PLANT-BORNE COMPOUNDS AND NANOPARTICLES: CHALLENGES FOR MEDICINE, PARASITOLOGY AND ENTOMOLOGY Insecticidal effect and impact of fitness of three diatomaceous earths on different maize hybrids for the eco-friendly control of the invasive stored-product pest Prostephanus truncatus (Horn) Nickolas G. Kavallieratos 1,2 & Christos G. Athanassiou 1,3 & Gerassimos G. Peteinatos 1 & Maria C. Boukouvala 1,2,4 & Giovanni Benelli 5 Received: 27 March 2017 /Accepted: 14 June 2017 # Springer-Verlag GmbH Germany 2017 Abstract Diatomaceous earths (DEs) are able to successfully protect grain commodities from noxious stored-product insect and mite infestations; however, their effectiveness may be moderated by the grain hybrid or variety they are applied to. There is a gap of information on the comparison of the effica- cy of different DEs when are applied on different maize hy- brids against Prostephanus truncatus (Horn). Therefore, here we tested three commercially available DEs (DEA-P at 75 and 150 ppm, Protect-It at 500 ppm, and PyriSec at 500 ppm) on five different maize hybrids (Calaria, Doxa, Rio Grande, Sisco, and Studio) for the control of P. truncatus adults in terms of mortality (at 7 and 14 days), progeny production, properties of the infested maize hybrids (number and weight of kernels with or without holes, number of holes per kernel) and the adherence level of the tested DEs to the kernels. DEA- P was very effective at 75 ppm while a considerable proportion of the exposed P. truncatus adults was still alive after 14 days of exposure on all maize hybrids treated with 500 ppm of Protect-It or PyriSec, even though it was 3.3 times higher than the maximal application tested dose of DEA-P. Apart from parental mortality, DEA-P was able to reduce P. truncatus progeny production in all hybrids contrary to Protect-It or PyriSec. The adherence ratios were always higher for DEA-P than Protect-It or PyriSec to all maize hybrids. The highest numbers of kernels (or weight of kernels) without holes were noticed after their treatment with DEA-P. Doxa and Sisco performed better than Calaria, Rio Grande, or Studio based on the differences found concerning the numbers of kernels without holes at treatments with DEA-P and Protect-It. Overall, the findings of our study indicate the high potentiality of DEA-P as protectant of different maize hybrids to P. truncatus infestations at low doses, a fact that could help the eco-friendly management of this noxious species in the stored-product environment. Keywords Biosafety . Grain protectants . Progeny production . Stored maize . Hybrids Introduction The larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) is a serious insect pest of stored maize and cassava tubers in Africa (Hill 2003, Muatinte et al. 2014) and falls under regional quarantine concerns (Tyler and Hodges 2002, Myers and Hagstrum 2012). After its accidental introduction in Africa from Mesoamerica four decades ago, this species is now spread in a wide zone, which includes numerous countries in Africa (i.e., Benin, Burkina Faso, Burundi, Ghana, Guinea, Kenya, Malawi, Niger, Nigeria, Rwanda, South Africa, Tanzania, Togo, Zambia), Central Responsible editor: Philippe Garrigues * Nickolas G. Kavallieratos nick_kaval@hotmail.com 1 Laboratory of Agricultural Zoology and Entomology, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos st, 11855 Athens, Attica, Greece 2 Laboratory of Agricultural Entomology, Department of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, 8 Stefanou Delta st, 14561 Kifissia, Attica, Greece 3 Laboratory of Entomology and Agricultural Zoology, Department of Agriculture Crop Production and Rural Environment, University of Thessaly, Phytokou st, 38446 Nea Ionia, Magnissia, Greece 4 Laboratory of Organic Chemistry, Department of Chemistry, University of Ioannina, Panepistimioupolis, 45110 Ioannina, Greece 5 Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124 Pisa, Italy Environ Sci Pollut Res DOI 10.1007/s11356-017-9565-5