Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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Performance of the Black Soldier Fly (Diptera : Stratiomyidae) on Vegetable Residue-Based Diets Formulated Based on Protein and Carbohydrate Contents
Barragán-Fonseca, Karol ; Pineda-Mejia, Julián ; Dicke, Marcel ; Loon, Joop J.A. van - \ 2018
Journal of Economic Entomology 111 (2018)6. - ISSN 0022-0493 - p. 2676 - 2683.

The black soldier fly [Hermetia illucens L. (Diptera: Stratiomyidae)] can be sustainably reared on organic waste streams and thereby provide a novel animal protein source for animal feed. Black soldier fly's performance and body composition depend to a large extent on the nutrient composition of the waste stream. Black soldier fly larvae were fed on four diets consisting of vegetable by-products from the food industry. All four diets contained dried distiller's grains with solubles plus one or two other main ingredients; for diet 1 the additional ingredient was grape pulp; diet 2: potato peels; diet 3: bean seeds; and diet 4: cabbage leaves plus old bread. The diets were formulated based on an optimal summed protein and carbohydrate (P+C) concentration resulting from previous experiments and a 1:2 protein:carbohydrate (P:C) ratio. We quantified both larval and adult performance. Diet 4 was the best performing vegetable waste-based diet. In a follow-up experiment, we re-formulated diet 4 to have P:C ratios of 1:2 or 1:3 and 40 or 47% dry matter of P+C. In the first experiment, although there were differences in larval performance among the diets, all diets supported a higher larval performance than reported previously, with diet 4 having 47% P+C being the best performing diet. We infer that not only total macronutrient content but also nutritional quality of proteins and carbohydrates affected performance. In the second experiment, the two vegetable residue-based larval diets resulted in similar larval and adult performance. High dietary protein resulted in increases in larval crude fat content.

