The outbreak of Henosepilachna vigintioctopunctata (F.) was noticed on a medicinal plant, Withania somnifera Dunal during 2004-05. The population level of the pest was reached its peak in August. The parasitoid Pediobius foveolatus caused $51.94%{pm}12.20%$ parasitism. The pest completed its life cycle in $20.15{pm}1.50$ days on W. somnifera. The longevity of the male and female adults of the pest was $22.07{pm}3.71;and;31.07{pm}4.38$ days, respectively. The gravid females of H. vigintioctopunctata laid an average of $287.64{pm}33.38$ eggs during their oviposition period of $10.40{pm}2.80$ days.