scholarly journals Effects of climate warming on the pine processionary moth at the southern edge of its range: a retrospective analysis on egg survival in Tunisia

2021 ◽  
Author(s):  
Asma Bourougaaoui ◽  
Christelle Robinet ◽  
Mohamed Lahbib Ben Jamâa ◽  
Mathieu Laparie
Keyword(s):  
Climate Change ◽  
Thermal Sensitivity ◽  
Climatic Variability ◽  
Hatching Rate ◽  
Parasitism Rate ◽  
Egg Survival ◽  
Pine Processionary Moth ◽  
Processionary Moth ◽  
Egg Maturation ◽  
South Tunisia

In recent years, ectotherm species have largely been impacted by extreme climate events, essentially heatwaves. In Tunisia, the pine processionary moth (PPM), Thaumetopoea pityocampa, is a highly damaging pine defoliator, which typically lays eggs in summer. Its geographical range is expanding northwards in Europe while retracting from South Tunisia where summer temperatures can reach extremely high values. In this study, we aimed at exploring the effects of climate change on this species at its southern range edge. We investigated variations of fecundity and causes of egg mortality over time using historical and contemporary collections of egg masses from different Tunisian sites to seek relationships with regional climate change over three decades (1990-2019). Our results suggest negative effects of summer heat on egg survival, reflected in a decrease of hatching rate down to 0% in one site during a heatwave. Such a high hatching failure was found to result from both high egg sterility (our results did not allow distinguishing impeded mating success from failed egg maturation or early death of the embryo) and increased abortion of more developed embryos, but little effects of parasitism rate, thereby suggesting vulnerability to heat during embryonic development. We also observed decreasing female fecundity (i.e., number of eggs laid per female) in regions where data were available both in the 1990s and the 2010s, which was associated with a decrease in parasitism rate, while the climatic variability increased. This study investigated direct hatching failure in nature that may be related to the magnitude of warming in summer. Previous studies have confirmed the thermal sensitivity of early instars of the PPM to temperatures observed in the present work, including one population from South Tunisia. However, further work is required to evaluate the relative importance of warming summers among populations because the risk of heat stress depends on the phenology of sensitive instars, and populations from the warmest areas may not necessarily be the most vulnerable to climate change if they already evolved phenological heat avoidance. In addition to heat-induced mortality, the ultimate fitness of individuals that survive challenging heat stresses during early developmental stages should also be explored to determine potential carry-over effects on subsequent life stages.

Effect of heat waves on embryo mortality in the pine processionary moth

2017 ◽  
Vol 107 (5) ◽  
pp. 583-591 ◽  
Author(s):  
S. Rocha ◽  
C. Kerdelhué ◽  
M.L. Ben Jamaa ◽  
S. Dhahri ◽  
C. Burban ◽  
...  
Keyword(s):  
Development Time ◽  
Heat Waves ◽  
Tunisian Population ◽  
Thaumetopoea Pityocampa ◽  
Egg Survival ◽  
Portuguese Population ◽  
Southern Limit ◽  
Pine Processionary Moth ◽  
Processionary Moth ◽  
Negative Effect

AbstractExtreme climate events such as heat waves are predicted to become more frequent with climate change, representing a challenge for many organisms. The pine processionary moth Thaumetopoea pityocampa is a Mediterranean pine defoliator, which typically lays eggs during the summer. We evaluated the effects of heat waves on egg mortality of three populations with different phenologies: a Portuguese population with a classical life cycle (eggs laid in summer), an allochronic Portuguese population reproducing in spring, and a Tunisian population from the extreme southern limit of T. pityocampa distribution range, in which eggs are laid in fall. We tested the influence of three consecutive hot days on egg survival and development time, using either constant (CT) or daily cycling temperatures (DT) with equivalent mean temperatures. Maximum temperatures (Tmax) used in the experiment ranged from 36 to 48°C for DT and from 30 to 42°C for CT. Heat waves had a severe negative effect on egg survival when Tmax reached 42°C for all populations. No embryo survived above this threshold. At high mean temperatures (40°C), significant differences were observed between populations and between DT and CT regimes. Heat waves further increased embryo development time. The knowledge we gained about the upper lethal temperature to embryos of this species will permit better prediction of the potential expansion of this insect under different climate warming scenarios.

scholarly journals What evidence exists on the impacts of flow variability on fish and macroinvertebrates of temperate floodplain rivers in Central and Western Europe? A systematic map protocol

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Agata Keller ◽  
Somsubhra Chattopadhyay ◽  
Mikołaj Piniewski
Keyword(s):  
Climate Change ◽  
Western Europe ◽  
Climatic Variability ◽  
Grey Literature ◽  
Habitat Type ◽  
Water Diversion ◽  
Systematic Map ◽  
Eligibility Criteria ◽  
Flow Variability ◽  
Floodplain Rivers