The potential of future foods for sustainable and healthy diets
Parodi, A. ; Leip, A. ; Boer, I.J.M. De; Slegers, P.M. ; Ziegler, F. ; Temme, E.H.M. ; Herrero, M. ; Tuomisto, H. ; Valin, H. ; Middelaar, C.E. Van; Loon, J.J.A. Van; Zanten, H.H.E. Van - \ 2018
Nature Sustainability 1 (2018). - ISSN 2398-9629 - p. 782 - 789.
Altering diets is increasingly acknowledged as an important solution to feed the world’s growing population within the planetary boundaries. In our search for a planet-friendly diet, the main focus has been on eating more plant-source foods, and eating no or less animal-source foods, while the potential of future foods, such as insects, seaweed or cultured meat has been underexplored. Here we show that compared to current animal-source foods, future foods have major environmental benefits while safeguarding the intake of essential micronutrients. The complete array of essential nutrients in the mixture of future foods makes them good-quality alternatives for current animal-source foods compared to plant-source foods. Moreover, future foods are land-efficient alternatives for animal-source foods, and if produced with renewable energy, they also offer greenhouse gas benefits. Further research on nutrient bioavailability and digestibility, food safety, production costs and consumer acceptance will determine their role as main food sources in future diets.
Disentangling agronomic and economic yield gaps in Ethiopian wheat based systems for better targeting of development interventions (Yield Gap Wheat Ethiopia) : Report #2: Data availability, description and quality
Silva, J.V. ; Morley, Tomas ; Loon, M.P. van; Reidsma, P. ; Ittersum, M.K. van - \ 2018
- 24 p.
Developing a running prototype of a bio-economic farm model for a trade-off analysis of different nutrient management options for maize cultivation in East-Africa
Hijbeek, R. ; Berge, H.F.M. ten; Loon, M.P. van; Ittersum, M.K. van - \ 2018
CGIAR (Working paper. Wageningen, the Netherlands: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) ) - 25 p.
Considering projected population trends, food requirements in East Africa will drastically increase in the coming decades (van Ittersum et al., 2016). One way to ensure supply will meet demand is by raising crop yields in the region. In East Africa, agricultural yields still have large potential to increase due to the large gaps between actual and potential yields. A recent study has shown that intensification of agriculture in regions with low current yields (such as in East Africa) is an option to reduce greenhouse gas emissions by avoiding or reducing agricultural land expansion into forests and/or grasslands, thus preserving carbon stocks (Van Loon, Hijbeek, ten Berge and Van Ittersum 2018, in prep). This is however only valid if higher yields are obtained with highly efficient use of fertilisers. For a successful implementation of such climate smart agricultural intensification, improved nutrient management options need to be economically viable for farmers in East Africa. It is however often unclear under which conditions agricultural intensification is beneficial for farmers’ income in sub saharan Africa (Marenya and Barrett, 2009; Place et al., 2003; Sheahan et al., 2013). Besides a number of good agricultural practices (such as improving planting densities and sound crop protection measures), farmers need to apply more nutrients to intensify production. The amounts of additional nutrients required represents the ‘nutrient gap’ between current nutrient applications and the total amount of nutrients removed from fields with increased yields (de Vries et al., 2017). Farmers can use several nutrient management options to close the nutrient gap (e.g. use mineral or organic fertilisers, split application of fertilisers, combine with local or hybrid seeds). The nutrient management option a farmer chooses not only affects his or her nutrient use efficiency (how much of the applied nutrients are recovered by the crop), but also his or her income generation and the contribution to greenhouse gas emissions. Some practices might be most beneficial for farmers’ income, but have a larger contribution to greenhouse gas emissions. Others might have the reversed effect. So far, trade-offs and/or synergies between farmers’ income and greenhouse gas mitigation as a function of nutrient management options have not been systematically assessed. Additionally, it is uncertain how such trade-offs or synergies might evolve over time, in cases where soil carbon and nutrient pools respond over longer time frames to the management exposed. We therefore address the following question: Can certain nutrient management practices be identified which are beneficial for both climate change mitigation and for farmers’ income in East Africa? The aim of this report is to develop a running prototype of a bio-economic model which can be used to assess trade-offs between yields, farmers ‘income and greenhouse gas emissions in function of different nutrient management options, both on the short and the long term. The proposed model will focus on nitrogen (N) as the main limiting nutrient, which is also highly relevant for greenhouse gas emissions (i.e. N2O). The model will be useful for R&D investors, agri-business (including fertiliser companies) and government agencies for ex ante assessment of specific nutrient management options.
A framework to parameterise nutrient management options and their impacts on maize yield, nutrient losses and long term soil fertility
Berge, H.F.M. ten; Hijbeek, R. ; Hermelink, Marleen ; Loon, M.P. van; Ittersum, M.K. van - \ 2018
CGIAR (Working paper. Wageningen, the Netherlands: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) ) - 47 p.
Climate Smart Agriculture (CSA) encompasses all practices that mitigate climate change and at the same time enhance farmers’ livelihoods and adaptation to changing climate. Nutrient management is an important tool for farmers to increase yields. Efficient use of nutrients is necessary to limit greenhouse gas (GHG) emissions and costs of external inputs. To enable an overall assessment of the opportunities that nutrient management presents for CSA, nutrient cycles and dynamics need to be thoroughly understood. This report describes a framework to parametrise the impacts of nutrient inputs on the nutrient balance, crop yield and soil fertility, both in the short and the long term. Separating short term versus long term processes and internal crop processes versus crop-soil interactions results in four sets of equations that are mutually consistent. These can be viewed as alternative approaches to quantify nutrient requirements and associated impacts, depending on purpose of a study. Set 1 expresses nutrient uptake requirement as a function of target yield, both in short and long term. Set 2 expresses input requirements as function of target uptake, soil nutrient supply and fertiliser recovery in the short term. Set 3 is similar in structure and purpose to Set 2, but includes a long term feedback of nutrient input on fertiliser recovery via soil fertility. Set 4 is a reduction of Set 3, under a specific boundary condition imposing ‘efficient management’ in a simplified manner. The full sequence of relating a target yield to input requirement (or vice versa) is expressed by combinations of these sets: Sets 1 and 2 (short term), Sets 1 and 3 (long term equilibrium, generic), and Sets 1 and 4 (long term equilibrium, efficient management). The processes expressed by the sets of equations are governed by parameters that depend on management options (e.g. 4Rs: right source, rate, timing, placement), and have a direct bearing on overall nutrient use efficiency as expressed in agronomic N use efficiency (ANE, kg extra grain yield per kg N input), and associated impacts. The framework presented in this report is applied in other components of the Crop Nutrient Gap Project (Bringing CSA practices to scale), notably in (i) presenting spatial maps of nutrient requirements for different levels of yield gap closure in sub-Saharan Africa (www.yieldgap.org), (ii) assessing GHG emissions for contrasting intensification scenarios; and (iii) assessing trade-offs between food security, farm income and climate change mitigation.
Effects of waste stream combinations from brewing industry on performance of black soldier fly, Hermetia illucens (Diptera: Stratiomyidae)
Chia, Shaphan Y. ; Tanga, Chrysantus M. ; Osuga, Isaac M. ; Mohamed, Samira A. ; Khamis, Fathiya M. ; Salifu, Daisy ; Sevgan, Subramanian ; Fiaboe, Komi K.M. ; Niassy, Saliou ; Loon, Joop J.A. van; Dicke, Marcel ; Ekesi, Sunday - \ 2018
PeerJ 2018 (2018)11. - ISSN 2167-8359
Agro-industrial by-products - Hermetia illucens - Mass rearing - Net energy - Protein quality - Quality control parameters

