1Department of Plant Protection, Faculty of Agriculture, University of Urmia, Urmia, Iran,
2Sunn Pest Research Dept., Iranian Research Institute of Plant Protection, AREEO, Tehran, Iran
3Biological Control Research Dept., Iranian Research Institute of Plant Protection, AREEO, Tehran, Iran,
The predatory bug, Andrallus spinidens (F.) is one of the most important biological control agents of lepidopteran pests in the rice fields of Iran. An experiment was conducted to evaluate the effects of 4 recommended pesticides (including 3 insecticides, Trichlorofon, Matrin and Tebufenozide and 1 herbicide, Butachlor) on A. spinidens thorough a completely randomized design (CRD) replicated 6 times. The ingestion method was performed on the 4th-instar nymphs of the predator. Pesticides concentrations were prepared based on the field recommended doses. Distilled water was used as the control. Newly emerged 4th instar nymphs were confined in Petri dishes and provided with 2-ml of pesticides inside small containers for 24 h. Mortality was recorded daily until the adult emergence. Thereafter, the survived individuals were provided with distilled water and 2-3 last instar larvae of Galleria mellonella. The experiments were carried out in a growth chamber at 25 ± 0.5 °C, 70 ± 5% RH and a photoperiod of 16:8 h (L: D). Based on the total effect of IOBC classification, Trichlrofon and Matrin insecticides with 100% mortality were placed in class 4 (harmful). Similarly, Butachlor and Tebufenozide were grouped in class 2 (slightly harmful) with 59.40% and 48.59% total effect, respectively. Therefore, if field results are confirmed, Trichlrofon and Matrin insecticides are not suitable candidates for integrated pest management programs in rice when the predator is active.