Essays about: "insect populations"

Showing result 21 - 24 of 24 essays containing the words insect populations.

  1. 21. Insektspatogena svampar för biologisk bekämpning av bladlöss i stråsäd : möjligheter och hinder

    University essay from SLU/Dept. of Ecology

    Author : Jonas Törngren; [2013]
    Keywords : insektspatogena svampar; Entomophthorales; bevarande; biologisk bekämpning; bladlöss; stråsäd;

    Abstract : Att insektspatogena svampar har potential som biologisk bekämpning av bladlöss råder det ingen tvekan om. Försök runt om i världen visar på att svamparna, under rätt omständigheter, kan utveckla epizootier och slå ut stora delar av bladlössens populationer. READ MORE

  3. 22. Stay below water! - a strategy to avoid seed predators : - seed survival and germination of Mauritia flexuosa in southeastern Peru

    University essay from Ekologi

    Author : Björn Johansson; [2009]
    Keywords : Aguaje; Amazon; germination; insects; Mauritia flexuosa; palm; Peru; seed predation;

    Abstract : The tropical palm Mauritia flexuosa has highly nutritious fruits and is an important food resource for both humans and wildlife throughout its geographic range in South America. Unsustainable harvesting threatens wild populations. Mauritia f. occurs primarily in wetlands called Aguajales where it can become the dominating canopy species. READ MORE

  4. 23. Correlation between photoperiod and development rate in the damselfly Lestes sponsa (Hansemann) : A compensating mechanism across latitudes?

    University essay from Institutionen för ekologi, miljö och geovetenskap

    Author : Szymon Sniegula; [2009]
    Keywords : development insects aquatic ecology;

    Abstract : Although there is much theoretical and empirical data about the life history responses of time constrained organisms, little is known about the latitude compensating mechanism that enables northern populations’ developmental rates to compensate for latitude. To investigate the importance of photoperiod on development and growth, I collected adults and raised the offspring of the obligatory univoltine damselfly Lestes sponsa from two populations at different latitudes (53º N and 63º N). READ MORE

  5. 24. Field margins vs. insecticides : factors affecting the density of predators attacking Plutella xylostella

    University essay from SLU/Dept. of Ecology

    Author : Lina Grönberg; [2007]
    Keywords : predators; Plutella xylostella; diamondback moth; field margins; biological control; Nicaragua;

    Abstract : Biological control provides a tool to reach goals such as maintaining sustainable agroecosystems and decreasing the use of pesticides. Studies show that generalist predators can reduce prey populations effectively and, thus, may function as good biocontrol agents. READ MORE