Background: In recent years, there has been a rapidly growing demand for readily accessible substrates for mass production of Black Soldier Fly, Hermetia illucens Linnaeus. Beer production results in various by-products that typically end up in uncontrolled dumpsites constituting pollution problems, which merits urgent attention. The present study investigated whether the 12 formulated diets composed of brewers’ spent grains (BSGs), brewers’ yeast and cane molasses can serve as substrate for H. illucens production. Methods: Four different BSGs were selected and formulated into 12 diets, aiming at varying protein and net energy levels. The diets were offered to newly hatched (∼1 h old) H. illucens larvae and the influence on developmental duration, survival, wet weight, pre-oviposition time, fecundity, and longevity were compared. Results: Developmental duration of the larvae (16–21 days) and pre-pupae (8–11 days) differed significantly across the different diets. The developmental duration of the pupae (8.7–9.1 days) was not affected by diet. The larval (86–99.2%), pre-pupal (71–95%), and pupal (65–91%) survival rates varied significantly between flies reared on the different diets. The pre-oviposition time was similar for flies provided with water (7–11 days) and 10% sugar solution (8–14 days) or across the different diets. The mean fecundity per female ranged from 324–787 eggs and did not differ between females provided with water or sugar solution. However, the number of eggs laid per female varied significantly across the different diets when provided with water. The longevity of starved H. illucens adults was significantly lower (5 days) compared to those provided with water (11–14 days) or sugar solution (14–15 days). Discussion: The implications of these findings as part of a quality control procedure for commercial production of high-quality H. illucens larvae as an alternative protein ingredient in livestock and aquaculture feed are discussed.

Greenhouse Gas Emissions Associated to Different Agricultural Intensification Scenarios of Maize Production in Sub-Saharan Africa
Loon, Marloes van - \ 2018
Water shortages worsened by reservoir effects
Baldassarre, Giuliano Di; Wanders, Niko ; AghaKouchak, Amir ; Kuil, Linda ; Rangecroft, Sally ; Veldkamp, Ted I.E. ; Garcia, Margaret ; Oel, Pieter R. van; Breinl, Korbinian ; Loon, Anne F. van - \ 2018
Nature Sustainability 1 (2018)11. - ISSN 2398-9629 - p. 617 - 622.

The expansion of reservoirs to cope with droughts and water shortages is hotly debated in many places around the world. We argue that there are two counterintuitive dynamics that should be considered in this debate: supply–demand cycles and reservoir effects. Supply–demand cycles describe instances where increasing water supply enables higher water demand, which can quickly offset the initial benefits of reservoirs. Reservoir effects refer to cases where over-reliance on reservoirs increases vulnerability, and therefore increases the potential damage caused by droughts. Here we illustrate these counterintuitive dynamics with global and local examples, and discuss policy and research implications.

