Sökning: "aphids"

Visar resultat 11 - 15 av 16 avhandlingar innehållade ordet aphids.

1. 11. Get a grip on chaos : Tailored measures for complex systems on surfaces

   Författare :Sascha Firle; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; complex systems; chaos; predator prey; movement models; functional response; spatial heterogeneity; topological dynamics; braid template; homoclinic bifurcations; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

   Sammanfattning : Complex systems are ubiquitous in physics, biology and mathematics. This thesis is concerned with describing and understanding complex systems. Some new concepts about how large systems can be viewed in a lower dimensional framework are proposed. The systems presented are examples from ecology and chemistry. LÄS MER

3. 12. Insect-plant interactions within cultivar mixtures : volatile plant communication as an underlying mechanism

   Författare :Sokha Kheam; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Promoting genotypic diversity of crops via cultivar mixtures presents a promising strategy to sustainably control insect pests and diseases, and thereby enhance yield. However, the underlying mechanisms responsible for reduced pest performance in cultivar mixtures remain unexplored. LÄS MER

4. 13. Chemical defence in Norway spruce

   Författare :Marie Danielsson; Anna-Karin Borg-Karlson; Anders Backlund; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volatiles; terpenes; green leaf volatiles; stilbenes; stress response; nepetalactone; Picea abies; Hylobius abietis; Cinara pilicornis; Oligonychus ununguis; Heterobasidion annosum; Chemistry; Kemi;

   Sammanfattning : Norway spruce (Picea abies) responds to stress by biosynthesis of chemical substances, which can deter invading insects or pathogens. Some of these substances are volatile and can be emitted to the surroundings while others are accumulated within the tree. LÄS MER

5. 14. Interactions between ants and pine weevils : effects on forest regeneration

   Författare :Vita Manak; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Ants interact with plants in various ways and ant presence on plants can decrease local abundance or activity of herbivores, which in turn increases plant fitness. Red wood ants (Formica rufa group) are common species in forests of northern Europe. LÄS MER

7. 15. Attract, reward and disrupt: combining habitat manipulation and semiochemicals to enhance pest control in apple orchards

   Författare :Joakim Pålsson; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Agricultural intensification entails negative effects on natural enemy populations and the pest regulation services they provide. Habitat manipulation holds potential to control pests with less negative effects on the environment than conventional methods. LÄS MER