Recently, the cold resistance becomes a common topic in scientific articles. If we focus on order Heteroptera, we can find a lot of studies dealing with the cold resistance or with the supercooling point (SCP) and also with the factors that influence them. According to the general rule, the acclimation at low temperatures increases the cold resistance. Therefore, the main goal of this thesis is to find out, whether the acclimation also increases the cold resistance of the water cricket Velia caprai Tamanini, 1947 (Veliidae), with the intention to measure SCP of the water crickets depending on the acclimation temperature and the length of exposure. Due to the high mortality (the 284 individuals remained alive of total 1300) and due to the technical difficulties in measuring of SCP (measured only 36 individuals) it was necessary to modify the original goal of the thesis. The new goal was to test the influence of acclimation (during one month vs. one week) and the influence of different temperatures (0°C, 5°C, 10°C) on SCP of V. caprai. The individuals used for this measurement were collected during the year 2010 and in March 2011. The results of this thesis did not confirm the hypothesis that the acclimation at low temperatures increases the cold resistance. The individuals who were acclimated at a higher temperature have the values of SCP demonstrably lower than the individuals who were acclimated at low temperatures. The individuals who overwinter for the first time have arguably higher cold resistance than the individuals who overwinter for the second time. Probable cause of these results is the fact that the water cricket V. caprai does not start with diapause in the fall but it overwinters in quiescence.