Threshold temperatures and thermal requirements of black soldier fly Hermetia illucens : Implications for mass production
Chia, Shaphan Yong ; Tanga, Chrysantus Mbi ; Khamis, Fathiya M. ; Mohamed, Samira A. ; Salifu, Daisy ; Sevgan, Subramanian ; Fiaboe, Komi K.M. ; Niassy, Saliou ; Loon, Joop J.A. van; Dicke, Marcel ; Ekesi, Sunday - \ 2018
PLoS One 13 (2018)11. - ISSN 1932-6203

Efforts to recycle organic wastes using black soldier fly (BSF) Hermetia illucens into high-nutrient biomass that constitutes a sustainable fat (biodiesel) and high-quality protein ingredient in animal feeds have recently gained momentum worldwide. However, there is little information on the most suitable rearing conditions for growth, development and survivorship of these flies, which is a prerequisite for mass production technologies. We evaluated the physiological requirements for growth and reproduction of H. illucens on two diets [spent grains supplemented with brewers' yeast (D1) and un-supplemented (D2)]. Development rates at nine constant temperatures (10-42°C) were fitted to temperature-dependent linear and non-linear day-degree models. Thereafter, life history table parameters were determined within a range of favourable temperatures. The thermal maximum (TM) estimates for larval, pre-pupal and pupal development using non-linear model ranged between 37.2 ± 0.3 and 44.0 ± 2.3°C. The non-linear and linear day-degree model estimations of lower developmental temperature threshold for larvae were 11.7 ± 0.9 and 12.3 ± 1.4°C for D1, and 10.4 ± 1.7 and 11.7 ± 3.0°C for D2, respectively. The estimated thermal constant of immature life stages development of BSF was higher for the larval stage (250±25 DD for D1 and 333±51 for D2) than the other stages evaluated. Final larval wet weight was higher on D1 compared to D2. The population growth rate was most favourable at 30-degree celsius (°C) with higher intrinsic rate of natural increase (rm = 0.127 for D1 and 0.122 for D2) and shorter doubling time (5.5 days for D1 and 5.7 days for D2) compared to the other temperatures. These results are valuable for the optimization of commercial mass rearing procedures of BSF under various environmental conditions and prediction of population dynamics patterns using computer simulation models.

A European Multi Lake Survey dataset of environmental variables, phytoplankton pigments and cyanotoxins
Mantzouki, E. ; Campbell, J. ; Loon, E. van; Visser, P. ; Konstantinou, I. ; Antoniou, M. ; Giuliani, G. ; Machado-Vieira, D. ; Gurjão de Oliveira, A. ; Maronić, D.Š. ; Stević, F. ; Pfeiffer, T.Ž. ; Vucelić, I.B. ; Žutinić, P. ; Udovič, M.G. ; Plenković-Moraj, A. ; Tsiarta, N. ; Bláha, L. ; Geriš, R. ; Fránková, M. ; Christoffersen, K.S. ; Warming, T.P. ; Feldmann, T. ; Laas, A. ; Panksep, K. ; Tuvikene, L. ; Kangro, K. ; Häggqvist, K. ; Salmi, P. ; Arvola, L. ; Fastner, J. ; Straile, D. ; Rothhaupt, K.O. ; Fonvielle, J. ; Grossart, H.P. ; Avagianos, C. ; Kaloudis, T. ; Triantis, T. ; Zervou, S.K. ; Hiskia, A. ; Gkelis, S. ; Panou, M. ; McCarthy, V. ; Senerpont Domis, L.N. de; Seelen, L. ; Verstijnen, Y. ; Lürling, M. ; Maliaka, V. ; Faassen, E.J. - \ 2018
Scientific Data 5 (2018). - ISSN 2052-4463 - 13 p.
Under ongoing climate change and increasing anthropogenic activity, which continuously challenge ecosystem resilience, an in-depth understanding of ecological processes is urgently needed. Lakes, as providers of numerous ecosystem services, face multiple stressors that threaten their functioning. Harmful cyanobacterial blooms are a persistent problem resulting from nutrient pollution and climate-change induced stressors, like poor transparency, increased water temperature and enhanced stratification. Consistency in data collection and analysis methods is necessary to achieve fully comparable datasets and for statistical validity, avoiding issues linked to disparate data sources. The European Multi Lake Survey (EMLS) in summer 2015 was an initiative among scientists from 27 countries to collect and analyse lake physical, chemical and biological variables in a fully standardized manner. This database includes in-situ lake variables along with nutrient, pigment and cyanotoxin data of 369 lakes in Europe, which were centrally analysed in dedicated laboratories. Publishing the EMLS methods and dataset might inspire similar initiatives to study across large geographic areas that will contribute to better understanding lake responses in a changing environment.
The effect of plant development on thrips resistance in Capsicum
Haperen, Pauline van; Voorrips, Roeland E. ; Loon, Joop J.A. van; Vosman, Ben - \ 2018
Arthropod-Plant Interactions (2018). - ISSN 1872-8855 - 8 p.
Frankliniella occidentalis - Host plant resistance - Leaf age - Plant age

