author(s)
Annabelle V Briones and Alice G Garbo

abstract
Aqueous and ethanolic extracts from Philippine Piper nigrum L. and its pelletized form were prepared and determined its effects on the duration of egg, larval and pupal development stages of Aedes aegypti mosquitoes. Exposure of 3rd and 4th instars to the aqueous extract at 24 hours gave an LC₅₀ of 129.6 mg/L. The LC₅₀ of pelletized form of Piper nigrum L. is 137.4 mg/L while the ethanolic extract is 19.7 mg/L. Toxicity in egg hatchability and pupae showed the ethanolic extract is the most toxic at 25 mg/L. The ethanolic extract has the highest larval reduction than the aqueous extract and the pelletized form. The development of 1st instar to pupae was prolonged up to 17 days for the extracts and pelletized form as compared to the control which was only 7 days. The ethanolic extract has the lowest emergence of adult Aedes mosquitoes as compared to the aqueous and pelletized form and is the most toxic in the inhibition of adult emergence.