PTDC/AGR-TEC/3049/2014
Mara Elga Medeiros Braga
FCT - Foundation for Science and Technology
165.624,00 €
01/07/2016 to 01/05/2020
The pine wood nematode (PWN), Bursaphelenchus xylophilus, is the causative agent of pine wilt disease (PWD), which is causing major losses in coniferous forests around the world. Pine trees (Pinus) are the main hosts of PWN, and transmission from one host tree to another requires an insect vector. Cerambycids of the genus Monochamus are considered the most important vectors, with M. galloprovincialis being the only vector in Portugal. In addition to the ecological impacts associated with the destruction of the pine forest, the MPN is responsible for huge economic impacts in Portugal and, in the future, could become a real threat to the whole of Eurasia and North America. These economic impacts are mainly related to the loss of timber, restrictions/reduction of trade in timber and derived products, and costs associated with additional phytosanitary procedures and actions to control PWN.
This multidisciplinary project aims to develop new and more efficient phytochemical-based formulations for the control of the PWN vector insect. Phytochemicals can be alternative active ingredients (AIs) to pesticides, as they are generally safer for the environment and human health than traditional synthetics. A large number of different plant secondary metabolites (such as essential oils, phenolics, quinones, tannins, etc.) have already been tested as effective attractants/repellents for the PWN vector. However, further research is still needed to obtain formulations containing these attractive or repellent phytochemicals with field-proven efficacy, prolonged action, ease of application and reasonable cost.
Formulations based on biodegradable polymer monoliths and/or particles, loaded with specific and selective volatile AIs or mixtures thereof, were developed. Selected biodegradable polymers were used, such as poly(caprolactone) (PCL) and its biocomposites, as well as chitosan. The incorporation of AIs into these types of biopolymer monoliths/particles allowed for their controlled, prolonged and effective release.
Two different product concepts were explored: (i) commercially available trap baits to be placed in the forest, containing attractant monoliths and/or prolonged-release particles; (ii) repellent prolonged-release particles to be spread on wood or selected areas. The polymer monoliths were produced by mixing/foaming with supercritical carbon dioxide, while the particles were prepared by solvent evaporation from oil/water (o/w) emulsions. Both techniques are advantageous as they allow materials to be processed at relatively low temperatures, thus avoiding the degradation of any thermolabile AIs involved and promoting higher AIs loading efficiencies. The total/relative composition of the AIs, the biopolymers (and their molecular weights) and the process conditions were varied to obtain monoliths/particles with different physical and degradation/release properties and, ultimately, to optimize the performance of the final product. All the materials obtained were chemically and physically characterized using a wide range of analytical techniques. Experimental determination and computational modeling of the controlled release of AIs (over time) were carried out and correlated with the formulation variables and processing conditions.
The concepts and methodologies of Engineering Product Quality (EPQ) provided the unifying thread of the project, promoting the definition of appropriate product performance metrics and their target values (necessarily including the reduction in vector prevalence), which guided the detailed definition of the experimental tests carried out. Furthermore, an EPQ approach implies an integrated perspective on product/process development and the associated management of the information, tests and models involved. To the best of our knowledge, this project will be the first systematic effort to prepare controlled/prolonged-release systems of natural and biodegradable origin of attractive/repellent volatile AIs for the control of the PWN vector insect.
- PRODEQ - University of Coimbra:
- Mara Elga M. Braga
- Hermínio C. de Sousa
- Marisa C. Gaspar
- Fernando Pedro Martins Bernardo
- Ana Antunes Dias
- Maria da Graça Rasteiro
- Inês Seabra
- João Leocádio
- Rita Chim
- University of Coimbra:
- Isabel Abrantes
- Luís Fonseca
- Isabel Luci Pisa Mata da Conceição
- INIAV:
- Edmundo Sousa
- Pedro Naves
Scientific Articles
1. M.C. Gaspar, B. Agostinho, L. Fonseca, I. Abrantes, H.C. de Sousa, M.E.M. Braga. Impact of the pinewood nematode on naturally-emitted volatiles and scCO2 extracts from Pinus pinaster branches: a comparison with P. pinea. J. of Supercritical Fluids 159 (2020) 104784. https://doi.org/10.1016/j.supflu.2020.104784
2. M.C. Gaspar, H.C. de Sousa, I.J. Seabra, M.E.M. Braga. Environmentally-safe scCO2 P. pinaster branch extracts: Composition and properties. Journal of CO2 Utilization, 37 (2020) 74-84. https://doi.org/10.1016/j.jcou.2019.11.027
Master's Theses
- Vanessa Monteiro Leal, Development of formulations based on attractants/repellents to control the insect vector of pinewood nematode (PWN).
