Evaluation of the spraying of entomopathogenic nematode diluted in vinasse on Stomoxys calcitranslarvae (Diptera: Muscidae) under environmental conditions

Stomoxys calcitrans is a hematophagous dipteran known as a "stable fly", capable of parasitizing several animal species. The use of biological agents is an alternative for controlling S. calcitrans, with entomopathogenic nematodes (EPNs) being both resistant and virulent. The present study aimed to evaluate the effect of infection by EPNs subjected to spraying pressure on S. calcitrans larvae in sugarcane straw and vinasse under environmental conditions. Groups of 20 larvae of the stable fly were placed in plastic containers containing one kilogram of autoclaved soil and 200 g of sugarcane straw each. Subsequently, 200 JIs/larvae were sprayed onto the trays with larvae, and emergence traps were placed on the containers. In the control group, there were no EPNs; only vinasse was used. The experiment had three replicates and was monitored daily for 15 days. It was observed that the EPN Heterorhabditis bacteriophora HP88 showed a mortality rate of 33.3%, which was not statistically different from that of the control group (38.3%). The EPNs H. indica LPP30 and H. baujardi LPP7 caused mortality rates of 81.7% and 73.3%, respectively; both being higher than H. bacteriophora HP88 and the control group, but equal to each other under these conditions. It is concluded that H. indica LPP30 and H. baujardi LPP7 were effective against stable fly larvae under environmental conditions, whereas H. bacteriophora HP88 does not demonstrate similar efficacy.