PRNP guided selection against CWD in reindeer – Impact on local and total genetic variation

The emergence of Chronic Wasting Disease (CWD) in Norway poses a significant threat to the populations of free-ranging and semi-domesticated reindeer. Controlling the spread of the disease is of utmost importance, and studies have indicated that different PRNP genotypes give varying levels of sensitivity to CWD in reindeer. Some genotypes offer more protection against the disease, making it desirable for reindeer herders to breed selectively to increase the ratio of CWD resistant genotypes in the populations. In all artificial selection it is important to avoid reducing the genetic variation in the population. To this end it is important to know to what extent genetic variation in the population is associated with the PRNP-genotypes. DNA samples from reindeer were sequenced with Illumina sequencing, followed by alignment and variant calling to generate a set of SNP genetic markers for population structure and variation analysis. Analysis of population structure revealed that individuals with identical PRNP genotypes did not exhibit increased relatedness to each other compared to the rest of the individuals. However, analysis of positions surrounding the PRNP gene indicated that the PRNP genotypes influenced the variation found in the surrounding regions, suggesting the presence of linkage disequilibrium (LD) tied to PRNP alleles. Notably, the A allele, which causes sensitivity to CWD in reindeer, showed less signs of LD compared to the other alleles. This implies that the A allele has less association with specific variants than the other genotypes and could indicate a smaller chance of removing alleles from the population when selecting away from the A allele. However, importantly, as the A allele exhibited the most variation in the regions surrounding the PRNP gene, selectively removing A alleles would reduce the genetic variation in this area. As a high portion of the variants in the positions surrounding the PRNP gene is found together with the A allele this could potentially lead to the loss of additional alleles. As LD was investigated by visually inspecting clustering in MDS plots in this study more specific analysis is needed to conclude the impact of selective breeding against CWD on genetic variation in the area surrounding the PRNP gene. In addition, this pilot study uncovered an important discrepancy. The genotypes identified through PCA amplification and Sanger sequencing differed from those identified through whole-genome Illumina sequencing for nine of the animals. Further investigation is necessary to determine the causes of these inconsistencies

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

Behandling mot hageoldenborre

Planteforsk Plantevernet får mange henvendelser om skade på plen som skyldes hageoldenborre Phyllopertha horticola, årets sommer var intet unntak. Artikkelen tar for seg biologisk bekjempelse av disse skadegjørerne med nematoden Heterorabditis megidis. Det er også en kort beskrivelse om hageoldenborrenes biologi.Behandling mot hageoldenborrepublishedVersio

Plantevern i grøntanlegg. Integrert bekjempelse

Boka Plantevern i grøntanlegg – integrert bekjempelsehører med i en serie om integrert plantevern i forskjellige kulturer. Bøkene er ment som en del av pensum til autorisasjonskurset i handtering og bruk av plantevernmidler. Et mål er å hjelpe plantedyrkeren og gartneren med å utføre en integrert bekjempelse av skadegjørere. Integrert plantevern går ut på å kombinere flere forskjellige bekjempelsestiltak, slik at bruken av kjemiske midler blir minst mulig. Samtidig bør resultatet kvalitetsmessig, innenfor en økonomisk forsvarlig ramme, bli best mulig. For plantekulturene som er beskrevet i de andre bøkene i denne serien, er retningslinjer for integrert plantevern utarbeidet i tråd med Landbruksdepartementets Handlingsplan for redusert risiko ved bruk av plante vernmidler (1998–2002). Integrert plantevern i grøntanlegg er fore løpig et nytt begrep i Norge, men etter hvert som det blir innarbeidet, vil det også kunne komme retningslinjer for integrert plantevern i grøntanlegg. Disse vil danne grunnlaget for en merkeordning som for eksempel planteskoler og anleggsgartnere kan bruke i sin markedsføring. Den som skal kunne utføre integrert bekjempelse, må vite hvordan skadegjørerne ser ut, hvordan deres biologi er og hvilke tiltak som er aktuelle. Denne boka viser frem sentrale skadegjørere i grøntanlegg og planteskoler. Ved omtale av kjemiske plantevernmidler har vi valgt ikke å bruke navn på midlene, fordi slike opplysninger forandrer seg over tid.publishedVersio

