18 research outputs found
Hoplothrips polysticti (Thysanoptera) on the wood-rotting polypore Trichaptum abietinum infesting dead Picea abies in Norway
The fungivorous thrips Hoplothrips polysticti has previously been reported only from Scotland and Sweden. During a survey in forests of different ages in southeastern Norway, the thrips species was found to be common in dead Picea abies infested by Trichaptum abietinum, especially in a semi-old forest. Hoplothrips unicolor was also recorded for the first time in Norway. The occurrence of H. polysticti is discussed in relation to the age of the forests, and to the biochemical interference between fungi impacting the nutrient quality for the thrips. H. polysticti is proposed as a vector for T. abietinum
Identification of adult males and females of Hoplothrips species (Thysanoptera: Tubulifera) known from Norway, and some deductions on their life history
The presence of multiple phenological forms has previously made adults of Hoplothrips species difficult to identify. We present a set of diagnostic metric characters by which the 8 species recorded from Norway can be recognised. Some biological interpretations are also given
Thrips (Thysanoptera) from dead aspen (Populus tremula) trees in Eastern Finland
Thrips were collected from dead aspens (Populus tremula) using trunk-window traps at two forest areas in Eastern Finland during 2001 and 2002.We collected 156 individuals of 23 species (15 Terebrantia; 8 Tubulifera). Four of the species – all Tubulifera – were previously unknown from Finland, and two unknown from Fennoscandia, indicating that the thrips fauna of this area is poorly known. Three of these species, Hoplothrips carpathicus Pelikán, Liophloeothrips glaber Priesner and L. hungaricus (Priesner) are fungivores, while Lispothrips crassipes (Jablonowski) is an arboreal herbivore. The species assemblages of the study areas are compared and a list presented of all species collected
Distribution and Prolonged Diapause of the Rowan Seed Predators Argyresthia conjugella (Lepidoptera: Yponomeutidae) and Megastigmus brevicaudis (Hymenoptera: Torymidae) and their Parasitoids in Norway
The seed predator Argyresthia conjugella Zeller has rowan as its preferred host plant. In years of poor fruiting in rowan, it oviposits on apples. To improve the knowledge of this apple pest, rowanberries were collected from localities all over Norway from 1971 to 1985, and seed predators and their parasitoids were allowed to emerge for up to five years. Two species of seed predators, A. conjugella and Megastimus brevicaudis Ratzeburg, and seven species of parasitic Hymenoptera were common. The distribution of these species is shown on EIS (European Invertebrate Survey) maps of Norway. The biology of the parasitoids is summarized based on the published literature and their behavior during emergence. The tendency for delayed emergence, which is an indication of prolonged diapause, was more pronounced in M. brevicaudis than in A. conjugella, the former appearing in all five years. Five of the parasitoids also delayed their emergence, and three of them to a high degree, up to five years. Prolonged diapause must be taken into account in studies of rowanberry insect guilds.publishedVersio
Attractive plant volatiles as a control method against apple fruit moth (Argyresthia conjugella Zell.)?
Apple fruit moth, Argyresthia conjugella Zell. (Lepidoptera: Argyresthiidae), is the most important
pest of apples in Scandinavia. In years when its primary host, rowan (Sorbus aucuparia L.), has little
or no berries for egglaying, female A. conjugella fly into apple orchards to lay their eggs. In some
years the entire apple crop can be destroyed. Volatiles from apples and rowan have been collected
and identified. In GC-EAD tests females have responded to several compounds found in both
rowan and apple. Some of these compounds were used in field trapping tests during 2002, and a
mixture of two compounds trapped significantly more females and males compared to control traps.