Abstract Background Flow variability is considered a fundamental factor affecting riverine biota. Any alterations to flow regime can influence freshwater organisms, and this process is expected to change with the projected climate change. This systematic map, therefore, aims at investigating the impacts of natural (resulting from climatic variability), anthropogenic (resulting from direct human pressure), and climate change-induced flow variability on fish and macroinvertebrates of temperate floodplain rivers in Central and Western Europe. Particular focus will be placed on the effects of extreme low and high discharges. These rare events are known to regulate population size and taxonomic diversity. Methods All studies investigating the effects of flow variability on metrics concerning freshwater fish and macroinvertebrates will be considered in the map, particularly metrics such as: abundance, density, diversity, growth, migration, recruitment, reproduction, survival, or their substitutes, such as biomonitoring indices. Relevant flow variability will reflect (1) anthropogenic causes: dams, reservoirs, hydroelectric facilities, locks, levees, water abstraction, water diversion, land-use changes, road culverts; (2) natural causes: floods, droughts, seasonal changes; or (3) climate change. Geographically, the map will cover the ecoregion of Central and Western Europe, focusing on its major habitat type, namely “temperate floodplain rivers and wetlands”. The review will employ search engines and specialist websites, and cover primary and grey literature. No date, language, or document type restrictions will be applied in the search strategy. We expect the results to be primarily in English, although evidence (meeting all eligibility criteria) from other languages within the study area will also be included. We will also contact relevant stakeholders and announce an open call for additional information. Eligibility screening will be conducted at two levels: title and abstract, and full text. From eligible studies the following information will be extracted: the cause of flow variability, location, type of study, outcomes, etc. A searchable database containing extracted data will be developed and provided as supplementary material to the map report. The final narrative will describe the quantity and key characteristics of the available evidence, and identify knowledge gaps and knowledge clusters, i.e. subtopics sufficiently covered by existing studies allowing full systematic review and meta-analysis.

scholarly journals Rethinking Climate, Climate Change, and Their Relationship with Water

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 849
Author(s):  
Demetris Koutsoyiannis
Keyword(s):  
Climate Change ◽  
Climatic Variability ◽  
Main Element ◽  
The Political ◽  
Real World Data ◽  
Modern Times ◽  
External Agent ◽  
Historical Investigation ◽  
Definition Of ◽  
Water Issues

We revisit the notion of climate, along with its historical evolution, tracing the origin of the modern concerns about climate. The notion (and the scientific term) of climate was established during the Greek antiquity in a geographical context and it acquired its statistical content (average weather) in modern times after meteorological measurements had become common. Yet the modern definitions of climate are seriously affected by the wrong perception of the previous two centuries that climate should regularly be constant, unless an external agent acts upon it. Therefore, we attempt to give a more rigorous definition of climate, consistent with the modern body of stochastics. We illustrate the definition by real-world data, which also exemplify the large climatic variability. Given this variability, the term “climate change” turns out to be scientifically unjustified. Specifically, it is a pleonasm as climate, like weather, has been ever-changing. Indeed, a historical investigation reveals that the aim in using that term is not scientific but political. Within the political aims, water issues have been greatly promoted by projecting future catastrophes while reversing true roles and causality directions. For this reason, we provide arguments that water is the main element that drives climate, and not the opposite.

Non-host volatiles mediate associational resistance to the pine processionary moth

Oecologia ◽  
2011 ◽  
Vol 166 (3) ◽  
pp. 703-711 ◽  
Author(s):  
H. Jactel ◽  
G. Birgersson ◽  
S. Andersson ◽  
F. Schlyter
Keyword(s):  
Associational Resistance ◽  
Host Volatiles ◽  
Pine Processionary Moth ◽  
Processionary Moth

Interactions between pupae of the pine processionary moth (Thaumetopoea pityocampa) and parasitoids in a Pinus forest

2015 ◽  
Vol 105 (5) ◽  
pp. 621-628 ◽  
Author(s):  
C.P. Bonsignore ◽  
F. Manti ◽  
E. Castiglione
Keyword(s):  
Environmental Effects ◽  
Morphological Traits ◽  
External Factors ◽  
Thaumetopoea Pityocampa ◽  
Parasitoid Species ◽  
Pine Processionary Moth ◽  
Processionary Moth ◽  
The Impact ◽  
Positive Effect ◽  
Forest Lepidoptera

AbstractParasitoids are significant enemies of many economically important insects and there is some evidence to suggest that their actions have a role in terminating the outbreaks of forest Lepidoptera populations. In this study, we examined the impact of parasitoids on the pupae of the pine processionary moth, and highlighted the presence of several parasitoid species for this developmental stage. A higher rate of parasitism was found when the pupal density in the soil was reduced, but the rate of parasitism was not influenced by pupal morphological traits or by the presence or absence of a cocoon around a pupa. Of the external factors examined, a delay in the time of descent of larvae from the trees had a positive effect on the level of parasitism. Observational data indicated that dipteran and hymenopteran were the most abundant parasitoids to emerge from moth pupae. Our study highlights the complexity of the parasitoid–host dynamics, and stresses the importance of carefully determining environmental effects on host–parasitoid relations.

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