Diorrhabda elongata (Coleoptera: Chrysomelidae) is native to China and was introduced by USDA in May of 2001 as a biological control agent against the non-native, riparian invasive plant Tamarix ramosissima. A key question pertaining to this biological program is how will mortality affect the establishment success of D. elongata populations in the field. Post release field studies of D. elongata larval survivorship on T. ramosissima are currently underway in Owens Valley, California. Initial observations indicate that ant predation and wind are the major mortality factors encountered by larvae of this biological control agent in its new environment. To further explore the impact of ants on larval mortality, larval cohorts were monitored in the field. Cohorts of 40 first instar larvae were placed on separate T. ramosissima branches that were either exposed to or protected from ants. Larval survivorship from cohorts protected from ants was compared to those exposed to predation. Preliminary results indicate that over a three day period, 58% of the larvae are lost from branches where ants are excluded and 93% from branches exposed to ants.
Species 1: Coleoptera Chrysomelidae Diorrhabda elongata
Keywords: Biological control
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA