Differential thermal tolerance across life stages under extreme high temperatures crossed with feeding status in corn leaf aphid

2020 ◽  
Author(s):  
Yu Chen ◽  
Yudong Quan ◽  
François Verheggen ◽  
Zhenying Wang ◽  
Frederic Francis ◽  
...  
2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yu Chen ◽  
François J. Verheggen ◽  
Dandan Sun ◽  
Zhenying Wang ◽  
Frederic Francis ◽  
...  

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3112 ◽  
Author(s):  
Thomas Enriquez ◽  
Hervé Colinet

The spotted wing Drosophila,Drosophila suzukii, is a new pest in Europe and America which causes severe damages, mostly to stone fruit crops. Temperature and humidity are among the most important abiotic factors governing insect development and fitness. In many situations, temperature can become stressful thus compromising survival. The ability to cope with thermal stress depends on basal level of thermal tolerance. Basic knowledge on temperature-dependent mortality ofD. suzukiiis essential to facilitate management of this pest. The objective of the present study was to investigateD. suzukiibasal cold and heat tolerance. Adults and pupae were subjected to six low temperatures (−5–7.5 °C) and seven high temperatures (30–37 °C) for various durations, and survival-time-temperature relationships were investigated. Data showed that males were globally more cold tolerant than females. At temperature above 5 °C, adult cold mortality became minor even after prolonged exposures (e.g., only 20% mortality after one month at 7.5 °C). Heat tolerance of males was lower than that of females at the highest tested temperatures (34, 35 and 37 °C). Pupae appeared much less cold tolerant than adults at all temperatures (e.g., Lt50at 5° C: 4–5 d for adultsvs.21 h for pupae). Pupae were more heat tolerant than adults at the most extreme high temperatures (e.g., Lt50at 37 °C: 30 min for adultsvs.4 h for pupae). The pupal thermal tolerance was further investigated under lowvs.high humidity. Low relative humidity did not affect pupal cold survival, but it reduced survival under heat stress. Overall, this study shows that survival ofD. suzukiiunder heat and cold conditions can vary with stress intensity, duration, humidity, sex and stage, and the methodological approach used here, which was based on thermal tolerance landscapes, provides a comprehensive description ofD. suzukiithermal tolerance and limits.


Science ◽  
2020 ◽  
Vol 369 (6499) ◽  
pp. 65-70 ◽  
Author(s):  
Flemming T. Dahlke ◽  
Sylke Wohlrab ◽  
Martin Butzin ◽  
Hans-Otto Pörtner

Species’ vulnerability to climate change depends on the most temperature-sensitive life stages, but for major animal groups such as fish, life cycle bottlenecks are often not clearly defined. We used observational, experimental, and phylogenetic data to assess stage-specific thermal tolerance metrics for 694 marine and freshwater fish species from all climate zones. Our analysis shows that spawning adults and embryos consistently have narrower tolerance ranges than larvae and nonreproductive adults and are most vulnerable to climate warming. The sequence of stage-specific thermal tolerance corresponds with the oxygen-limitation hypothesis, suggesting a mechanistic link between ontogenetic changes in cardiorespiratory (aerobic) capacity and tolerance to temperature extremes. A logarithmic inverse correlation between the temperature dependence of physiological rates (development and oxygen consumption) and thermal tolerance range is proposed to reflect a fundamental, energetic trade-off in thermal adaptation. Scenario-based climate projections considering the most critical life stages (spawners and embryos) clearly identify the temperature requirements for reproduction as a critical bottleneck in the life cycle of fish. By 2100, depending on the Shared Socioeconomic Pathway (SSP) scenario followed, the percentages of species potentially affected by water temperatures exceeding their tolerance limit for reproduction range from ~10% (SSP 1–1.9) to ~60% (SSP 5–8.5). Efforts to meet ambitious climate targets (SSP 1–1.9) could therefore benefit many fish species and people who depend on healthy fish stocks.


2020 ◽  
Author(s):  
Victor H. Gonzalez ◽  
John M. Hranitz ◽  
Mercedes B. McGonigle ◽  
Rachel E. Manweiler ◽  
Deborah R. Smith ◽  
...  

