APHIDIIDAE برآورد درصد پارازيتيسم كل با استفاده از شته هاي موميايي شده توسط پارازيتوييدهاي

Estimating Total Parasitism Through Mummified Aphids by Aphidiidae

For determination of percent parasitism of the aphid, Thelaxis suberi (Del Guercio)(Thelaxidae) parasitized by Adialytus thelaxis Stary (Aphidiidae), samples were taken from oak trees at four times in Abbas Abad, Behshahr, Mazandaran province, Iran during 1998-99. Samples were taken randomly from cutted apical shoots having 10 centimeter length. Mummified aphids were counted carefully in the laboratory. Alive aphids were dissected under a stereomicroscope and parasitoid larvae were counted. Percentage of parasitied unmummified aphids (arcsine transformation) was plotted against percentage of mummified aphids (Mp) and the linear regression model of Nm^ = - 0.82 M p+57. 3 was obtained. By incorporating estimated percentage of unmummified parasitism (Nm^) in model (2): Tp=Mp+ Nm^ total percentage of parasitism (Tp) was estimated. Therefore, by means of these models, it is not necessary to dissect aphids to determine percent parasitism. Total parasitism (Tp) could be estimated through determining merely the percent parasitism of mummified aphids.