Plantevern i grønnsaker. Integrert bekjempelse

I likhet med oss mennesker kan også planter bli sjuke eller på annen måte bli forstyrret i utviklingen. Begge trenger vi de riktige næringsstoffene for å holde oss friske, og vi må ha det riktige miljøet rundt oss. For å unngå sjukdom og andre skader er dessuten forskjellige forsvarsmekanismer viktige. Planter kan forsvare seg med for eksempel torner mot beitende dyr, behåring mot krypende insektlarver eller ved glatte blad som gjør det vanskelig for soppsporer å feste seg. Dessuten inneholder planter spesielle stoffer som kan være direkte giftige mot skadegjørere. Slike stoffer kalles sekundære plantestoffer. En del sekundære plantestoffer benytter vi som plantevernmidler, medisin, krydder eller i parfyme. I naturlige økosystemer vil for eksempel insekter som spiser planter bli spist av rovinsekter eller bli drept av parasitter. Slike naturlige øko - systemer vil være stabile fordi artsmangfoldet er stort. I jordbruket derimot, dyrker vi store arealer med kun én planteart. I tillegg vil plantene som oftest være foredlet for å gi størst mulig spisbar avling. Foredling har ofte gått på bekostning av plantas forsvarsmekanismer. En slik menneskelig påvirkning i naturen får konsekvenser. Vi kan få opptreden av skadegjørere i stort antall. For å kontrollere skadegjørere i landbruket har en tatt i bruk forskjellige kontrolltiltak som for eksempel kjemiske plantevernmidler. I økologisk landbruk og ved integrert plantevern forsøker en å tilnærme seg naturlige økosystemer i åkeren. Dette kan gjøres ved å legge forholdene for nytteorganismer som rovinsekter bedre til rette i åkeren. Hvordan dette gjøres, kan du lese mer om i grunnboka i kapitlet om integrert plantevern. For plantedyrkeren er det viktig å kjenne plantas venner og fiender eller planteskadegjørere og nytteorganismer, for å: • Vite om og når det er nødvendig å sette i verk kontrolltiltak • Sette i verk riktig kontrolltiltak • For å benytte riktig plantevernmiddel om sprøyting blir nødvendigpublishedVersio

Biology of Lysiphlebus fabarum following cold storage of larvae and pupae

Citation: Mahi, H., Rasekh, A., Michaud, J. P., & Shishehbor, P. (2014). The biology of Lysiphlebus fabarum (Braconidae, Aphidiinae) following cold storage of larvae and pupae. Retrieved from http://krex.ksu.eduCold storage is a one means of preserving parasitoids prior to release in augmentation biological control programs. This study examined the feasibility of storing larval and pupal stages of a sexual population of Lysiphlebus fabarum Marshall (Braconidae: Aphidiinae) at 6.0 and 8.0 °C (± 1.0 °C), 50–60% RH, and 14L:10D photoperiod. These life stages were stored for periods of 1, 2 and 3 weeks under fluctuating thermal regimes (2.0 h daily at 21.0 ± 1.0 °C). Generally, pupae gave better results than larvae, 6.0 °C was better than 8.0 °C, and were better than constant, considering wasp survival, wasp size (tibial and antennal lengths), egg load and egg size. The best results were obtained with pupae stored for two weeks under a fluctuating temperature regime at 6.0 °C. Females emerging from this treatment did not differ from controls (developing directly at 21.0 °C) in body size, egg size, or progeny sex ratio and suffered less than 20% mortality. Egg loads were reduced in these wasps, but the reductions were substantially less than occurred in other two week storage treatments. Wasps stored in this manner successfully parasitized similar numbers of aphids as controls and produced similar progeny sex ratios. These results reveal a suitable set of low temperature conditions that can be used to delay the development of L. fabarum for two weeks with minimal impacts on wasp fitness

Modification of forests by people means only 40% of remaining forests have high ecosystem integrity

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally

Anthropogenic modification of forests means only 40% of remaining forests have high ecosystem integrity

Many global environmental agendas, including halting biodiversity loss, reversing land degradation, and limiting climate change, depend upon retaining forests with high ecological integrity, yet the scale and degree of forest modification remain poorly quantified and mapped. By integrating data on observed and inferred human pressures and an index of lost connectivity, we generate a globally consistent, continuous index of forest condition as determined by the degree of anthropogenic modification. Globally, only 17.4 million km2 of forest (40.5%) has high landscape-level integrity (mostly found in Canada, Russia, the Amazon, Central Africa, and New Guinea) and only 27% of this area is found in nationally designated protected areas. Of the forest inside protected areas, only 56% has high landscape-level integrity. Ambitious policies that prioritize the retention of forest integrity, especially in the most intact areas, are now urgently needed alongside current efforts aimed at halting deforestation and restoring the integrity of forests globally