However, field trapping results from 2003 indicate that the two-compound blend seem to trap insects
too late in the season to prevent egglaying in apples. Several new compounds were also
tested in 2003, and some of these gave promising results. The results will be discussed in relation
to use attractive plant volatiles as a control method against A. conjugella females
Rognebærmøll - en sulten flyktning i eplehagen
Det hender at det er mark i eplene. Som oftest er det larven til rognebærmøll som er på ferde. Rognebærmøll er en liten sommerfugl som har fått navnet sitt fordi den har rogn som vertplante. I enkelte år er det lite bær på rogna og møllet må ta til takke med eple som nødproviant. Bioforsk har siden 1980-tallet beregnet angrepsfare av rognebærmøll for Norges epledyrkere. Disse prognosene har mer enn halvert antall sprøytinger i eple, til kun de årene det meldt om angrep. I tillegg har en temperaturmodell økt presisjonen på varslingen slik at gjentatte sprøytinger er minimert. Prognoser og modeller kan imidlertid melde om angrep uten at det slår til. Vi har utviklet et luktstoff som kan bøte på dette. Lukten lokker rognebærmøllen i feller når de flyr inn i eplehagen. Overvåkning med slike feller kan redusere antall sprøytinger med ytterligere 50 – 80 prosent
Moth species richness and diversity decline in a 30‑year time series in Norway, irrespective of species’ latitudinal range extent and habitat
Introduction Insects are reported to be in decline around the globe, but long-term datasets are rare. The causes of these trends are elusive, with changes in land use and climate among the top candidates. Yet if species traits can predict rates of population change, this can help identify underlying mechanisms. If climate change is important, for example, high-latitude species may decline as temperate species expand. Land use changes, however, may impact species that rely on certain habitats. Aims and methods We present 30 years of moth captures (comprising 97,032 individuals of 808 species) from a site in southeast Norway to test for population trends that are correlated with species traits. We use time series analyses and joint species distribution models combined with local climate and habitat data. Results and discussion Species richness declined by 8.2% per decade and total abundance appeared to decline as well (−9.4%, p = 0.14) but inter-annual variability was high. One-fifth of species declined, although 6% increased. Winter and summer weather were correlated with annual rates of abundance change for many species. Opposite to general expectation, many species responded negatively to higher summer and winter temperatures. Surprisingly, species’ northern range limits and the habitat in which their food plants grew were not strong predictors of their time trends or their responses to climatic variation. Complex and indirect effects of both land use and climate change may play a role in these declines. Implications for insect conservation Our results provide additional evidence for long-term declines in insect abundance. The multifaceted causes of population changes may limit the ability of species traits to reveal which species are most at risk.publishedVersio
Fungal diseases, insects, mites and disorders in Norwegian fir plantations for bough- and Christmas tree production
Denne fotopresentasjon er utarbeidd for at rettleiarar og dyrkar lettare skal kunna identifi sera eventuelle skadar på edelgran i klyppegrønt- og juletrefelt. Nummera nedst på kvar side viser til ei liste på side 33 over aktuell litteratur som er publisert ved Bioforsk Plantehelse. Der vil ein kunna fi nna utfyllande opplysningar om dei ulike skadegjerarane.Fungal diseases, insects, mites and disorders in Norwegian fir plantations for bough- and Christmas tree productionpublishedVersio
Temporal changes in personal activity intelligence and the risk of incident dementia and dementia related mortality: A prospective cohort study (HUNT)
Background: The Personal Activity Intelligence (PAI) translates heart rate during daily activity into a weekly score. Obtaining a weekly PAI score ≥100 is associated with reduced risk of premature morbidity and mortality from cardiovascular diseases. Here, we determined whether changes in PAI score are associated with changes in risk of incident dementia and dementia-related mortality.
Methods: We conducted a prospective cohort study of 29,826 healthy individuals. Using data from the Trøndelag Health-Study (HUNT), PAI was estimated 10 years apart (HUNT1 1984-86 and HUNT2 1995-97). Adjusted hazard-ratios (aHR) and 95%-confidence intervals (CI) for incidence of and death from dementia were related to changes in PAI using Cox regression analyses.
