Temperature Tolerance and Thermal Environment of European Seed Bugs

Abstract

Heteroptera, or true bugs populate many climate zones, coping with different environmental conditions. The aim of this study was the evaluation of their thermal limits and derived traits, as well as climatological parameters which might influence their distribution. We assessed the thermal limits (critical thermal maxima, CTmax, and minima, CTmin) of eight seed bug species (Lygaeidae, Pyrrhocoridae) distributed over four Köppen–Geiger climate classification types (KCC), approximately 6° of latitude, and four European countries (Austria, Italy, Croatia, Bulgaria). In test tubes, a temperature ramp was driven down to −5 °C for CTmin and up to 50 °C for CTmax (0.25 °C/min) until the bugs’ voluntary, coordinated movement stopped. In contrast to CTmin, CTmax depended significantly on KCC, species, and body mass. CTmax showed high correlation with bioclimatic parameters such as annual mean temperature and mean maximum temperature of warmest month (BIO5), as well as three parameters representing temperature variability. CTmin correlated with mean annual temperature, mean minimum temperature of coldest month (BIO6), and two parameters representing variability. Although the derived trait cold tolerance (TC = BIO6 − CTmin) depended on several bioclimatic variables, heat tolerance (TH = CTmax − BIO5) showed no correlation. Seed bugs seem to have potential for further range shifts in the face of global warming.

Selection of the Gridded Temperature Dataset for Assessment of Thermal Bioclimatic Environment Changes in Amu Darya River Basin

“…TBI3 showed a higher increase in temperature in cold months than in warmer months, which is significant in the cold region of the basin. This indicates the significant influence of TBI3 on critical thermal tolerance (Käfer et al, 2020). The trends in TBI4 collaborates with the results obtained by (Hadi Pour et al, 2019) in Iran.…”

“…Sosa and Loera (2017) found the highest positive correlation of TBI1 with species richness in Mesoamerica among all other indicators. Käfer et al (2020) assessed the thermal limits of European Seed Bugs, critical to thermal maxima (mean=45.3℃) and showed their high correlation with TBI1 and TBI5. The decrease in TBI1 over a major region of ADRB can have severe negative implications on vegetation and ecology in the basin.…”

The Respiratory Metabolism of Polistes biglumis, a Paper Wasp from Mountainous Regions

“…In contrast to the SMR, the upper thermal limit or CT max of activity we determined for Polistes biglumis (CT max = 47.2 • C) was virtually identical to that of Polistes dominula (CT max = 47.1 • C) [18]. This is a surprising result, as one would expect that the species living in a warmer habitat has been endowed with a higher thermal tolerance (upper thermal limit), as was determined in seed bug species [39]. Therefore, we suggest that the lower metabolism and thermal sensitivity in P. biglumis is not a result of a simple shift of the range of thermal tolerance (CT max − CT min ) to higher temperatures, as would be expected by a shift of the whole metabolic curve to higher temperatures (as might be expected by generally higher thermal optima of the involved enzymes).…”

Overwintering Larval Cold Tolerance of Sirex noctilio (Hymenoptera: Siricidae): Geographic Variation in Northeast China

“…Nonetheless, the temperature was not the only factor limiting the larval cold tolerance [ 14 ]. According to the climate variability hypothesis, geographical latitude, seasonality in temperature and also elevation above sea level are thought to correlate with the animals’ temperature tolerance breadth [ 27 , 28 ] (see for instance [ 29 , 30 , 31 ]). In our study, the average SCPs of different populations were ranked in the same patens with the latitude of our collection sites.…”