Western flower thrips [Frankliniella occidentalis (Pergande)] is a worldwide pest insect that causes damage in pepper cultivation, so growers would benefit from host plant resistance. The objectives of this study were (1) to evaluate the effect of plant age on thrips resistance using nine Capsicum accessions with different levels of thrips resistance at three different plant ages, and (2) to study the effect of leaf age on thrips resistance in a resistant and a susceptible pepper accession. The fraction of first instar larvae that did not develop into second instar was used as a measure for thrips resistance. Our results show that plants start to develop thrips resistance when they are between 4 and 8 weeks old. This transition was most marked on the resistant accession CGN16975, on which about 50% of the L1 larvae developed into the next stage on 4-week-old plants, whereas none of them developed beyond the L1 stage on 8- or 12-week-old plants. Furthermore, it is shown that youngest fully opened leaves of the resistant accession CGN16975 are significantly more resistant to thrips than older leaves; 89% of the L1 larvae did not develop into the next stage on the youngest leaves, whereas 57% did not develop beyond the L1 stage on the oldest leaves. Young leaves of the susceptible accession CGN17219 are more susceptible than older leaves; 9 versus 52% of the L1 larvae did not develop into the next stage on young and old leaves, respectively. These findings can be used to improve integrated pest management strategies.

Cereal yield gaps across Europe
Schils, René ; Olesen, Jørgen E. ; Kersebaum, Kurt Christian ; Rijk, Bert ; Oberforster, Michael ; Kalyada, Valery ; Khitrykau, Maksim ; Gobin, Anne ; Kirchev, Hristofor ; Manolova, Vanya ; Manolov, Ivan ; Trnka, Mirek ; Hlavinka, Petr ; Paluoso, Taru ; Peltonen-Sainio, Pirjo ; Jauhiainen, Lauri ; Lorgeou, Josiane ; Marrou, Hélène ; Danalatos, Nikos ; Archontoulis, Sotirios ; Fodor, Nándor ; Spink, John ; Roggero, Pier Paolo ; Bassu, Simona ; Pulina, Antonio ; Seehusen, Till ; Uhlen, Anne Kjersti ; Żyłowska, Katarzyna ; Nieróbca, Anna ; Kozyra, Jerzy ; Silva, João Vasco ; Maçãs, Benvindo Martins ; Coutinho, José ; Ion, Viorel ; Takáč, Jozef ; Mínguez, M.I. ; Eckersten, Henrik ; Levy, Lilia ; Herrera, Juan Manuel ; Hiltbrunner, Jürg ; Kryvobok, Oleksii ; Kryvoshein, Oleksandr ; Boogaard, Hendrik ; Groot, Hugo de; Lesschen, Jan Peter ; Bussel, Lenny van; Wolf, Joost ; Zijlstra, Mink ; Loon, Marloes P. van; Ittersum, Martin K. van - \ 2018
European Journal of Agronomy 101 (2018). - ISSN 1161-0301 - p. 109 - 120.
Barley - Crop modelling - Grain maize - Nitrogen - Wheat - Yield potential

Europe accounts for around 20% of the global cereal production and is a net exporter of ca. 15% of that production. Increasing global demand for cereals justifies questions as to where and by how much Europe's production can be increased to meet future global market demands, and how much additional nitrogen (N) crops would require. The latter is important as environmental concern and legislation are equally important as production aims in Europe. Here, we used a country-by-country, bottom-up approach to establish statistical estimates of actual grain yield, and compare these to modelled estimates of potential yields for either irrigated or rainfed conditions. In this way, we identified the yield gaps and the opportunities for increased cereal production for wheat, barley and maize, which represent 90% of the cereals grown in Europe. The combined mean annual yield gap of wheat, barley, maize was 239 Mt, or 42% of the yield potential. The national yield gaps ranged between 10 and 70%, with small gaps in many north-western European countries, and large gaps in eastern and south-western Europe. Yield gaps for rainfed and irrigated maize were consistently lower than those of wheat and barley. If the yield gaps of maize, wheat and barley would be reduced from 42% to 20% of potential yields, this would increase annual cereal production by 128 Mt (39%). Potential for higher cereal production exists predominantly in Eastern Europe, and half of Europe's potential increase is located in Ukraine, Romania and Poland. Unlocking the identified potential for production growth requires a substantial increase of the crop N uptake of 4.8 Mt. Across Europe, the average N uptake gaps, to achieve 80% of the yield potential, were 87, 77 and 43 kg N ha−1 for wheat, barley and maize, respectively. Emphasis on increasing the N use efficiency is necessary to minimize the need for additional N inputs. Whether yield gap reduction is desirable and feasible is a matter of balancing Europe's role in global food security, farm economic objectives and environmental targets.

