Despite many studies of the aging process, questions about key factors ensuring longevity have not yet found clear answers. Temperature seems to be one of the most important factors regulating lifespan. However, the genetic background may also play a key role in determining longevity. The aim of this study was to investigate the relationship between the temperature, genetic background (fruit fly origin), and metabolic rate on lifespan. Experiments were performed with the use of the wild type Drosophila melanogaster fruit flies originating from Australia, Canada, and Benin and the reference OregonR strain. The metabolic rate of D. melanogaster was measured at 20 °C, 25 °C, and 28 °C in an isothermal calorimeter. We found a strong negative relationship between the total heat flow and longevity. A high metabolic rate leads to increased aging in males and females in all strains. Furthermore, our results showed that temperature has a significant effect on fecundity and body weight. We also showed the usefulness of the isothermal calorimetry method to study the effect of environmental stress conditions on the metabolic activity of insects. This may be particularly important for the forecasting of impact of global warming on metabolic activity and lifespan of various insects.

Climate change, and in particular the increase in temperature we are currently observing, can affect herbivorous insects. Aphids, as poikilothermic organisms, are directly exposed to temperature increases that influence their metabolism. Heat stress causes disturbances between the generations and the neutralization of reactive oxygen species (ROS). The aim of this work is focused on explaining how the aphid, using the example of Aphis pomi, responds to abiotic stress caused by temperature increase. The experiment was carried out under controlled conditions at three temperatures: 20, 25, and 28 °C. In the first stage, changes in the activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO), and peroxidase (POD)) were determined in aphid tissues, at each temperature. In the second stage, microcalorimetry monitored changes in heat emitted by aphids, at each temperature. Our results showed that A. pomi defense responses varied depending on temperature and were highest at 28 °C. The flexible activity of enzymes and increase in the metabolic rate played the role of adaptive mechanisms and ran more effectively at higher temperatures. The A. pomi thus protected itself against ROS excessive induction and the aphids were able to respond quickly to environmental stress.

Temperature, being the main factor that has an influence on insects, causes changes in their development, reproduction, winter survival, life cycles, migration timing, and population dynamics. The effects of stress caused by a temperature increase on insects may depend on many factors, such as the frequency, amplitude, duration of the stress, sex, or the developmental stage of the insect. The aim of the study was to determine the differences in the enzymatic activity of nymphs and adult aphids Aphis pomi, Macrosiphum rosae and Cinara cupressi, and changes in their response to a temperature increase from 20 to 28 °C. The activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO) and peroxidase (POD)) in aphid tissues was analysed for three constant temperatures. The results of our research showed that the enzymatic activity of aphids (measured as the activity of antioxidant, detoxifying and oxidoreductive enzymes) was mainly determined by the type of morph. We observed a strong positive correlation between the activity of the detoxifying and oxidoreductive enzymes and aphids’ development, and a negative correlation between the activity of the antioxidant enzymes and aphids’ development. Moreover, the study showed that an increase in temperature caused changes in enzyme activity (especially SOD, CAT and β-glucosidase), which was highest at 28 °C, in both nymphs and adults. Additionally, a strong positive correlation between metabolic activity (heat flow measured by microcalorimeter) and longevity was observed, which confirmed the relationship between these characteristics of aphids. The antioxidant enzyme system is more efficient in aphid nymphs, and during aphid development the activity of antioxidant enzymes decreases. The antioxidant enzyme system in aphids appears to deliver effective protection for nymphs and adults under stressful conditions, such as high temperatures.

Thermal stress in living organisms causes an imbalance between the processes of creating and neutralizing reactive oxygen species (ROS). The work aims to explain changes in the aphid–host plant interaction due to an increase in temperature. Tests were carried out at three constant temperatures (20, 25, or 28 °C). Firstly, changes in development of Macrosiphum rosae were determined. Secondly, the activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO), and peroxidase (POD)) in aphid M. rosae tissues and host plant were analyzed at all temperatures. An increase in temperature to 28 °C had a negative effect on the biology of M. rosae by shortening the period of reproduction and longevity, thus reducing the demographic parameters and fecundity. Two stages of the aphid’s defensive response to short-term (24–96 h) and long-term (2 weeks) thermal stress were observed. Aphid defense responses varied considerably with temperature and were highest at 28 °C. In turn, for the plants, which were exposed to both abiotic stress caused by elevated temperature and biotic stress caused by aphid feeding, their enzymatic defense was more effective at 20 °C, when enzyme activities at their highest were observed.

Robinia pseudoacacia L. is an interesting example of how one plant species can be considered invasive or useful depending on its environment. In the past this tree species was planted for decorative purposes and for wood in Poland. For many years it was recommended in poor and degraded habitats because it facilitated late-successional plant species. The aim of this study was to verify if black locust can still be regarded as a resistant tree species in urban greenery. The health condition of old tree specimens growing along streets and in parks was compared. The occurrence of pests and pathogens on R. pseudoacacia trees was assessed and the content of mineral elements in leaves was examined. The research results showed that the health of black locust trees growing in the urban environment in Polish cities, especially along streets (in comparison to park sites), deteriorated significantly due to the interaction of harmful biotic and abiotic factors. Increased level of toxic metals (Fe, Zn, Pb, Mn and Cd) in plant tissues and the accumulation of pests and pathogens negatively influenced the health of R. pseudoacacia.

One of the consequences of climate change is the expansion of insects’ ranges. Colonization of new habitats forces insects to adapt to new conditions, such as low temperatures in winter. Cinara tujafilina is a thermophilic anholocyclic aphid species, which reproduce exclusively parthenogenetic throughout the year, including winter. On the areas where the populations of C. tujafilina had expanded, it demonstrated its adaptation for surviving colder winters. Based on analyses of changes in body chemical composition using Fourier transform infrared (FTIR) and changes in cryoprotectant content using high performance liquid chromatography (HPLC), we showed how aphid C. tujafilina adapted to overwintering as an active stage. In the FTIR spectrum of the winter type of C. tujafilina, higher peak values originating from the carbohydrates, proteins and lipids, were observed. Glucose, trehalose, mannitol, myo-inositol and glycerol were identified in the aphid body in winter as main putative cryoprotectants to increase the insects’ tolerance to cold. The complex sugar-polyol cryoprotectant system facilitates aphids’ survival in unfavorable low temperatures.