After about three months of survey work Hoddle, along with Christina Hoddle (UCR), Charlotte Causton (Charles Darwin Research Station), and Roy Van Driesche (University of Massachusetts, Amherst), concluded that the cottony cushion scale populations were very low in most areas on the Galapagos Islands.
"Pest numbers have been reduced by more than 99 percent on some native plants like mangroves, which were very susceptible to attack by cottony cushion scale," Hoddle said. "While from other rarer native plants, like Darwiniothamnus tenuifolius, the pest appears to have been completely removed."
To assess the impact of the beetle on the cottony cushion scale, Hoddle's team surveyed native plants across five different islands Santa Cruz, Isabela, Espanola, San Cristobal, and Santiago and recorded the presence and absence of cottony cushion scale and the lady bug beetle, and their densities. The team then compared the data to similar data from the same areas and in many instances, from the very same trees that had been collected before the lady bug beetle was released into the Galapagos.
"We also found no evidence that the lady bug beetle was attacking non-target species," Hoddle said. "The bug was never seen feeding on other insects in the Galapagos even when the cottony cushion scale and the non-target species were side by side on the same twig."
The cottony cushion scale project with the beetle was born in Southern California in 1888-1889 and saved California's then fledging citrus industry.
"The project in the Galapagos is an extension of the California success story," Hoddle said. "But in the Galapagos the biocontrol agent is p
|Contact: Iqbal Pittalwala|
University of California - Riverside