Search results for "tuhohyönteiset"
showing 10 items of 10 documents
Complex responses of global insect pests to climate warming
2020
Although it is well known that insects are sensitive to temperature, how they will be affected by ongoing global warming remains uncertain because these responses are multifaceted and ecologically complex. We reviewed the effects of climate warming on 31 globally important phytophagous (plant‐eating) insect pests to determine whether general trends in their responses to warming were detectable. We included four response categories (range expansion, life history, population dynamics, and trophic interactions) in this assessment. For the majority of these species, we identified at least one response to warming that affects the severity of the threat they pose as pests. Among these insect spec…
Potential Solar Radiation as a Driver for Bark Beetle Infestation on a Landscape Scale
2019
In recent decades, Norway spruce (Picea abies L. Karst.) forests of the High Tatra Mountains have suffered unprecedented tree mortality caused by European spruce bark beetle (Ips typographus L.). Analysis of the spatiotemporal pattern of bark beetle outbreaks across the landscape in consecutive years can provide new insights into the population dynamics of tree-killing insects. A bark beetle outbreak occurred in the High Tatra Mountains after a storm damaged more than 10,000 ha of forests in 2004. We combined yearly Landsat-derived bark beetle infestation spots from 2006 to 2014 and meteorological data to identify the susceptibility of forest stands to beetle infestation. We found that digi…
The Diapause Lipidomes of Three Closely Related Beetle Species Reveal Mechanisms for Tolerating Energetic and Cold Stress in High-Latitude Seasonal E…
2020
During winter insects face energetic stress driven by lack of food, and thermal stress due to sub-optimal and even lethal temperatures. To survive, most insects living in seasonal environments such as high latitudes, enter diapause, a deep resting stage characterized by a cessation of development, metabolic suppression and increased stress tolerance. The current study explores physiological adaptations related to diapause in three beetle species at high latitudes in Europe. From an ecological perspective, the comparison is interesting since one species (Leptinotarsa decemlineata) is an invasive pest that has recently expanded its range into northern Europe, where a retardation in range expa…
Repeated exposure of fluazinam fungicides affects gene expression profiles yet carries no costs on a nontarget pest
2021
Fungicides are used to control pathogenic fungi of crop species, but they have also been shown to alter behavioral, life history and fitness related traits of non-target insects. Here, we tested the fungicide effects on feeding behavior, survival and physiology of the non-target pest insect, the Colorado potato beetle (Leptinotarsa decemlineata). Feeding behavior was studied by a choice test of adult beetles, which were allowed to choose between a control and a fungicide (fluazinam) treated potato leaf. Larval survival was recorded after 24-hour and 72-hour exposure to control and fungicide-treated leaves with two different concentrations. The adults did not show fungicide avoidance behavio…
Ecological and genetic factors contributing to invasion success : the northern spread of the Colorado potato beetle (Leptinotarsa decemlineata)
2008
Sanna Boman tutki väitöskirjassaan koloradonkuoriaisen potentiaalia levitä Suomeen. Hän selvitti kuoriaisten mahdollisuuksia selviytyä alhaisissa lämpötiloissa ja kykyä sopeutua Suomen viileään ilmastoon.Boman havaitsi, että koloradonkuoriaisella on potentiaalia levitä Suomeen pysyvästi, sillä geneettiset tekijät ja Suomen kesälämpötilat eivät rajoita koloradonkuoriaisen selviytymistä pohjoisessa.Koloradonkuoriaisilla on geneettistä vaihtelua elinkiertopiirteissä, kuten kehitysajassa ja koossa, minkä avulla kuoriaiset voivat sopeutua entistä paremmin uusiin olosuhteisiin, esimerkiksi alhaiseen lämpötilaan. Koloradonkuoriaiset pystyvät kehittymään ja selviytymään Suomen normaaleissa kesäolos…
Sublethal Pyrethroid Insecticide Exposure Carries Positive Fitness Effects Over Generations in a Pest Insect
2019
AbstractStress tolerance and adaptation to stress are known to facilitate species invasions. Many invasive species are also pests and insecticides are used to control them, which could shape their overall tolerance to stress. It is well-known that heavy insecticide usage leads to selection of resistant genotypes but less is known about potential effects of mild sublethal insecticide usage. We studied whether stressful, sublethal pyrethroid insecticide exposure has within-generational and/or maternal transgenerational effects on fitness-related traits in the Colorado potato beetle (Leptinotarsa decemlineata) and whether maternal insecticide exposure affects insecticide tolerance of offspring…
Cost of reproduction in a seed beetle : a quantitative genetic perspective
2006
Lisääntymisestä on kustannuksia, jotka ilmenevät lyhentyneenä elinikänä. Elinikä ja lisääntymisestä aiheutuvat kustannukset ovat geenien määräämiä.- Väitöskirjatyössäni tutkin lisääntymisen kustannuksia koirailla. Tutkimuskohteena käytin Callosobruchus maculatus - jyväkuoriaisia, jotka ovat trooppisia papujen tuholaisia. Kyseinen laji on paljon käytetty evoluutioekologian alan mallilaji. Naarailla on tehty runsaasti lisääntymisen kustannustutkimuksia, mutta koirailla vain muutamia tutkimuksia. Perinteisesti on ajateltu, että koiras panostaa lisääntymiseen lähinnä parittelemalla ja luovuttamalla sukusoluissaan geenejään jälkeläisilleen, Satu Paukku kertoo.Tutkimuksissa ilmeni, että koiraille…
Kantojen ja metsänreunan etäisyyden vaikutus kaarnakuoriaisten jakautumiseen hakkuuaukoissa
2017
Viime vuosina kantojen korjuu energiapuuksi on lisääntynyt, mikä vähentää eliöstön monimuotoisuutta hakkuualoilla. Hakkuuaukoille jätetyt kannot tarjoavat resursseja esimerkiksi kaarnakuoriaisille, jotka ovat nilaa syöviä kovakuoriaisia. Kaarnakuoriaiset toimivat tärkeinä lahottajina aloittaen lahotusprosessin, mutta toisaalta ne aiheuttavat myös taloudellisia tappioita vahingoittaessaan metsäteollisuudessa käytettävää puuta. Kantojen jättäminen hakkuuaukolle voi herättää taloudellisesta näkökulmasta huolen, että kaarnakuoriaiset lisääntyvät kantojen myötä myös terveessä pystymetsässä. Tutkimuksessa tavoitteena oli selvittää, houkuttelevatko kannot kaarnakuoriaisia ja vaikuttaako kantojen s…
Eco-physiological aspects of adaptation to seasonal environments : the latitudinal range expansion of the Colorado potato beetle across Europe
2013
Adaptation to stressful environments : invasion success of the Colorado potato beetle (Leptinotarsa decemlineata)
2018
Biological invasions, specifically human-induced dispersals, are one of the major threats to our biodiversity and are predicted to increase. Invasive pests provide an opportunity to study whether adaptation to human-induced environments could promote invasions to other human-induced environments. One major anthropogenic selection pressure is created by pesticides, and pests can be exposed to various pesticides in their native, as well as introduced, ranges. I investigated whether exposure to anthropogenic selection (i.e. insecticides and herbicides) and exposure to multiple anthropogenic stressors selects for higher stress tolerance. I also tested whether parental prolonged diapause or inse…