Automated video-tracking analysis of Agriotes obscurus wireworm behaviour before, during and after contact with thiamethoxam- and imidacloprid-treated wheat seeds.

Abstract

Limited studies have highlighted the importance of incorporating behavioural assessments into insecticide efficacy evaluations for wireworm pest control. "For this study, video tracking technology combined with a soil bioassay arena was employed to analyse the behaviour of Agriotes obscurus wireworms before, during, and after exposure to wheat seeds treated with the neonicotinoid insecticides thiamethoxam and imidacloprid at field-relevant concentrations. The analysis identified a set of behavioural key metrics for assessing the effects of these insecticides on wireworms. The results showed that these insecticides exhibited neutral attractancy towards wireworms. A brief period of feeding followed by rapid intoxication minimised damage to seeds. Furthermore, the wireworms demonstrated a specific form of behavioural resistance to neonicotinoids that did not rely on sensory input. In these insects, the rapid speed of intoxication, accompanied by drastic changes in behaviour, ensured that they received a sublethal rather than lethal dose of the insecticide. The wireworms fully recovered from all behavioural abnormalities within a week, and none died within 20 days following the exposure. In conclusion, this video tracking method provides a rapid and efficient means of assessing insecticides intended for wireworm management, offering valuable insights prior to more resource-intensive and costly field trials.