AbstractThe European honey bee, Apis mellifera L., is the single most valuable managed pollinator in the world. Poor colony health or unusually high colony losses of managed honey bees result from myriad stressors, which are more harmful in combination. Climate change is expected to accentuate the effects of these stressors, but the physiological and behavioral responses of honey bees to high temperatures while under simultaneous pressure of one or more stressors remains largely unknown. Here we test the hypothesis that exposure to acute, sublethal doses of neonicotinoid insecticides reduce thermal tolerance in honey bees. We administered to bees oral doses of imidacloprid and acetamiprid at 1/5, 1/20, and 1/100 of LD50 and measured their heat tolerance 4 h post-feeding, using both dynamic and static protocols. Contrary to our expectations, acute exposure to sublethal doses of both pesticides resulted in higher thermal tolerance and greater survival rates of bees. Bees that ingested the higher doses of pesticides displayed a critical thermal maximum from 2 °C to 4 °C greater than that of the control group, and a reduction in mortality from 69% to 96%. Our study suggests a resilience of honey bees to high temperatures when other stressors are present, which is consistent with studies in other insects. We discuss the implications of these results and hypothesize that this compensatory effect is likely due to induction of heat shock proteins by the insecticides, which provides temporary protection from extremely high temperatures.


1970 ◽  
Vol 27 (11) ◽  
pp. 2047-2052 ◽  
Author(s):  
Thomas A. Edsall ◽  
Donald V. Rottiers ◽  
Edward H. Brown

Juvenile and young adult bloaters (Coregonus hoyi) were tested for tolerance to high temperatures. The ultimate upper lethal temperature of juvenile bloaters (26.75 C) appeared to be slightly higher than that of young adult bloaters, but was similar to that of juvenile ciscoes, Coregonus artedii (26.0 C), the only other North American coregonine for which a detailed description of temperature tolerance has been published.Regression equations are given that permit estimation of the thermal tolerance when the lethal temperatures are incompletely known. The estimated thermal tolerance of juvenile bloaters (617 units) was slightly less than that of the brook trout (Salvelinus fontinalis; 625 units), but was higher than that of other Salmonidae.


2020 ◽  
Author(s):  
Anna H. Andreassen ◽  
Petter Hall ◽  
Pouya Khatibzadeh ◽  
Fredrik Jutfelt ◽  
Florence Kermen

ABSTRACTUnderstanding animal thermal tolerance is crucial to predict how animals will respond to increasingly warmer temperatures, and to mitigate the impact of the climate change on species survival. Yet, the physiological mechanisms underlying animal thermal tolerance are largely unknown. In this study, we developed a method for measuring upper thermal limit (CTmax) in larval zebrafish (Danio rerio) and found that it occurs at similar temperatures as in adult zebrafish. We discovered that CTmax precedes a transient, heat-induced brain-wide depolarization during heat ramping. By monitoring heart rate, we established that cardiac function is sub-optimal during the period where CTmax and brain depolarization occur. In addition, we found that oxygen availability affects both locomotor neural activity and CTmax during a heat stress. The findings of this study suggest that neural impairment due to limited oxygen availability at high temperatures can cause CTmax in zebrafish.HighlightsLarval zebrafish reach their critical thermal limit (CTmax) at similar temperature as adult zebrafishAcute heat stress causes a brain-wide spreading depolarization near the upper thermal limitCTmax precedes brain-wide depolarizationHeart rate declines at high temperatures but is maintained during CTmax and brain depolarizationNeural activity is impaired prior to CTmax and brain-wide depolarizationOxygen availability in the water affects both CTmax and neural activity


1954 ◽  
Vol 32 (1) ◽  
pp. 30-38 ◽  
Author(s):  
D. P. Pielou ◽  
R. F. Glasser

