Biocontrol agent: Lysiphlebus ambiguus
Status in Hawaii: Lysiphlebus ambiguus, an aphidiid wasp, was originally introduced to Hawaii from southwestern Europe in 1990 to control the yellow sugarcane aphid (Sipha flava). More than 300,000 wasps were released over a four year period, but the wasp did not become established. In 1997, another strain of the wasp that parasitized Sipha maidis, a close relative of the sugarcane aphid, was obtained from Pakistan and subsequently released. This new strain quickly became established, but its effect on the sugar cane aphid has not been determined.