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Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2007

Sammendrag

The large arionid slug Arion lusitanicus is a serious pest in northern Europe including many parts of Norway. In Norway it is mainly a pest in home gardens but in recent years it has also spread to horticultural and vegetable crops such as strawberry and lettuce. The use of the slug parasitic nematode Phasmarhabditis hermaphrodita against A. lusitanicus is being investigated in an ongoing research project that was initiated in 2005. A survey was conducted to examine the natural occurrence of the slug parasitic nematode P. hermaphrodita. The result of the survey was positive which led to registration of the product Nemaslug in 2005. Several experiments have been conducted to study the effect of both the commercial product Nemaslug and Norwegian isolated P. hermaphrodita on A. lusitanicus slugs. Laboratory and controlled pot experiments confirm that young stages of the slug (0.02 - 0.04g) are most susceptible to infection and death. It also appears that soil based bioassays give more consistent results than assays using Petri dishes with filter paper. Further work on the infection process of nematodes in A. lusitanicus slugs as well as the practical aspects of nematode use in gardens and the field are being addressed.

Sammendrag

De fleste av oss har, enten vi har hage, dyrket mark eller ferdes i skog og mark, hatt befatning med iberiaskogsneglen, brunsneglen, mordersneglen, rambosneglen. Mange navn på en etter hvert velkjent skapning i hagene våre. Sneglene tar godt for seg av plantene blomsterbedet, og man kvier seg for å gå barbeint over en duggfrisk villaplen en sen sommerkveld. Salat- og jordbærbøndene har ennå mer å frykte, eller? Foredrag om iberiaskogsnegl levesett og bekjempelse.

Sammendrag

Occurrence of entomopathogenic nematodes (EPNs) have been reported from all continents in the world except Antarctica. Africa is the continent with fewest reports so far. There have however been reports on EPNs occurrence in Egypt, Kenya and South Africa. EPNs are well known due to their potential as biological control agents of insect pests. Banana weevil (Cosmopolites sordidus) is as an important insect pest of banana. This pest causes reduced banana production in all countries of the East African Highlands in particular Tanzania and Uganda. Different strategies have been employed to control the insect. However the potential for using entomopathogenic nematodes as biological control agents of the weevil has not yet been considered in Tanzania. A preliminary study is ongoing to find out if entomopathogenic nematodes naturally exist in banana growing areas in Tanzania. Currently nine soil samples have been collected from three regions (Mbeya, Morogoro and Coast) with different agroecological conditions. The samples have been taken to Bioforsk in Norway, for extraction of EPNs. Analysis of the samples has been done using larvae of the Greater Wax moth (Galleria mellonella) as bait. After 7 and 14 days dead larvae were removed from the soil samples and placed on water agar. Some of the dead larvae were infected with entomopathogenic fungi and at least one sample had a dead larva with EPN infection. In this sample an adult nematode in the genus Steinernema was isolated. Many dead larvae also had what appeared to be secondary infections of saprophytic nematodes (Rhabditidae) and/or saprophytic fungi. Identification to species or genus level of the nematodes is ongoing. This study reports the find of EPNs for the first time in Tanzania. The isolation of indigenous EPNs are important for further studies on their suitability for control of local insect pests including banana weevils. Future work will include more soil samples for EPNs analysis and semi-field tests using EPNs against banana weevil.

Sammendrag

Occurrence of entomopathogenic nematodes (Epn) have been reported from all continents in the world except Antarctica. Africa is the continent with fewest reports so far. There have however been reports on Epn occurrence in Egypt, Kenya and South Africa. Epns are well known due to their potential as biological control agents of insect pests. Banana weevil (Cosmopolites sordidus) is considered as an important insect pest of banana. This pest causes reduced banana production in all countries of the East African Highlands in particular Tanzania and Uganda. Different strategies have been employed to control the insect. However the potential for using entomopathogenic nematodes as biological control agents of the weevil has not yet been considered in Tanzania. A preliminary study is ongoing to find out if entomopathogenic nematodes naturally exist in banana growing areas in Tanzania. Currently nine soil samples have been collected from three regions (Mbeya, Morogoro and Coast) with different ecological conditions. The samples have been taken to Bioforsk in Norway, for extraction of Epn. Analysis of the samples has been done using larvae of the Greater Wax moth (Galleria mellonella) as bait. After 7 and 14 days dead larvae were removed from the soil samples and placed on water agar. Some of the dead larvae were infected with entomopathogenic fungi and at least one sample had a dead larva with Epn infection. In this sample an adult nematode in the genus Steinernema was isolated. Many dead larvae also had what appeared to be secondary infections of saprophytic nematodes (Rhabditidae) and/or saprophytic fungi. Identification to species or genus level of the nematodes is ongoing. This study reports the find of Epn for the first time in Tanzania. The isolation of indigenous Epns are important for further studies on their suitability for control of local insect pests including banana weevils. Future work will include more soil samples for Epn analysis and semi-field tests using Epn against banana weevil.

Sammendrag

Fra tid til annen gulner plenen og andre grøntarealer uten at noen synlig grunn foreligger. Årsaken til gulningen kan være oldenborrelarver. Artikkelen beskriver problemet med oldenborrer i plen og om bekjempelse.

Sammendrag

Entomopathogenic nematodes (EPNs) are commercially available for control of soil dwelling larvae of the vine weevil (Otiorhynchus sulcatus). In Europe several products are available comprising three different species, Heterorhabditis bacteriophora, H. megidis, and Steinernema kraussei. The latter species is for use at low temperatures. Results from several trials using H. megidis and S. kraussei against vine weevil in strawberry fields indicate that low temperature, soil type and possibly the application method are limiting factors that appear to reduce their efficacy. The use of EPNs against vine weevil larvae in the field will be discussed including results from cold-activity studies and application methods.

Sammendrag

Different methods to reduce the population of Arion lusitanicus are being investigated in private gardens naturally infested with the slug. In the laboratory the effect of different mulches are also being tested. Preliminary results from the studies conducted in gardens indicate that physical removal of slugs by picking or trapping and killing is most effective. In arenas in the laboratory, slugs avoided cocoa chips mulch and alginate granules. These studies are on-going and will be completed at the end of 2008. The slug parasitic nematode Phasmarhabditis hermaphrodita has recently been isolated in Norway. It is being studied as a biological control agent of A. lusitanicus. Results so far show that young slugs (0,02 " 0,04g) are most susceptible to infection and death. It also appeared that soil based bioassays gave better and more consistent results than assays using Petri dishes with filter paper. Further studies on the host-parasitic relationship of the nematode and slug are required.

Sammendrag

The large arionid slug Arion lusitanicus is a serious pest in parts of northern Europe including many parts of Norway. In Norway it has mainly been a pest in home gardens but in recent years it has also spread to horticultural and vegetable crops such as strawberry and lettuce. The use of the nematode Phasmarhabditis hermaphrodita against A. lusitanicus is being investigated in an on-going research project that was initiated in 2005. A survey was conducted in 2004 to examine if the nematode P. hermaphrodita could be found occurring naturally in Norway. The result of the survey was positive which led to registration of the product Nemaslug in 2005. Several experiments have been carried out since 2005, to study the effect of both the commercial product Nemaslug and Norwegian isolated P. hermaphrodita on A. lusitanicus slugs. Laboratory and controlled pot experiments confirm that young stages of the slugs are susceptible to the slug parasitic nematode. Further work on the infection process of nematodes in slugs as well as the practical aspects of nematode use in gardens and the field will be addressed as a next step in these studies.