The stink bugs are pests of soybean, corn, wheat and other crops. Economically, its management and key knowledge and behavior of their populations are needed to plan effective of action. The objective of this research was to investigate the occurrence, spatial-temporal distribution and population fluctuations of species of stink bugs in the succession of crops. The study was conduced during 12/2007 to 11/2009 on Jóia, RS, Brazil, in a commercial farming area of 162ha with no-tillage system, and center pivot irrigation (92ha) and adjacent areas (70ha). In the first year of study, 2007/08, 41ha pivot was planted with soybean [Glycine max (L.) Merrill] and 51ha, with corn (Zea mays L.), while in the offseason of 2008, with 41ha oat (Avena strigosa Schreb) associated with wild radish (Raphanus sativus L.) in succession to soybean and 51ha with oat in corn stubble. In the second year, the 2008/09 crop was planted soybeans in the entire pivot area (92ha) and adjacent areas (70ha). Already in the 2009 offseason, was season black oat (Avena sativa L.) in succession to soybean and wheat (Triticum aestivum L.) in the areas adjacent. Through the Campeiro CR-6® Software was generated a thematic map of the research and divided into regular grid of 63 cells 2.5 ha and their centers constituted the sampling points. The points were located with GPS. Samplings were made fortnightly in 2m², surveying vegetation, straw, crop residues and soil surface. Was noted the number of bugs nymphs from second instars and adults. The species were confirmed in the laboratory of Integrated Pest Management (LabMIP).To analyze the occurrence of population were used statistical series of geographical and temporal, is drawing up tables of frequency distribution of the population for each culture of the pivot, surrounding areas and places of refuge. The data were statistically analyzed by software BioEstat5®. We applied the binomial probability test between the populations of stink bugs on crops and surrounding areas to verify the differences in � 0.05 level of significance. To analyze spatial and temporal distribution, we used the CR-Campeiro6 ® generating digital maps of population distribution of stink bugs. To analyze the fluctuation, graphics were elaborated through the Excel® Software. Was quantified the populations of Euschistus heros (Fabricius, 1798), Dichelops furcatus (Fabricius, 1775), Piezodorus guildinii (Westwood, 1837), Nezara viridula (Linnaeus, 1758) and Edessa meditabunda (Fabricius, 1794). During the two years of study, E. heros and D. furcatus was the species most frequent in soybeans. D. furcatus is more common in corn, wheat and oats. P. guildinii occurs frequently in soybeans. Populations of N. viridula and E. meditabunda are less frequent. In the offseason, the bugs shelter in the trash, weeds, wheat, oats, turnip and migrate to the edge of forest vegetation and wetland. Populations of stink occur more frequently in soybean at stage R7.1 and R9, corn in summer and winter grasses. The location of the beginning of planting determines the distribution of the population. Areas sown late have high immigrant populations of bugs crop more developed or already picked. The occurrence, spatial-temporal distribution and population dynamics of stink bugs vary each year, influenced by soybeans, corn, wheat, oat, turnip, the crop successions, culture adjacent, alternative host plant, trash, weeds and management operations. / Os percevejos pentatomídeos são pragas de soja, milho, trigo e outras culturas. Economicamente, seu manejo é fundamental e o conhecimento do comportamento de suas populações é necessário para planejar medidas de ação eficientes. O objetivo desta pesquisa foi verificar a ocorrência, distribuição espaço-temporal e flutuação da população de espécies de percevejos, nas sucessões de cultivos e áreas adjacentes. O estudo foi realizado entre 12/2007 e 11/2009 no município de Jóia, RS, Brasil, em uma área agrícola comercial de 162ha com sistema de plantio direto e irrigação via pivô central (92ha) e áreas adjacentes (70ha). No primeiro ano de estudo, safra 2007/08, 41ha do pivô foi cultivado com soja [Glycine max (L.) Merril] e 51ha, com milho (Zea mays L.); já na entressafra de 2008, 41ha com aveia preta (Avena strigosa Schreb) associada com nabo forrageiro (Raphanus sativus L.) em sucessão à cultura de soja e 51ha com aveia preta na palhada do milho. No segundo ano, safra 2008/09, foi cultivada soja na totalidade da área do pivô (92ha) e áreas adjacentes (70ha). Já na entressafra 2009, foi cultivada aveia branca (Avena sativa L.) e preta em sucessão à soja e trigo (Triticum aestivum L.) nas áreas adjacentes do pivô. Através do programa CR-Campeiro 6® foi gerado um mapa temático da área de pesquisa e dividida em grade regular de 63 células de 2,5ha e seus centros constituíram-se nos pontos amostrais. Os pontos foram localizados com sistema de posicionamento global (GPS). Foram realizadas amostragens quinzenalmente em 2m², nas culturas, vegetação, palhada, restos de culturas e superfície do solo. Em planilha de campo anotou-se o número de percevejos adultos e ninfas a partir do segundo ínstar. As espécies foram confirmadas no laboratório de Manejo Integrado de Pragas (LabMIP). Para analisar a ocorrência populacional foram utilizadas séries estatísticas do tipo geográfica-temporal, elaborando-se tabelas de distribuição de frequências da população para cada cultura do pivô, áreas adjacentes e locais de refúgio. Os dados foram submetidos à análise estatística através do programa BioEstat 5®. Aplicou-se o teste binomial de probabilidade entre as populações de percevejos nas culturas e áreas adjacentes para verificar diferenças em nível de 5% de significância. Para analisar distribuição espaço-temporal utilizou-se o programa geoestatístico CR-Campeiro6® gerando mapas digitais de distribuição da população de percevejos. Para analisar a flutuação populacional, foram elaborados gráficos através do programa Excel®. Foram estudadas as populações de Euschistus heros (Fabricius, 1798), Dichelops furcatus (Fabricius, 1775), Piezodorus guildinii (Westwood, 1837), Nezara viridula (Linnaeus, 1758) e Edessa meditabunda (Fabricius, 1794). As espécies de maior ocorrência na safra foram E. heros e D. furcatus, concentrando-se na soja. D. furcatus é mais frequente nas culturas de milho, trigo e aveia. P. guildinii, ocorre com maior frequência na soja. Populações de N. viridula e E. meditabunda são menos freqüentes. Na entressafra, os percevejos abrigam-se na palhada, plantas espontâneas, trigo, aveia, nabo forrageiro e migram para vegetações de borda de mato e banhado. As populações de pentatomídeos ocorrem com maior frequência na cultura de soja nos estádios R7.1 e R9, no milho no verão e em gramíneas no inverno. O local de início do plantio determina a distribuição da população de percevejos. Áreas semeadas tardiamente apresentam elevadas populações de percevejos emigrantes de cultivos mais desenvolvidos ou já colhidos. A ocorrência, distribuição espaço-temporal e flutuação populacional de percevejos variam anualmente, influenciadas pelas sucessões de culturas de soja, milho, trigo, aveia, nabo forrageiro, cultura adjacente, vegetação de refúgio, palhada, plantas daninhas e operações de manejo.

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Building design, maintenance, and management can have significant impacts on accessibility and suitability for pest species. The brown marmorated stink bug, Halyomorpha halys (Stål), causes household nuisance pest problems because of its habit of using human homes as winter refuges. Studies were conducted to understand behaviors and characteristics relevant to this problem, including response to gravity, ability to pass through openings, responses to heat, and mortality estimations in wall assemblies. In the lab, winter shelter seeking bugs were shown to exhibit upward movement, and field observations of bugs on building exteriors gave similar results. In experiments testing the size limits on openings through which bugs could pass, height limited tests excluded most females at 4 mm, and all bugs at 3 mm. Pronotum width limited tests excluded most females at 8 mm and nearly all bugs at 7 mm. Accompanying measurements of over 900 bugs found an average female pronotum width of 8.33 mm and height of 4.03 mm, and male pronotum width of 7.47 mm and height of 3.50 mm, with minimum sizes indicating that only a small percentage of bugs will pass the smallest openings tested. Heat response experiments of shelter seeking bugs were first piloted outdoors, and then modified to be a forced choice indoor test. In outdoor tests on a flat plane wall section with alternating heated sections, bugs did not respond to thermal contrast but rather immediately walked off of the wall. In the indoor forced choice test, a box of four cavity walls was used. Bugs did not respond to the heated sections in either the adjacent or opposite configuration. Thermal simulation modeling was used to evaluate the possible effects of varying wall assembly materials and configurations on cold-related mortality of bugs overwintering in the cavity space behind cladding. Simulation results indicated that bugs electing to overwinter in the space between cladding and sheathing were at risk of freezing deaths, with mortality expectations increasing in better insulated buildings. The results of these studies will inform future control measures and impact studies in buildings. / Ph. D.

