Evaluation of the spraying of entomopathogenic nematode diluted in vinasse on <i>Stomoxys calcitrans</i> larvae (Diptera: Muscidae) under environmental conditions.

Abstract

<i>Stomoxys calcitrans</i> 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 <i>S. calcitrans</i>, 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 <i>S. calcitrans</i> 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 <i>Heterorhabditis bacteriophora</i> HP88 showed a mortality rate of 33.3%, which was not statistically different from that of the control group (38.3%). The EPNs <i>H. indica LPP30</i> and <i>H. baujardi LPP7</i> caused mortality rates of 81.7% and 73.3%, respectively; both being higher than <i>H. bacteriophora HP88</i> and the control group, but equal to each other under these conditions. It is concluded that <i>H. indica</i> LPP30 and <i>H. baujardi</i> LPP7 were effective against stable fly larvae under environmental conditions, whereas <i>H. bacteriophora</i> HP88 does not demonstrate similar efficacy.