Preliminary study on the toxicity of the strobilurin and triazole fungicides to Meteorus pulchricornis

To clarify the side effects of the strobilurin and triazole fungicides on the adult female Meteorus pulchricornis, the impact on the survivorship of M. pulchricornis when exposed to eight fungicides was assessed using the dry film residue and oral ingestion method under laboratory conditions. Results showed that the methods used had significant influence on the survival of M. pulchricornis. Among the contact tests, trifloxystrobin had the highest toxicity with the LT50 of 1.18 d. The second most toxic fungicide is penconazole with the LT50 of 1.98 d, while flutriafol showed the lowest toxicity with the LT50 up to 52.58 d. Among the ingestion experiments of the two classes of fungicides, the LT50 for the 8 fungicides were all greater than 15 d. Meanwhile, significantly negative effect on the life span of M. pulchricornis was observed except when it was exposed to flutriafol by contact tests and exposed to hexaconazole by ingestion tests. Therefore, more attention should be paid on the safety of strobilurin and triazole fungicides and especially, the impact of trifloxystrobin and penconazole on parasitoids such as M. pulchricornis in practices.