Avancerad sökning
Hittade 4 uppsatser som matchar ovanstående sökkriterier.
1. Skadeinsekters populationsdynamik i ett heterogent jordbrukslandskap
Kandidat-uppsats, Lunds universitet/Examensarbeten i biologiSammanfattning : Chemical pesticides have long been used to keep crops free from pests, but in modern agriculture biological control is viewed as a viable alternative to pesticides. The concept of biological control is to implement predators that feed upon the pests. LÄS MER
2. Biological control of thrips with Neoseiulus cucumeris and Orius majusculus in strawberry tunnels
Master-uppsats, SLU/Dept. of Plant Breeding (from 130101)Sammanfattning : Several cases of thrips resistance to pesticides have been observed due to heavy usage of insecticides during the seventies-eighties. Thrips complex enzyme metabolic detoxification system and fast reproduction has lead to a classification of major pest in strawberry production. LÄS MER
3. An ecological study of the migration, food composition and relative abundance of three-spined stickleback (Gasterosteus aculeatus) in a shallow area in Kalmar Sound.
Kandidat-uppsats, Linnéuniversitetet/Institutionen för biologi och miljö (BOM)Sammanfattning : The populations of three–spined sticklebacks (Gasterosteus aculeatus) in the Baltic Sea have increased tenfold over the last decade. A large increase in abundance can alter the offshore and coastal food webs. LÄS MER
4. Kan fiskpredation reglera populationer av storspigg (Gasterosteus aculeatus) i Östersjön?
Kandidat-uppsats, Institutionen för naturvetenskap, NVSammanfattning : Fiskbestånden i Östersjön har sedan början av 1980-talet genomgått en omfattande förändring. Stora predatorer, som torsk (Gadus morhua) och abborre (Perca fluviatilis) har minskat i antal medan det finns tecken på att storspigg (Gasterosteus aculeatus) har ökat. LÄS MER