In recent years, the pest status of Liriomyza trifolii (Burgess) and L. huidobrensis (Blanchard) (Diptera: Agromyzidae) has changed in California, as well as other areas of the world. In California, L. huidobrensis has become the predominant Liriomyza species in valleys along the central coast, while L. trifolii remains the predominant species in southern California. To investigate possible rea...