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Postdoc position in ecology

A Postdoctoral researcher position is available with Dr Arne Janssen, Department of Evolutionary and Population Biology within the Institute for …

2 maanden geleden


Science Park, Amsterdam, Noord-Holland
Vast contract
Uren per week:
38 - 38 uur
€ 2709 - € 4274 per maand


A Postdoctoral researcher position is available with Dr Arne Janssen, Department of Evolutionary and Population Biology within the Institute for Biodiversity and Ecosystem Dynamics (IBED) at the University of Amsterdam.

This postdoctoral position is part of the research projects 'Tropical predators from coconut to save Dutch tulip bulbs', and 'Biological control of the emerging pest Echinothrips americanus and other new thrips pests in ornamental crops', both financed by the NWO domain Applied and Engineering.

Project description

Pesticides have negative environmental side effects, and there is increasing demand for alternative, environmental friendly pest control methods such as biological control. The current projects focus on two pest groups in ornamentals. One of the most damaging pests in the storage of tulip bulbs is the small dry bulb mite, which hides between bulb scales where it is inaccessible for its much larger predators. Thus far, control of this pest is therefore based on the use of chemicals. We recently showed that an extremely flat predatory mite from coconut trees is promising for the control of this pest because it can enter the space between the scales, but this predator is difficult to rear. We aim to develop an environmental-friendly biological control method with another flat generalist predator from coconuts and other candidate mites, which are easier to cultivate. Other pests in ornamentals are the thrips species Echinothrips americanus and potential new thrips pests Scirtothrips dorsalis and Thrips setosus. Although several predatory mites can feed on young stages of Echinothrips and controlled the pest on small groups of crop plants in cages, biological control with these predators in greenhouses have failed. We aim to test a new species predatory mite inhabiting the soil to control these thrips in roses and other ornamentals. The idea is to use a practice that has gained popularity among biocontrol companies and growers, which is to supply the predators with alternative food. The main advantage of this is that it allows establishment of populations of natural enemies without pests by supplying them with alternative, non-pest food. Thus, pests that invade the crop find them protected by a standing army of their enemies, and when pests are already present in part of the crop, the predators can prevent their spread by protecting uninfested plants or bulbs. Although the method of supplying alternative food has been proven successful and is gaining popularity among growers, there is hardly any research on the amount and quality of the alternative food as well as the frequency of supply. This is not a trivial matter because feeding too infrequently or too much may result in deflecting the attacks of the predators from the pest to the alternative food.
Theoretical literature exists on the effects of such resource pulses (the alternative food in this case) on dynamics of single populations, but not much on the dynamics of coupled predator-pest systems.

What are you going to do?

Within the framework of this project, we are looking for a Postdoc (during 4 years), experienced with constructing detail-rich population models of predators and prey and with proven experimental experience with small arthropods. The tasks will consist of further developing continuous-time mathematical population models based on models developed in our department, and parametrizing and testing them through experiments. The goal is to assess optimal frequencies and quantities of food supply to maintain predator populations and control the pests. The research will be carried out in collaboration with a half-time postdoc who already works on control of the dry bulb mite and a PhD student to be contracted for the experimental work on thrips control.


  • A PhD in ecology, evolution or related field;
  • good modelling skills, especially in continuous-time predator-prey models of the Lotka-Volterra type;
  • experience with experimental work on small arthropods;
  • excellent written, oral communication and collaboration skills;
  • fluency in English, both written and spoken.


A temporary contract for 38 hours per week, for the duration of 48 months. Preferred start date June 2020. Initial appointment will be for a period of 18 months and after satisfactory evaluation it will be extended for a total duration of 4 years.

The salary, depending on relevant experience before the beginning of the employment contract, will be €2,709 to €4,274 (scale 10) gross per month, based on full-time employment (38 hours a week). These amounts are exclusive 8 % holiday allowance and 8,3 % end-of-year bonus. A favorable tax agreement, the ‘30% ruling’, may apply to non-Dutch applicants. The Collective Labour Agreement of Dutch Universities is applicable.

Are you curious about our extensive package of secondary employment benefits like our excellent opportunities for study and development? Then find out more about working at the Faculty of Science.

Additional information

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