Seasonal variation in toxicity of citral against Fasciola larva

Abstract

Objective: To test whether the larvicidal activity of citral against Fasciola varies by season. Methods: Mortality 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. Results: In 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. Conclusions: The 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.

Keywords

• Fasciolosis
• Sporocyst
• Redia
• Cercaria
• Citral
• Lymnaea acuminata