Our research area consists of the fundamental and applied aspects of the biology of insects with an emphasis on multitrophic interactions.
Our mission is to unravel the ecology of interactions between insects and other community members by combining ecological studies (population and community levels) with investigations of the underlying mechanisms (subcellular to individual levels). Integrated pest, vector and disease management strategies are being developed in both developed and developing countries.
Our objective is to carry out excellent science that is nationally and internationally at the forefront and (inter)nationally well-connected, while working in a group in Wageningen in a stimulating, collaborative atmosphere. The group has an outstanding reputation in multitrophic interactions, biological control, and malaria vector research. There is a strong focus on integrating ecological, physiological and molecular approaches. In our tropical research programme, cooperation with social sciences ensures that societal stakeholders are included in the research process, and that research is centred around the needs and opportunities of farmers. For an optimal dissemination of scientific information to different societal groups, we invest in transferring the knowledge gained to the scientific community, to professional organisations and to the general public.
All our research is embedded in the Graduate Schools Experimental Plant Sciences (EPS) and Production Ecology and Resource Conservation (PE&RC).
In 2012, an international peer review committee evaluated our research as excellent (5 out of 5) for all criteria: Quality, Productivity, Relevance and Viability and thus evaluated us as one of the best research groups in the Netherlands in Biology.
Our research themes are:
We are convinced that understanding the ecology of multitrophic insect-plant interactions at the level of populations and communities necessitates investigating the underlying mechanisms at the level of individual behaviour, plant physiology, animal sensory physiology, plant secondary chemistry, transcriptomics and transcriptional regulation. Our research addresses mechanistic issues in Arabidopsis and Brassica species (exploiting the molecular toolbox), while ecological issues are addressed in cultivated Brassica and natural Brassica populations. Transcriptomic responses of Arabidopsis and Brassica to attackers are studied in conjunction with the effects of individual genes involved in induced plant responses such as induced resistance and induced production of carnivore-attracting volatiles. Through molecular techniques population structures and adaptations of insects to plant chemistry are investigated (population genomics). This research connects plant defence studies with biodiversity studies. Major achievements: (1) functional analysis of plant gene involved in plant ‘bodyguard’ attraction through molecular genetic approach (Science 2005); (2) global transcriptomic analysis of Brassica to caterpillar damage and linking the expression of individual Brassica defence genes to insect community dynamics in the field (BMC Genomics 2007; Mol. Ecol. 2008; Trends Plant Sci. 2008; Ecology 2009); (3) using transgenic approach to show that the terpenoid isoprene, known for its protection of plants to abiotic stress, influences plant defence against biotic stress (PNAS 2008a); (4) molecular ecology of plant response to multiple stresses (PNAS 2009a; Nature Chem. Biol. 2009); (5) identification of the role of butterfly cues in plant-parasitoid interactions (PNAS 2008b, 2009b).
We focus on the attraction of malaria mosquitoes to human odours to contribute to control of the vector of one of the world’s deadliest diseases, i.e. malaria. The programme combines genetic engineering and molecular biology to identify chemical compounds that interact strongly with receptors in the female mosquito’s antennae, and are related to host selection. The programme exploits information on the mosquito’s genome related to genes that encode odorant receptors. The effects of odours in vivo are studied with electrophysiology and behavioural assays. Finally, promising blends of compounds are tested in traps for their effectiveness in affecting mosquito behaviour under semi-field and field conditions in Africa. The application of an odour blend that is more attractive than human odour will be further developed to control malaria in Kenya through a new major grant (3.3 M€ from private funding source). Major achievements: (1) through molecular and physiological approaches plus functional analyses we defined the complete malaria mosquito’s olfactory sensory map (Curr. Biol. 2007); (2) we showed that the African malaria mosquito relies on the combination of ammonia, lactic acid and carboxylic acids in its orientation to human hosts (Chem. Senses 2005); (3) the novel discovery of the effectiveness of an entomopathogenic fungus to control adult malaria mosquitoes in the laboratory and in an African village (Science 2005); (4) the exciting discovery that the microbial community on the human skin determines the attraction of malaria mosquitoes (FEMS Microbiol. Ecol. 2009; Trends Parasitol. 2009).
The UN Millennium Project has called for greater investment in agricultural research for poverty alleviation, especially in Africa. Our participatory research programme, involving close collaboration of natural and social scientists, is based on the principle that innovation is the emergent property of the interaction among different stakeholders in agricultural development. The research addresses the sub-optimal impact of science on the livelihoods of resource-poor farmers in West Africa. We develop insights into the pathways through which investment in science and technology can improve rural lives through participatory experimental and action research. The programme yields concrete results in e.g. integrated pest management in cocoa and cotton (9 PhD students defended their thesis in 2006). Based on the successful first phase, the programme continues with a €4.5 million grant from the Ministry of Foreign Affairs of the Netherlands, focussing on strengthening agricultural innovation systems in Benin, Ghana and Mali (additional 11 PhD students and 9 postdocs involved). Furthermore, participatory approaches are developed for vector-borne disease control in Africa that emphasize the strong interaction between agriculture and health for development. This approach is successfully implemented into different agricultural communities. Major achievements: (1) Experimental content and agricultural research designed for development relevance with farmers and all relevant stakeholders (special double issue Int. J. Agric. Sust. 5(2&3), 2007); (2) At the end of the first phase, for the first time in WU history, the nine PhD students were allowed to defend their theses overseas (Accra and Cotonou, 2006). (3) Main lessons learned were a) Enlarging socio-economic and institutional space allows technological improvements; b) Institutional development results when actors enter into stable relationships and configurations based upon negotiated and agreed rules; c) Investing in experimentation with and capacity building of innovation systems is necessary at the international, national and local levels, involving all stakeholders (Research Policy, 2010).
With the world population rapidly growing towards 9 billion in 2050 there is an urgent need for new sources of animal protein. Insects can provide a sustainable protein source that needs less input and its production yields less waste than the production of conventional meat. We have recently initiated a research programme to investigate the potential of insects as a novel protein source. Feed conversion efficiency, the production of greenhouse gases and the exploitation of different feed sources are investigated in combination with studies on protein extraction and purification. Major achievements: (1) production of insect meat is much more sustainable than the production of conventional meat in terms of the production of greenhouse gases (Plos ONE 2010), (2) the results of the Plos ONE study as well as general information on the project have received ample attention and resulted in an invitation to write a paper in the Wall Street Journal (19 feb 2011), (3) publication of Het Insectenkookboek, a cookbook with ample background information, that will be published in an English version in 2013.
Our researchers are: