The effect of diatomaceous earth of different origin, temperature and relative humidity against adults of rice weevil (Sitophilus oryzae [L.], Coleoptera, Curculionidae) in stored wheat

Helena ROJHT; Christos G. ATHANASSIOU; Bill J. VAYIAS; Nickolas KAVALLIERATOS; Željko TOMANOVIĆ; Matej VIDRIH; Katarina KOS; Stanislav TRDAN

doi:10.14720/aas.2010.95.1.14787

Authors

Helena ROJHT University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia
Christos G. ATHANASSIOU Agricultural University of Athens, Dept. of Plant Science, 75 Iera Odos, 11855 Athens, Attica, Greece 3
Bill J. VAYIAS Agricultural University of Athens, Dept. of Plant Science, 75 Iera Odos, 11855 Athens, Attica, Greece
Nickolas KAVALLIERATOS Laboratory of Agricultural Entomology, Dept. of Entomology and Agricultural Zoology, Benaki Phytopathological Institute, 8 Stefanou Delta Street, 14561 Kifissia, Attica, Greece
Željko TOMANOVIĆ University of Belgrade, Faculty of Biology, Dept. of Zoology, Studentski trg 16, SER-11000 Belgrade, Serbia
Matej VIDRIH University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia
Katarina KOS University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia
Stanislav TRDAN University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1111 Ljubljana, Slovenia

DOI:

https://doi.org/10.14720/aas.2010.95.1.14787

Keywords:

Sitophilus oryzae, diatomaceous earth, origin, stored wheat, temperature, relative humidity

Abstract

Laboratory experiments were carried out to evaluate the impact of diatomaceous earth (DE) samples of different origin with their insecticidal properties to control one of the most important primary pest in stored grain. We tested the efficacy of three local DE, from Serbia, Greece and Slovenia, and commercial formulation SilicoSec against the rice weevil, Sitophilus oryzae, adults in stored wheat. The experiments were carried out at three temperatures (20, 25 and 30 °C) and two relative humidity (RH) levels (55 and 75 %). Mortality of pest was counted 7, 14 and 21 days after exposure (DAT) at the following DE dose rates: 100, 300, 500 and 900 ppm. The mortality of adults normally increased with increasing dose rates and DAT. In all samples the mortality of rice weevil adults (dose rate 900 ppm, 21 DAT) was above 90 %, except at Slovenian DE (at 20 °C and 55 % RH) and Greek DE (at 25 °C and 75 % RH), when the mortality was 85.3 and 67.6 %, respectively. With 100 % mortality (14 DAT and at 900 ppm) the most effective was SilicoSec.