The western toad (Anaxyrus boreas, formerly Bufo boreas) is one of many amphibian species considered to be at risk of extinction (COSEWIC status is Special Concern). I examined habitat use patterns of the western toad using several methods to gain a better understanding of its habitat requirements. I examined the relationship between relative abundance of the western toad and two sympatric amphibian species (wood frog, Lithobates sylvaticus; and boreal chorus frog, Pseudacris maculata) and habitat features at eight scales of spatial extent at 24 wetlands in the Lake Utikuma region of Alberta, Canada. I radio-tracked adult western toads in three study areas in the Aspen Parkland and Boreal regions of north-central Alberta to examine 1) whether patterns of habitat selection change with different scales of spatial extent, spatial resolution, habitat composition, temporal period, and between males and females during the active period, 2) habitat used for hibernation, and 3) factors influencing the timing and nature of movements to hibernation sites. I found that the abundance of the three amphibian species was best described at different spatial extents and was related to the biology of each species. Resource Selection Function (RSF) models, created using radio-telemetry data, indicated that habitat selection was scale-dependent for western toads; differences in selection were observed among study designs, study areas, time periods, and sexes. Predictive ability did not differ significantly among study designs. However, models that were created using a fine-grained map and home-range spatial extent generally produced models with greater predictive ability than models using a coarse-grained map or population-range extent. During the active season toads selected open habitat types such as wet shrub, disturbed grass, and crop/hay fields. Western toads hibernated terrestrially in pre-existing tunnels and the majority of toads hibernated in forest stands dominated by spruce. Toads used hibernation sites 1461936 m from breeding ponds and 68% of hibernacula were communal. Arrival at and entry into hibernation sites was influenced by temperature and/or day length; larger toads moved to hibernation sites later in the year. My research results can be used to identify and protect habitat for western toads in Canada. / Environmental Biology and Ecology

No description available.

Les changements climatiques altèrent la phénologie des organismes, c’est-à-dire la succession dans le temps des éléments de leur cycle de vie. L’expression de la diapause chez les insectes, soit l’arrêt de développement permettant de survivre aux dégradations saisonnières de l’environnement biotique et abiotique, est en particulier affectée. Cette thèse aborde différents facteurs environnementaux agissant sur les stratégies saisonnières des parasitoïdes de pucerons du genre Aphidius. Dans les agro-systèmes céréaliers de l’ouest de la France, les communautés d’hôtes et de parasitoïdes ont changé rapidement au cours de la dernière décennie. Ainsi, plusieurs espèces de parasitoïdes n’entrent plus qu’en faible proportion en diapause, dû à l’augmentation des températures, à la baisse du nombre de jours de gel et à la présence accrue de leurs hôtes pendant l’hiver ; ces pressions de sélection agissent sur les seuils d’entrée diapause. Les parasitoïdes présentent des ajustements plastiques de leur réponse aux stimuli environnementaux qui induisent la diapause. Ils y entrent en plus forte proportion s’ils se développent dans des morphes de pucerons sexués (annonciateurs de ressources limitées) que dans des hôtes asexués, ce qui souligne la co-évolution de leurs cycles de vie. Cette plasticité s’avère également transgénérationnelle puisque la compétition entre femelles induit la diapause estivale chez leurs descendants. De plus, l’incidence de la diapause hivernale augmente après plusieurs générations de parasitoïdes soumises aux mêmes conditions. Les adaptations locales des parasitoïdes aux nouvelles conditions environnementales mènent à la perte d’expression de la stratégie de diapause – qui comporte des coûts écologiques et physiologiques – au profit de stratégies hivernales d’activité à l’état adulte. La modification de l’activité-densité des espèces au sein des communautés de pucerons-(hyper)parasitoïdes, due aux changements de stratégie d’hivernation, pourrait bouleverser l’équilibre des réseaux trophiques et altérer positivement ou négativement l’efficacité du service écosystémique de lutte biologique. / Climate changes alter the phenology of organisms, i.e. the succession over time of the elements of their life-cycle. Diapause expression in insects – that is, the developmental arrest allowing survival to seasonal degradations in the biotic and abiotic environment – is particularly affected. This thesis addresses the existence of different environmental factors acting on the seasonal strategies of Aphidius aphid parasitoids. In cereal agro-systems of western France, host and parasitoid communities have changed rapidly over the past decade. Hence, some parasitoid species enter diapause at low levels due to temperature increase, decrease in frost events and the presence of their hosts during winter, which impose selection on diapause induction thresholds. Parasitoids show plastic adjustments of their response to environmental stimuli inducing diapause. They enter diapause at higher proportion if they develop in sexual morphs of aphids (which inform for upcoming limited resources) than in asexual hosts, which underlines the co-evolution of their life-cycles. Transgenerational plasticity is also involved in these responses since maternal competition induces summer diapause in their offspring. Moreover, winter diapause incidence increases after some parasitoid generations experience the same environmental conditions. Local adaptations of parasitoids to new environmental conditions lead to a loss of diapause expression – which involves ecological and physiological costs – to the benefit of adult overwintering strategies. Modifications in species activity-density within aphids-(hyper)parasitoids communities, due to changes in overwintering strategies, could affect food-webs’ stability and alter positively or negatively the efficiency of biological pest control.

