Seasonal variation in toxicity of citral against Fasciola larva

ABSTRACTObjectiveTo test whether the larvicidal activity of citral against Fasciola varies by season.MethodsMortality of Fasciola larva in different month of year (2011–2012) in in vitro and in vivo condition were observed at 2 h, 4 h, 6 h and 8 h exposure of citral.ResultsIn vitro toxicity of citral against redia was highest in between the June to August (8 h LC50: 2.58–2.62 mg/L), whereas against cercaria 8 h LC50 was in between 3.44–2.62 mg/L. Highest in vivo toxicity against redia was noted in between June to August (8h LC50: 4.20–5.09 mg/L). The lowest toxicity was observed from November to April. The highest temperature, free carbon dioxide, and lowest pH, dissolved oxygen were observed from June to August.ConclusionsThe present study conclusively shows that varying a biotic factor can significantly alter the in vitro and in vivo toxicity of citral against sporocyst redia and cercaria larva.