The lethal effects of high temperatures were investigated on Macrocentrus ancy-livorus Roh., a parasite of the oriental fruit moth. Day-old adults were exposed to uniform high temperatures for fixed periods ranging from 15 min. to 8 hr. in different tests. Temperatures investigated ranged from 30° to 45 °C. The insects had been reared under uniform and rigidly specified conditions at constant temperatures. After exposure all the test insects were removed, put in bottles, and provided with 10% sucrose solutions as food. Mortality was recorded 24 hr. later. Sexes were kept separate. Tests at all temperatures and exposure times were carried out both in dry and in moist air. At temperatures up to 34 °C. mortality was light even at the 8-hr. exposure. At 44 °C. almost 100% mortality was recorded at the 1/2-hr. exposure. Between these limits mortality increased with higher temperature or lengthened exposure time; it was generally greater in dry air than in moist. Females were more resistant than males. Thermograph records from the peach growing areas of the Niagara peninsula showed that only in exceptionally hot summers could conditions cause appreciable death from the direct action of temperature alone.


2016 ◽  
Author(s):  
Thomas Enriquez ◽  
Hercé Colinet

The spotted wing Drosophila, Drosophila suzukii, is a new pest in Europe and America which causes severe damages to stone fruits crops. Temperature and humidity are among the most important abiotic factors governing insect life. In many situations, temperature can become stressful thus compromising fitness and survival. The ability to cope with thermal stress depends on basal level of thermal tolerance. Basic knowledge on temperature-dependent mortality of D. suzukii is essential to facilitate management of this pest. The objective of the present study was to investigate D. suzukii basal cold and heat tolerance. Adults and pupae were submitted to six low (-5 to 7.5 °C) and seven high temperatures (30 to 37 °C) for various durations, and survival-time-temperature relationships were investigated. In addition, pupal thermal tolerance was analyzed under low vs. high relative humidity. Our results showed that males had higher cold survival than females, and pupae appeared less cold-tolerant than adults. Above 5 °C, adult cold mortality became minor, even after prolonged exposures (i.e. one month). Males were less heat tolerant than females, and pupae showed a better survival to extreme high temperatures than adults. Low relative humidity did not affect D. suzukii cold survival, but reduced survival under heat stress. Overall, this study shows that survival of D. suzukii under heat and cold conditions depends on both stress intensity and duration, and the methodological approach used here, which was based on thermal tolerance landscapes, provides a comprehensive description of D. suzukii thermal tolerance and limits.


Author(s):  
Benjamin Walsh ◽  
Steven Parratt ◽  
Natasha Mannion ◽  
Rhonda Snook ◽  
Amanda Bretman ◽  
...  

The impact of rising global temperatures on survival and reproduction is putting many species at risk of extinction. In particular, it has recently been shown that thermal effects on reproduction, especially limits to male fertility, can underpin species distributions in insects. However, the physiological factors influencing fertility at high temperatures are poorly understood. Key factors that affect somatic thermal tolerance such as hardening, the ability to phenotypically increase thermal tolerance after a mild heat shock, and the differential impact of temperature on different life stages, are largely unexplored for thermal fertility tolerance. Here, we examine the impact of high temperatures on male fertility in the cosmopolitan fruit fly Drosophila virilis. We first determined whether temperature stress at either the pupal or adult life-history stage impacts fertility. We then tested the capacity for heat-hardening to mitigate heat-induced sterility. We found that thermal stress reduces fertility in different ways in pupae and adults. Pupal heat stress delays sexual maturity, whereas males heated as adults can reproduce initially following heat stress, but lose the ability to produce offspring. We also found evidence that while heat-hardening in D. virilis can improve high temperature survival, there is no significant protective impact of this same hardening treatment on fertility. These results suggest that males may be unable to prevent the costs of high temperature stress on fertility through heat-hardening which limits a species’ ability to quickly and effectively reduce fertility loss in the face of short-term high temperature events.


Coral Reefs ◽  
2014 ◽  
Vol 34 (2) ◽  
pp. 471-478 ◽  
Author(s):  
E. S. Woolsey ◽  
S. A. Keith ◽  
M. Byrne ◽  
S. Schmidt-Roach ◽  
A. H. Baird

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