Climate change is warming the North and exposing its immense carbon stores not only to wildfire disturbances, but overwintering, or zombie, fire. These remnants of summer fires can spend months smouldering under the surface, hidden under the protection of layers of snow, burning through immense amounts of carbon, which is then released into the atmosphere, further exacerbating climate change. In order to prevent these potential megafires, areas that are prone to their occurrence need to be identified so that detection and management protocols can be put into place. Using a GIS approach, this paper attempts to identify any areas in the northern circumpolar country of Sweden that are currently susceptible to zombie fire and any that might be susceptible in 2050 using a RCP8.5 scenario projection. Based on spatial and climatic variables, the results found 88 km2 of land that is currently susceptible, 20.19 km2 of which is most prone due to mild winter and spring conditions. In the 2050 projection, most regions were found to have a decrease in susceptibility due to warmer winters reducing snow coverage. However, three counties in the north were found to have an increased susceptibility due to the earlier arrival of spring. Climate projections still contain uncertainties and how the annual precipitation of Sweden will be affected by climate change varies greatly between models, which naturally effects the likelihood of future wildfires, and ensuing zombie fires. There is a need for more research surrounding zombie fires, particularly with regards to snow depth and coverage and how this affects the mechanisms of smouldering combustion and smouldering to flaming transition. This paper is an example of how regions can be assessed for hazardous events if they have some spatial and temporal predictability. / Klimatförändringarna värmer upp Norden och utsätter dess enorma kolsänkor inte bara för skogsbrandstörningar utan också för övervintrande (eller zombie-) bränder. Dessa gamla sommarbränder kan spendera månader under ytan, gömda under skydd av snötäcke, brännande enorma mängder kol, som sedan släpps ut i atmosfären, vilket ytterligare förvärrar klimatförändringarna. För att förhindra dessa potentiella megaeldar (eng. megafires) måste områden med benägenhet för dess inträffande identifieras så att detektions- och hanteringsprotokoll kan införas. Med hjälp av ett GIS-tillvägagångssätt försöker denna uppsats att identifiera alla områden i Sverige som för närvarande är i riskzonen för zombiebränder och alla områden som kan vara i riskzonen 2050 med hjälp av en RCP8.5-scenarioprojektion. Baserat på rumsliga och klimatvariabler fann resultaten att 88 km2 mark för närvarandet är i riskzonen, varav 20,19 km2 är mest benägen på grund av milda vinter- och vårväder. I 2050-projiceringen visade sig de flesta regioner ha en minskad risk på grund av varmare vintrar som minskade snötäckningen. Men tre län i norr hade en ökad risk på grund av vårens tidigare ankomst. Klimatprognoser innehåller fortfarande osäkerheter och hur den årliga nederbörden i Sverige kommer att påverkas av klimatförändringen varierar kraftigt mellan olika modeller, vilket naturligtvis påverkar sannolikheten för framtida skogsbränder och således zombiebränder. Det finns ett behov av mer forskning kring zombiebränder, särskilt med avseende på snödjup och täckning och hur detta påverkar mekanismerna för pyrande förbränning och pyrande-till-flammande-övergång. Denna uppsats är ett exempel på hur regioner kan utvärderas för faror om de har viss rumslig och tidsmässig förutsägbarhet.

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