Prospect for increasing grain legume crop production in East Africa
Loon, Marloes P. van; Deng, Nanyan ; Grassini, Patricio ; Rattalino Edreira, Juan I. ; Wolde-meskel, Endalkachew ; Baijukya, Frederick ; Marrou, Hélène ; Ittersum, Martin K. van - \ 2018
European Journal of Agronomy 101 (2018). - ISSN 1161-0301 - p. 140 - 148.
Chickpea - Common bean - Cowpea - Food self-sufficiency - Groundnut - Legumes - Pigeonpea - Sub-Saharan Africa - Yield gap - Yield potential

Agricultural production in East Africa (E-Afr) has to increase drastically to meet future food demand. Yield gap assessment provides important information on the degree to which production can be increased on existing cropland. Most research on yield gap analysis has focussed on cereal crops, while legumes have received less attention despite of their relatively large area, and their importance as source of protein in smallholder farming systems in E-Afr. The objectives of this study were to (i) estimate water-limited yield potential (Yw) and yield gaps (Yg) for major grain legume crops in E-Afr, and (ii) estimate how narrowing the current legume Yg can contribute to food self-sufficiency by the year 2050. We focussed on Ethiopia, Kenya, and Tanzania, and five legumes crops including chickpea, common bean, cowpea, groundnut, and pigeonpea. A bottom-up approach which entails that local weather, soil and agronomic data was used as input for crop modelling (SSM-legumes) in a spatial framework, to estimate Yw, actual on-farm yield (Ya), and Yg from local to regional scale. Future legume self-sufficiency was assessed for 2050 demand assuming different Yg closure scenarios. On average, Ya was 25% of Yw across all legume-county combinations, being 15% for Kenya, 23% for Tanzania and 41% for Ethiopia. On average, common bean had the largest Yg of 2.6 Mg ha−1and chickpea the smallest (1.4 Mg ha−1). Closure of the exploitable Yg (i.e., 80% of Yw) can help to meet future legume demand in both Kenya and Tanzania, while it seems not to be sufficient in Ethiopia.

Towards a coordination of European activities to diagnose and manage insect diseases in production facilities
Eilenberg, J. ; Oers, M.M. van; Jensen, A.B. ; Lecocq, A. ; Maciel-Vergara, G. ; Santacoloma, L.P.A. ; Loon, J.J.A. van; Hesketh, H. - \ 2018
Journal of Insects as Food and Feed 4 (2018)3. - ISSN 2352-4588 - p. 157 - 166.
Diagnostic service - Europe - Insect pathogen - Insect pathogen management - Insect production

The rapid increase in insect production for food and feed both in Europe and elsewhere in the world has led to a need for a coordinated action to assist producers in the diagnosis and management of insect diseases in production stock. Diseases caused by viruses, bacteria, fungi, protozoa and other insect pathogens can be detrimental for reared insects and may cause significant economic loss to producers. Here, we suggest how academia, commercial companies and other insect producers can jointly develop best practice for diagnosing insect diseases early and thereby manage such diseases efficiently. First, we analyse different ways of transmission of insect diseases in closed and semi-closed production facilities. Thereafter we describe four recent cases where companies have requested advice about insect pathogens in their insect stock namely: with giant mealworm Zophobas morio, yellow mealworm Tenebrio molitor, house cricket Acheta domesticus, and with lesser mealworm Alphitobius diaperinus. Our experience dealing with these cases gave us insight to suggest how we should coordinate European activities to establish a service to diagnose and provide advice, and how different European laboratories specialised in insect pathology should collaborate. An important issue will be to educate a new generation of insect pathologists, who with a combination of classical insect pathology methods and the most modern tools can become professionals in diagnosing and managing the various types of insect pathogens.

