Spores of Trichoderma strains sprayed over Acanthoscelides obtectus and Phaseolus vulgaris L. beans: Effects in the biology of the bean weevil  Alvaro Rodríguez-Gonz  alez a, * , María Piedad Campelo a , Alicia Lorenzana a , Sara Mayo-Prieto a ,  Oscar Gonz  alez-L  opez a , Samuel  Alvarez-García a , Santiago Guti  errez b , Pedro Antonio Casquero a a Grupo Universitario de Investigaci on en Ingeniería y Agricultura Sostenible (GUIIAS), Instituto de Recursos Naturales, Medio Ambiente y Biodiversidad (INMARENBIO), Escuela de Ingeniería Agraria y Forestal (EIAF), Universidad de Le on, 24071, Avenida de Portugal 41, Le on, Spain b  Area de Microbiology, Escuela de Ingeniería Agraria y Forestal (EIAF) (Campus de Ponferrada), Universidad de Le on, 24401, Avenida de Astorga s/n, Ponferrada, Spain article info Article history: Received 27 May 2020 Received in revised form 12 June 2020 Accepted 20 June 2020 Available online xxx Keywords: Attraction Behaviour Biological control Damaged beans Repellence Storage pest abstract Acanthoscelides obtectus is an insect pest feeding on common beans Phaseolus vulgaris. Three strains of Trichoderma harzianum and one strain of Trichoderma citrinoviride were sprayed on insect adults and Phaseolus vulgaris L. beans in order to investigate the efficiency of the fungi in combating Acanthoscelides obtectus insect pest. The strains E20, T34, and T019 exhibited high virulence on adults. Spores of T34 isolate were more attractant for both sexes and showed a higher mortality rate on insects in contact with treated beans than the other strains. Treated beans showed a lower weight loss compared to the un- treated ones. T019 and T008 treatments resulted in a lower weight loss of beans than the other fungal strains. Daily insect emergence was reduced in treated beans. The strain T34 accounted for the lowest daily emergence of insects. T008, T019, and E20 exhibited the capacity to repel insects, which resulted in a reduction of damaged beans as well as a lower number of holes per bean. Trichoderma strains were re- isolated from insects’ cadavers extracted from treated beans. Regarding these results, T34 strain could be used in the control of A. obtectus adults due to its high lethal effect. Additionally, T008 and T019 strains, showing good results in terms of insecticidal activity, insect repellency, reduction of damaged beans and lower weight loss of beans, could also be used for the biological control of A. obtectus. © 2020 Elsevier Ltd. All rights reserved. 1. Introduction Insect species belonging to Coleoptera represent the most common and damaging pest affecting stored-product (Hern andez- Lambra~ no et al., 2015). Popularly known as the bean weevil, Acanthoscelides obtectus Say (Coleoptera: Chrysomelidae: Bruchi- nae), is an insect causing losses on wild and cultivated common bean (Phaseolus vulgaris L.) (Paul et al., 2009; Thakur, 2012; Vilca Mallqui et al., 2013). The attack of A. obtectus over P. vulgaris be- gins on the field and continues during the storage period. The greatest losses occur in the latter phase (Baier and Webster, 1992). A. obtectus populations grow exponentially on untreated beans, being able to wipe out entire crops within a few months (Golebiowski et al., 2008). On the other hand, the use of insecticidal treatments causes ecosystem damages, toxic effects for humans and other living or- ganisms, and result in the development of resistant pest varieties (Kumar et al., 2011). These problems and limitations have encour- aged the development of more sustainable alternatives for pest management and control (Regnault-Roger et al., 2012; Rodríguez- Gonz alez et al., 2019a,b). Among these new strategies, identifying biological control agents with alternative activities should be a priority, searching for those with higher selectivity and a lower persistence in the envi- ronment (Rodríguez-Gonz alez et al., 2017). The use of microor- ganisms in the control of pests, crop diseases, and weeds is now a rapidly growing trend. As a result, there is currently an increasing number of available commercial products based on the use of * Corresponding author. E-mail address: alrog@unileon.es (  A. Rodríguez-Gonz alez). Contents lists available at ScienceDirect Journal of Stored Products Research journal homepage: www.elsevier.com/locate/jspr https://doi.org/10.1016/j.jspr.2020.101666 0022-474X/© 2020 Elsevier Ltd. All rights reserved. Journal of Stored Products Research 88 (2020) 101666