Karin Westrum
Senioringeniør
Sammendrag
I 2022 ble det utført forsøk med skadedyrmidler i frukt og bær, og anlagt et forsøk i hodekål. I eple er det utført forsøk med ulike kjemiske og biologiske plantevernmidler mot blodlus (Eriosoma lanigerum), rognebærmøll (Argyresthia conjugella) og andre sommerfuglarter. I søtkirsebær er det utført et forsøk med feller med gjærlukt kombinert med farge for å øke fangsten og eventuelt også bekjempelse av kirsebærflue (Rhagoletis cerasi). Det er også utført forsøk med alternative midler mot bringebærbarkgallmygg (Resseliella theobaldi) i økologisk bringebær. Forsøket mot kålmøll i hodekål ble anlagt og delvis registrert, men ikke fullført på grunn av svakt angrep. Forsøkene og enkelte forsøksledd er finansiert av ulike prosjekter og finansieringskilder.
Sammendrag
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.
Forfattere
Stephanie Saussure Annette Bruun Jensen Marie Louise Davey Annette Folkedal Schjøll Karin Westrum Ingeborg KlingenSammendrag
In Scandinavia, the bird cherry-oat aphid Rhopalosiphum padi overwinter as eggs on the bird cherry tree Prunus padus. Branches of P. padus were collected at the late February / early March from 17 locations in Norway over a three-year period. We found 3599 overwintering aphid eggs, 59.5% of which were dead. Further, a total of 879 overwintering fungus-killed cadavers were observed. These cadavers were found close to bud axils, where overwintering eggs were also usually attached. Cadavers were infected with either Zoophthora cf. aphidis or Entomophthora planchoniana. All the fungal-killed cadavers were filled with overwintering structures of Z. cf. aphidis (as resting spores) or E. planchoniana (as modified hyphal bodies). We found a significant negative correlation between eggs and cadavers per branch. However, both numbers of eggs and cadavers varied greatly between years and among tree locations. This is the first report of E. planchoniana overwintering in R. padi cadavers as modified hyphal bodies. We discuss whether P. padus may act as an inoculum reservoir for fungi infecting aphids in cereals in spring.