Insects: Key biological features
Eilenberg, Jørgen ; Loon, Joop J.A. van - \ 2018
In: Edible Insects in Sustainable Food Systems / Halloran, Afton, Flore, Roberto, Vantomme, Paul, Roos, Nanna, Springer International Publishing - ISBN 9783319740102 - p. 3 - 15.

In this chapter, we present a brief introduction to the biology of insects, the arthropod class Insecta. We describe diversity of insects and how their bodies are structured. We also provide information about key biological features, starting with the insect exoskeleton, its structure and function. Furthermore, the insect gut and its functions are explained as well as insect growth and development. We end by describing considerations and methods for insect collecting and sampling in the field to initiate and sustain insect rearing.

Influence of larval density and dietary nutrient concentration on performance, body protein, and fat contents of black soldier fly larvae (Hermetia illucens)
Barragan-Fonseca, Karol B. ; Dicke, Marcel ; Loon, Joop J.A. van - \ 2018
Entomologia Experimentalis et Applicata 166 (2018)9. - ISSN 0013-8703 - p. 761 - 770.
detritivory - diet quality - Diptera - growth - nutritional value - ration - Stratiomyidae - survival

Performance and body composition of insect larvae depend on quality and quantity of their diet, and on biotic factors such as larval density. We investigated the effect of dietary nutrient concentration and larval rearing density on survival, development, growth, and protein and fat contents of larvae of the black soldier fly (BSF), Hermetia illucens L. (Diptera: Stratiomyidae). Neonate larvae were fed with a low (NC1), intermediate (NC2), or high nutrient concentration (NC3), and with four rearing densities (50, 100, 200, or 400 larvae per container). Two feeding regimes (FR) were tested: in FR1, the amount of diet added during the experiment was based on the visually estimated larval mass present, whereas in FR2, a fixed feeding ration of 0.6 g of food per larva was applied at the start. FR1 resulted in food limitation, resulting in significantly lower body crude protein content on diet NC1 than on NC2 at larval densities 100 and 200. Larval crude fat content was higher on diets with higher nutrient concentration and at lower larval densities. For FR2, development time was shorter on diets with higher nutrient concentration and at lower larval densities. Individual larval weight and total larval yield increased with higher nutrient concentration at all four larval densities. At lower nutrient concentration, higher larval density resulted in higher individual larval weight and total larval yield, revealing an interaction between larval density and dietary quality. Larval crude protein content was higher at lower densities and lower nutrient concentration. Larval crude fat was higher at higher larval densities and nutrient concentrations. This study indicates that larval protein content is regulated within narrow limits, whereas larval crude fat content is strongly affected by nutrient concentration and by larval density.

Insects as sources of iron and zinc in human nutrition
Mwangi, Martin N. ; Oonincx, Dennis G.A.B. ; Stouten, Tim ; Veenenbos, Margot ; Melse-Boonstra, Alida ; Dicke, Marcel ; Loon, Joop J.A. Van - \ 2018
Nutrition Research Reviews 31 (2018)2. - ISSN 0954-4224 - p. 248 - 255.
Anaemia - Anti-nutritional factors - Bioavailability - Food preparation methods - Insects - Iron - Zinc

Dietary deficiencies in Fe and Zn are globally widespread, causing serious health problems such as anaemia, poor pregnancy outcomes, increased risk of morbidity and mortality, stunted growth and impaired physical and cognitive development. Edible insects, of which a diversity of over 2000 species is available, are dietary components for about 2 billion individuals and are a valuable source of animal protein. In the present paper, we review the available information on Fe and Zn in edible insects and their potential as a source of these micronutrients for the rapidly growing human population. The levels of Fe and Zn present in eleven edible insect species that are mass-reared and six species that are collected from nature are similar to or higher than in other animal-based food sources. High protein levels in edible insect species are associated with high Fe and Zn levels. Fe and Zn levels are significantly positively correlated. Biochemically, Fe and Zn in insects occur predominantly in non-haem forms, bound to the proteins ferritin, transferrin and other transport and storage proteins. Knowledge gaps exist for bioavailability in the human alimentary tract, the effect of anti-nutritional factors in other dietary components such as grains on Fe and Zn absorption and the effect of food preparation methods. We conclude that edible insects present unique opportunities for improving the micronutrient status of both resource-poor and Western populations.

