Abstract:In order to understand the influence of kairomones from diamondback moth (DBM), Plutella xylostella, on searching behavior and parasitism for egg parasitoid, Trichogramma confusum Viggiani, the contact response of parasitoid to individual compounds of 13 saturated hydrocarbons from its host egg shells and abdominal scales of P.xylostella were bioassayed in laboratory condition. The results revealed that the highest parasitoid activity index (PAI) of 79.67 was observed in the egg cards treated with hexadecane than the others. Irrespective of concentration, this was followed by hexatriacontane with the PAI of 67.50, while docosane showed the weakest attraction to T.confusum with the lowest PAI of 3.00. Hexatriacontane caused the highest parasitism of 183.17 followed by hexadecane with the PAI of 53.00, while docosane exhibited the minimum parasitism of 0.67. The highest parasitism of T.confusum over 20% was found in the egg cards treated with hexadecane, heptadecane, pentacosane, heptacosane, octacosane and hexatriacontane, whereas the highest parasitism under 5% was found in the egg cards treated with docosane.