Findings: During a median follow-up time of 24.5 years (interquartile range [IQR]: 24.1-25.0) for dementia incidence and 23.6 years (IQR: 20.8-24.2) for dementia-related mortality, there were 1998 incident cases and 1033 dementia-related deaths. Individuals who increased their PAI score over time or maintained a high PAI score at both assessments had reduced risk of dementia incidence and dementia-related mortality. Compared with persistently inactive individuals (0 weekly PAI) at both time points, the aHRs for those with a PAI score ≥100 at both occasions were 0.75 (95% CI: 0.58-0.97) for incident dementia, and 0.62 (95% CI: 0.43-0.91) for dementia-related mortality. Using PAI score <100 at both assessments as the reference cohort, those who increased from <100 at HUNT1 to ≥100 at HUNT2 had aHR of 0.83 (95% CI: 0.72-0.96) for incident dementia, and gained 2.8 (95% CI: 1.3-4.2, P<0.0001) dementia-free years. For dementia-related mortality, the corresponding aHR was 0.74 (95% CI: 0.59-0.92) and years of life gained were 2.4 (95% CI: 1.0-3.8, P=0.001).
Interpretation: Maintaining a high weekly PAI score and increases in PAI scores over time were associated with a reduced risk of incident dementia and dementia-related mortality. Our findings extend the scientific evidence regarding the protective role of PA for dementia prevention, and suggest that PAI may be a valuable tool in guiding research-based PA recommendations.
Funding: The Norwegian Research Council, the Liaison Committee between the Central Norway Regional Health Authority and Norwegian University of Science and Technology (NTNU), Trondheim, Norway.The Norwegian Research Council, the Liaison Committee between the Central Norway Regional Health Authority and Norwegian University of Science and Technology (NTNU), Trondheim, Norway.publishedVersio
Completing Linnaeus's inventory of the Swedish insect fauna: Only 5,000 species left?
Despite more than 250 years of taxonomic research, we still have only a vague idea about the true size and composition of the faunas and floras of the planet. Many biodiversity inventories provide limited insight because they focus on a small taxonomic subsample or a tiny geographic area. Here, we report on the size and composition of the Swedish insect fauna, thought to represent roughly half of the diversity of multicellular life in one of the largest European countries. Our results are based on more than a decade of data from the Swedish Taxonomy Initiative and its massive inventory of the country's insect fauna, the Swedish Malaise Trap Project The fauna is considered one of the best known in the world, but the initiative has nevertheless revealed a surprising amount of hidden diversity: more than 3,000 new species (301 new to science) have been documented so far. Here, we use three independent methods to analyze the true size and composition of the fauna at the family or subfamily level: (1) assessments by experts who have been working on the most poorly known groups in the fauna; (2) estimates based on the proportion of new species discovered in the Malaise trap inventory; and (3) extrapolations based on species abundance and incidence data from the inventory. For the last method, we develop a new estimator, the combined non-parametric estimator, which we show is less sensitive to poor coverage of the species pool than other popular estimators. The three methods converge on similar estimates of the size and composition of the fauna, suggesting that it comprises around 33,000 species. Of those, 8,600 (26%) were unknown at the start of the inventory and 5,000 (15%) still await discovery. We analyze the taxonomic and ecological composition of the estimated fauna, and show that most of the new species belong to Hymenoptera and Diptera groups that are decomposers or parasitoids. Thus, current knowledge of the Swedish insect fauna is strongly biased taxonomically and ecologically, and we show that similar but even stronger biases have distorted our understanding of the fauna in the past. We analyze latitudinal gradients in the size and composition of known European insect faunas and show that several of the patterns contradict the Swedish data, presumably due to similar knowledge biases. Addressing these biases is critical in understanding insect biomes and the ecosystem services they provide. Our results emphasize the need to broaden the taxonomic scope of current insect monitoring efforts, a task that is all the more urgent as recent studies indicate a possible worldwide decline in insect faunas