Effects of processed kaolin on Aphis fabae and Hippodamia variegata on broad bean: A lab and field case study

The black bean aphid, Aphis fabae Scopoli, is a critical pest feeding on various host plants. This study was conducted to investigate the effect of kaolin on A. fabae and one of its natural enemies, Hippodamia variegata (Goeze). The investigation was carried out in Barkat broad bean cultivar during 2017-2019 in field and greenhouse conditions in Karaj, Iran. The experiment was conducted as a factorial randomized complete block design with four replications. Kaolin (Sepidan® WP %95) was tested at 3, 6, and 9%, and the sampling was carried out one day before application and three, six, nine, twelve, and fifteen days after application. As soon as the insects settled, kaolin foliar application began. The laboratory tests on black bean aphid showed the highest efficiency of kaolin 9% at 12 days after application, while the least was three days after application with kaolin 3%. Field trials indicated the highest efficiency of kaolin 9%, 9 days after application. Kaolin 9% caused the highest detrimental impact on H. variegata 15 days after foliar application.