], and swarming chironomids [ 58 ]. In our data, the decline was steeper and wind speed explained a substantial proportion of variability in species composition in terrestrial species.…”

“…Their total flight activity declined with relative humidity on both diel and seasonal timescales. Although similar result were found for aquatic beetles and heteropteran bugs [ 18 ], previous studies on dipterans found purely or predominantly positive relationships between relative humidity and flight activity [ 17 , 21 , 22 ]. Aquatic taxa in our study also flew less at higher temperatures at the diel timescale, which contrasted with an increasing trend in flight activity at higher temperatures across the season.…”

“…Humidity but not temperature affected the species composition of terrestrial community and neither had an effect on the aquatic community. Previous studies reported that aquatic insects fly more at higher air temperatures (Trichoptera: [ 11 ]; Heteroptera: [ 56 ]; Plecoptera: [ 12 ]; Chironomidae: [ 24 ]) or lower humidity (Coleoptera and Heteroptera: [ 18 ]), although the responses were sometimes sex ( Culicoides : [ 22 ]) or species specific ( Culicoides : [ 23 ]) or varied in time ( Simulium : [ 21 ]). Seasonality of air temperature is also responsible for seasonal changes in diel activity patterns in Coleoptera and Heteroptera [ 6 ].…”

“…Seasonality of air temperature is also responsible for seasonal changes in diel activity patterns in Coleoptera and Heteroptera [ 6 ]. However, earlier analyses ignored the collinearity of weather characteristics (but see [ 12 , 18 ]) and their seasonal variation (but see [ 12 , 23 ]).…”

“…Flight activity of aquatic insects is strongly affected by weather conditions including air temperature [ 6 , 11 , 12 ], wind speed [ 12 – 14 ], light intensity [ 15 , 16 ], and relative air humidity (i.e., the amount of water vapour in the air relative to the full saturation) [ 17 , 18 ]. Weather conditions thus represent a strong environmental filter [ 19 , 20 ] that ultimately affects individual fitness.…”