Inconsequential Study on Larvicidal Efficacy of Anise and Celery Seed Extracts Indicates that Standards in Bioinsecticide Screening are Necessary

The larvicidal activity of Pimpinella anisum (anise) and Apium graveolens (celery) seed extracts was evaluated against 4th instar Aedes aegypti larvae under laboratory conditions as per WHO methodology. Preliminary screening showed anise seed extracts to be more active than celery seed extracts and hexane produced the best extract of anise seeds giving a mildly potent lethal concentration of 403.84 mg/L. Other researchers have reported higher efficacies which cannot be explained by differences in extraction method or choice of solvent. Other probable causes of efficacy variability in phytochemical potency studies are discussed and bioinsecticide screening standards are recommended.