An Australian ladybird on the Galapagos Islands is succeeding in controlling the invasive cottony cushion scale (Icerya purchasi). This is according to results of work carried out by scientists Mark and Christina Hoddle of the University of California, Riverside, and Roy Van Driesche of the University of Massachusetts, Amherst, in cooperation with Charlotte Causton, adjunct at the Charles Darwin Foundation, CDF staff, the Galapagos National Park Service, and the Galapagos Inspection and Quarantine System (SICGAL) during the last three months of 2009.
While work is still ongoing, data collected during the first phase of the study suggest that the mariquita or Vedalia beetle, an Australian ladybird (Rodolia cardinalis) has survived and spread, while suppressing the cottony cushion scale on many native Galapagos plants, including the white mangrove, Acacias, and Scalesia. However, there are several plant species still being affected by the cottony cushion scale, and further study is required to determine why the mariquita is not effective on these host plants. In addition to being effective, the project has been safe, as no evidence from field observations or the large cage studies was found of attack by R. cardinalis on non-target insects.
While work is still ongoing, data collected during the first phase of the study suggest that the mariquita or Vedalia beetle, an Australian ladybird (Rodolia cardinalis) has survived and spread, while suppressing the cottony cushion scale on many native Galapagos plants, including the white mangrove, Acacias, and Scalesia. However, there are several plant species still being affected by the cottony cushion scale, and further study is required to determine why the mariquita is not effective on these host plants. In addition to being effective, the project has been safe, as no evidence from field observations or the large cage studies was found of attack by R. cardinalis on non-target insects.
