On the efficiency of entomopathogenic nematodes (Rhabditida: Heterorhabditidae and Steinernematidae) on rust red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae)

Background The rust red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae) is a serious pest of stored grains and grain products across the world. This beetle is hold a significant place in Turkey by causing damages on stored products. T. castaneum primarily attacks milled grain and its derivates. Entomopathogenic nematodes (EPNs) are regarded as extremely an important biological control agent. EPNs kills their hosts within 48 h by the bacteria they carry. Results Efficacies of 4 isolates of EPNs Steinernema carpocapsae (Tokat Bakisli 05), S. feltiae (Tokat-Emir), Heterorhabditis bacteriophora (TOK-20) and H. bacteriophora (11-KG) against T. castaneum was investigated under laboratory conditions. The experiments were carried out thrice with 10 replicates at 2 different temperatures (15 and 25 ºC). EPNs isolates were tested at 3 different concentrations (250, 500 and 1000 IJs/ml) with a pure water as control. The overall mortality caused by H. bacteriophora (Kg11) was significantly higher than the other EPN species. At 25 ºC, H. bacteriophora (Kg11) at the highest concentration (1000 IJs/ml) caused 87.6% mortality after 120 h., followed by S. carpocapsae and S. feltiae with 79.22 and 75.3% mortality rates, respectively. The mortality percentages exhibited by all nematodes’ species at both temperatures were lowest at the concentration of (250 IJs/ml). At 15 °C, H. bacteriophora (Kg11) caused (55.2%) mortality rate at the highest concentration (1000 IJs / ml) after 120 h. Conclusion The study suggested that these nematodes were efficient and could be recommended to control T. castaneum in its biological control programs.