Department of Chemical Engineering - FCT - University of Coimbra, under the supervision of Mara E. M. Braga and Hermínio de Sousa. Defense 27 September 2018; http://hdl.handle.net/10316/86692
- Andreia Catarina Ribeiro Madeira, Incorporation of volatile repellent compounds for the development of formulations to control insects' incident to agroforestry ecosystems. Department of Chemical Engineering - FCT - University of Coimbra, under the supervision of Mara E. M. Braga and Ana Dias. Defense in February 2019; https://estudogeral.sib.uc.pt/cris/rp/rp79515/information.html
Summer Internships
- Diana Gonçalves - Quemical Engineering, program "Estágio de Verão" - University of Coimbra, 2019.
- João Coutinho - Biomedical Engineering, program "Summer Internship" - University of Coimbra, 2019.
- Ana Rita Fernandes - Pharmaceutical Sciences, program "Summer Internship" - University of Coimbra, 2019.
- Beatriz Agostinho - Chemical Engineering, program "Summer Internship" - University of Coimbra, 2018.
- Vanessa Leal - Chemical Engineering, program "Estágio de Verão" - Universidade de Coimbra, 2017.
Communications at International Conferences
1) M.C. Gaspar, B. Agostinho, J. Leocádio, L. Fonseca, I. Abrantes, Hermínio C. De Sousa, M. E. M. Braga. Pinus pinaster and P. pinea volatile compounds: their possible action on pinewood nematode and its insect vector. International Symposium IUFRO on Pine Wilt Disease, Orléans (France), 9-13 March 2020,cancelled due to the COVID19 pandemic.
2) Fernando P. Bernardo, Mara E. M. Braga, Rita Chim. A wind tunnel method to develop products for controlled delivery of volatiles: experimental apparatus and mathematical model. 12th European Congress of Chemical Engineering (ECCE 12), Florence, Italy, 15-19 Sep 2019. https://www.aidic.it/ecce12/programma/pro.html
3) M.E.M. Braga, Porous matrices based-formulations for improvement of volatiles loading/release for insect control. V Iberoamerican Conference on Supercritical Fluids. September 02-06, 2019. Campinas, Brazil. https://www.prosciba.fea.unicamp.br/?q=node/6
4) M. C. Gaspar, B. Agostinho, L. Fonseca, I. Abrantes, H. C. de Sousa, M. E. M. Braga. Pinewood nematode and its impact on volatiles and scCO2 extracts from Pinus pinaster branches. 17th European Meeting on Supercritical Fluids (EMSF 2019) - 7th European Meeting on High Pressure Technology. Ciudad Real, Spain 8-11 Apr 2019.
5) M. C. Gaspar, H. C. de Sousa, I. J. Seabra, M. E. M. Braga. Extracting the natural insecticide abietadiene from P. pinaster branches using scCO2. 12th International Symposium on Supercritical Fluids (12th ISSF 2018), Antibes-Juan-Les-Pins, France, April 22-25, 2018. http://supflu2018.fr/sessions.php
6) M.E.M. Braga, R.Chim, F.P. Bernardo, H.C. de Sousa. Active ingredient release from porous matrices to control the insect vector of pine wilt disease. 12th International Symposium on Supercritical Fluids (12th ISSF 2018), Antibes-Juan-Les-Pins, France, April 22-25, 2018. http://supflu2018.fr/sessions.php
7) R.Chim, H.C. de Sousa, F.P.M. Bernardo, M.E.M. Braga. Dispersion of α-pinene in porous matrices for the control of the insect vector (Monochamus spp.) of the pine nematode. II Congresso Nacional das Escolas Superiores Agrárias (II CNESA), Escola Superior Agrária de Bragança, November 16-18, 2017, Elvas, Portugal.
8) L. Fonseca, C.M.N. Maleita, I. Esteves, M.E.M. Braga, I. Abrantes, H. C. de Sousa. Naphtoquinones: bionematicides for pinewood nematode eradication from wood. International Union of Forest Research Organizations (IUFRO 2017), September 18-22, 2017, Freiburg, Germany. http://iufro2017.com/
9) J. Leocádio, M.C. Gaspar, F. Bernardo, P. Naves, E. Sousa, H.C. de Sousa, M.E.M. Braga. Searching a way of controlling the Pine Wood Nematode insect vector using PCL based matrices obtained by supercritical CO2 foaming. 1st Iberian Meeting on Supercritical Fluids (EIFS 2020), Santiago de Compostela, Spain, February 18-19, 2020.
10) V. M. Leal, M. C. Gaspar, H. C. de Sousa, M. E. M. Braga. Porous matrices based-formulations for improvement of α-pinene loading and release. 17th European Meeting on Supercritical Fluids (EMSF 2019) - 7th European Meeting on High Pressure Technology. 8-11 Apr 2019, Ciudad Real, Spain.
11) P. Naves, C. Trindade, M.E.M. Braga, M.C. Gaspar, E. Sousa. Is host selection of Mediterranean pines by Monochamus galloprovincialis (Coleoptera; Cerambycidae) related with Pine Wilt Disease incidence? XI European Congress of Entomology, 2-6 July 2018, Naples- Italy. http://www.ece2018.com/poster-session/
