Search results for "hyönteiset"
showing 10 items of 56 documents
Effects of a glyphosate-based herbicide on survival and oxidative status of a non-target herbivore, the Colorado potato beetle (Leptinotarsa decemlin…
2018
Abstract Glyphosate is the globally most used herbicide against a wide range of weeds. Glyphosate has been considered safe to animals as it mainly targets physiological pathways in plants. However, recent toxicological studies have revealed that glyphosate can cause various toxic effects also on animals. In this study, we investigated the direct toxic effects of a glyphosate-based herbicide (GBH, Roundup® Bio) on 1) survival and 2) oxidative status of a non-target herbivore by using Colorado potato beetles (Leptinotarsa decemlineata), originating from Poland and USA, as model species. Larvae were randomly divided into three groups: 1) high concentration (100% Roundup Bio, 360 g/l), 2) low c…
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…
Different trophic positions among social vespid species revealed by stable isotopes
2021
The social vespid wasps are common insect predators and several species behave in unison in the same biotopes. It is commonly accepted that social wasps are mainly opportunistic generalist predators without differences in prey selection and hence they compete for the same food resources. Trophic positions of six vespid wasp species and their potential prey from four sites in Finland and one in the UK were evaluated using carbon and nitrogen stable isotopes (δ13C and δ15N). The difference in isotope values indicated different trophic positions among species. In general, Dolichovespula spp. showed higher δ15N values than Vespula spp., which suggests that Dolichovespula forage on higher trophi…
Automatic image-based identification and biomass estimation of invertebrates
2020
1. Understanding how biological communities respond to environmental changes is a key challenge in ecology and ecosystem management. The apparent decline of insect populations necessitates more biomonitoring but the time-consuming sorting and expert-based identification of taxa pose strong limitations on how many insect samples can be processed. In turn, this affects the scale of efforts to map and monitor invertebrate diversity altogether. Given recent advances in computer vision, we propose to enhance the standard human expert-based identification approach involving manual sorting and identification with an automatic image-based technology. 2. We describe a robot-enabled image-based ident…
Effects of landscape composition on hoverflies (Diptera: Syrphidae) in mass-flowering crop fields within forest-dominated landscapes
2022
Agricultural intensification has led to structurally simplified landscapes with reduced and fragmented resources for farmland insects. However, studies on the effects of landscape composition on farmland insects have mainly been performed in areas dominated by open arable land and semi-natural grasslands, while studies from forest-dominated landscapes are scarce. This research examined the effects of landscape composition on hoverfly species richness and abundance in arable land in boreal forest-dominated landscapes. Hoverflies were sampled in 22 mass-flowering caraway (Carum carvi) fields in Central Finland using pan traps. The effects of landscape composition on species richness and abund…
Immunological priming in the wood tiger moth (Parasemia plantaginis)
2014
Hyönteisiin lukeutuu monia merkittäviä tuholaisia, taudinvälittäjiä ja hyödyllisiä lajeja, minkä takia hyönteisten taudit, taudinaiheuttajat ja immuunipuolustus ovat ekologisesta, ekonomisesta ja lääketieteellisestä näkökulmasta tärkeitä tutkimuskohteita. Viimeaikaiset tutkimukset paljastavat hyönteisten ja muiden selkärangattomien immuunijärjestelmien pystyvän erikoistumaan ja luomaan pitkäkestoista immuniteettia. Jälkimmäinen ilmiö tunnetaan tieteellisissä artikkeleissa nimellä ”immunological priming”, jonka voisi kääntää suomeksi esimerkiksi ”immuunipohjustukseksi”. Immuunipohjustus on muistinkaltaista vastustuskykyä, joka auttaa elimistöä puolustautumaan tehokkaammin toistuvia tartuntoj…
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…
Juveniilihormonin vaikutus munantuotantoon ja seksuaaliseen antagonismiin koloradonkuoriaisilla
2012
Hormonitoiminta on yksi eliöiden säätelyjärjestelmistä. Hyönteisillä keskeisessä osassa hormonisäätelyä ovat juveniilihormonit (JH). Niiden määrä yksilöiden elimistössä säätelee monia asioita yksilöiden kehityksestä lisääntymistoimintoihin. Juuri tehokas lisääntyminen onkin eliöiden tärkeimpiä tehtäviä. Hormonitoiminta pitää yllä evoluution myötä eri lajeille ja lajiryhmille kehittyneitä erilaisia lisääntymisstrategioita: jotkin lisääntyvät harvakseltaan mutta huolehtivat poikasistaan, toiset tuottavat paljon jälkeläisiä, jotka ne jättävät selviämään yksin. Sukupuolten välillä on kuitenkin eroja optimaalisessa lisääntymisstrategiassa. Naaraat joutuvat kuluttamaan jälkeläisten tuottamiseen k…
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…