Data from: Symbiotic polydnavirus and venom reveal parasitoid to its hyperparasitoids
Zhu, F. ; Cusumano, Antonino ; Bloem, J. ; Weldegergis, B.T. ; Nunes Villela, A. ; Fatouros, N.E. ; Loon, J.J.A. van; Dicke, M. ; Harvey, Jeffrey A. ; Vogel, Heiko ; Poelman, E.H. - \ 2018
multitrophic interactions - plant-mediated interaction network - herbivore saliva - herbivore-induced plant volatiles - parasitic wasp - Cotesia glomerata - Lysibia nana - Pieris brassicae - Brassica oleracea
Symbiotic relationships may provide organisms with key innovations that aid in the establishment of new niches. For example, during oviposition, some species of parasitoid wasps, whose larvae develop inside the bodies of other insects, inject polydnaviruses into their hosts. These symbiotic viruses disrupt host immune responses, allowing the parasitoid’s progeny to survive. Here, we show that symbiotic polydnaviruses also have a downside to the parasitoid’s progeny by initiating a multi-trophic chain of interactions that reveals the parasitoid larvae to their enemies. These enemies are hyperparasitoids that use the parasitoid progeny as host for their own offspring. We found that the virus and venom injected by the parasitoid during oviposition, but not the parasitoid progeny itself, affected hyperparasitoid attraction towards plant volatiles induced by feeding of parasitized caterpillars We identified activity of virus-related genes in the caterpillar salivary gland. Moreover, the virus affected the activity of elicitors of salivary origin that induce plant responses to caterpillar feeding. The changes in caterpillar saliva were critical in inducing plant volatiles that are used by hyperparsitoids to locate parasitized caterpillars. Our results show that symbiotic organisms may be key drivers of multi-trophic ecological interactions. We anticipate that this phenomenon is widespread in nature, because of the abundance of symbiotic microorganisms across trophic levels in ecological communities. Their role should be more prominently integrated in community ecology to understand organization of natural and managed ecosystems as well as adaptations of individual organisms that are part of these communities.
Expression of protocadherin gamma in skeletal muscle tissue is associated with age and muscle weakness
Hangelbroek, R.W.J. ; Fazelzadeh, P. ; Tieland, C.A.B. ; Boekschoten, M.V. ; Hooiveld, G.J.E.J. ; Duynhoven, J.P.M. van; Timmons, James ; Verdijk, L. ; Groot, C.P.G.M. de; Loon, L.J.C. van; Müller, M.R. - \ 2018
GSE117525 - Homo sapiens - PRJNA482398
The skeletal muscle system plays an important role in the independence of older adults. In this study we examine differences in the skeletal muscle transcriptome between healthy young and older subjects and (pre‐)frail older adults. Additionally, we examine the effect of resistance‐type exercise training on the muscle transcriptome in healthy older subjects and (pre‐)frail older adults. Baseline transcriptome profiles were measured in muscle biopsies collected from 53 young, 73 healthy older subjects, and 61 frail older subjects. Follow‐up samples from these frail older subjects (31 samples) and healthy older subjects (41 samples) were collected after 6 months of progressive resistance‐type exercise training. Frail older subjects trained twice per week and the healthy older subjects trained three times per week. At baseline genes related to mitochondrial function and energy metabolism were differentially expressed between older and young subjects, as well as between healthy and frail older subjects. Three hundred seven genes were differentially expressed after training in both groups. Training affected expression levels of genes related to extracellular matrix, glucose metabolism, and vascularization. Expression of genes that were modulated by exercise training was indicative of muscle strength at baseline. Genes that strongly correlated with strength belonged to the protocadherin gamma gene cluster (r = −0.73). Our data suggest significant remaining plasticity of ageing skeletal muscle to adapt to resistance‐type exercise training. Some age‐related changes in skeletal muscle gene expression appear to be partially reversed by prolonged resistance‐type exercise training. The protocadherin gamma gene cluster may be related to muscle denervation and re‐innervation in ageing muscle.
The potential of BRIGAID’s Testing and Implementation Framework (TIF) as a tool to promote Nature Based Solutions
Loon-Steensma, J.M. van - \ 2018
Geophysical Research Abstracts 20 (2018). - ISSN 1029-7006
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