Body size, metabolic rate and diapause in the oriental hornet (Vespa orientalis), in two extreme climatic regions

Abstract

Temperature and precipitation are major components of climate that have a pervasive effect on the phenotype and physiology of insects. The Oriental hornet has a wide geographical distribution and is the only vespid species found in a desert environment. Recently, it has extended its geographic distribution due to climate change and human activities. We compared the standard metabolic rate, diapause metabolic rate and body size of workers and gynes in two different climatic regions, 150 km apart along the northern part of the Great Rift Valley in Israel: In the north, high elevation Mediterranean habitat and in the south, low elevation, warm and dry desert. The brood in the desert region developed in higher ambient temperatures than in the Mediterranean, but only the workers of the desert had a smaller body size as adults. Worker hornets from the Mediterranean region had a higher standard metabolic rate (SMR) at the environmental temperature of main activity compared to desert hornets. Queens had a typical discontinuous gas exchange cycles (DGC) pattern, with Mediterranean queens having a 30% lower SMR. Such lower SMR might reflect an adaptation for prolonged and more profound diapause typical to the cold and long winter conditions in this region.

Invasion potential of hornets (Hymenoptera: Vespidae: Vespa spp.)

“…While in pre-nesting diapause, mated gynes are inactive and subsist on internal reserves of lipids acquired before departing their natal nest and stored in their fat body ( 2 , 76 ). The amount of fat a gyne has stored affects her survival during diapause and may influence nest founding ( 3 , 77 ).…”

Ecophysiological trait variation in desert versus Mediterranean populations of a gecko

“…An empty cell was used as a baseline reference and was measured for 10 min every 40 min (every two cycles). Atmospheric air was dried of water and absorbed from CO 2 by passing through a column of magnesium perchlorate (water absorbent) and Ascarite® (CO 2 absorbent), and it then flowed at a rate of 50 mL × min −1 (Clemente et al., 2009; Cohen et al., 2022; V8, eight‐channel flow mass control, Sable Systems, Las Vegas, Nevada) into each metabolic chamber. Air exiting the chambers passed through a Li‐7000 CO 2 /H 2 O analyzer (Licor, Lincoln, Nebraska, USA) and then through a column of magnesium perchlorate and Ascarite® (water and CO 2 adsorbents, respectively) into an O 2 analyzer (Oxzilla II, Sable Systems, Las Vegas, Nevada).…”

Interactive effects of intrinsic and extrinsic factors on metabolic rate

“…[24,[38][39][40][41][42]44,93,94]) life-history stage (e.g. [20,32,40,[47][48][49][50]66,91,123,126,[129][130][131][132][133][134][135][136][137][138][139][140][141][142][143][144][145][146][147]) interactive effects of intrinsic factors ecological life style pelagic versus benthic (e.g. [20,24,34,40,92,93]) food habits (e.g.…”

“…Higher temperature speeds up metabolism, whereas higher salinity reduces osmoregulatory metabolic demand in marine organisms. However, hypersaline conditions may increase metabolic costs in freshwater/estuarine organisms [120][121][122][123] temperature and pH (CO 2 ) variable (species-specific) combined effects of temperature and acidification (CO 2 levels) vary with species for unknown reasons [124,125] ( [84,121,126,127] temperature and food supply complex thermal sensitivity of metabolism varies with food supply in complex ways [128,129] temperature and toxicants complex thermal sensitivity of metabolic rate in a moth depended on an insecticide treatment when acclimated at 22°C, but not when acclimated at 28°C [130] temperature and microplastics complex in an aquatic amphipod, temperature effects are positive at low microplastic concentration, but negative at high microplastic concentration, for unknown reasons [131] temperature and latitude positive (low to high latitude) high-latitude populations in relatively cool habitats tend to show more thermal sensitivity of metabolic rate than that of low latitude populations in warmer habitats [132][133][134][135] temperature and altitude positive (low to high altitude) a high-altitude population of the tsetse fly Glossina pallidipes in a cool habitat showed higher temperature sensitivity of metabolic rate than did lowaltitude populations in warmer habitats [136] temperature and ecological life style complex invasive crayfish show higher metabolic rates at warm temperatures, but lower metabolic rates at cooler temperatures than do native crayfish [137] light and predator cues positive or negative metabolic rate of an aquatic amphipod changes in response to fish predator cues in light, but not in dark [138] interactive effects of intrinsic and extrinsic factors type direction of interactive effect a underlying mechanism selected sources body size and ecological life style pelagic versus benthic positive or negative (comparing pelagic species to benthic species) pelagic invertebrate/protist species (or life-stages) tend to show steeper metabolic scaling than do related benthic species (or life-stages), possibly because of age-and size-specific differences in locomotor costs, cellular mode of growth, or predation-caused rates of mortality, growth and reproduction. Opposite patterns are shown for teleost fishes, possibly owing, at least in part, to their lesser vulnerability to predation (associated with their larger body size and more rapid escape movements), and to thei...…”