RIVERSIDE, Calif. The Galapagos Islands, made famous by Charles Darwin, have a unique biota now highly threatened by invasive species because of increased tourism and population growth. Indeed, alien or exotic insects today constitute 23 percent of the Galapagos insect fauna. One of these insect invaders is the cottony cushion scale, a sap sucking bug native to Australia.
Capable of infesting many woody ornamentals and crops, the cottony cushion scale decreases the vitality of its host by sucking phloem sap from the leaves, twigs, branches, and trunk. But natural enemies, such as the lady bug beetle, Rodolia cardinalis, can bring the cottony cushion scale under control in a short time a form of pest suppression called biocontrol.
In fall 2009, entomologist Mark Hoddle, the director of the Center for Invasive Species at the University of California, Riverside, and colleagues visited the Galapagos Islands to assess the impact and safety of the lady bug beetle that had been released in 2002 to suppress the cottony cushion scale.
"Populations of cottony cushion scale in 2002 were so high and spread across so many islands that several endemic and native plant populations were thought to be going into decline because of heavy infestations," said Hoddle, also a biocontrol specialist in the Department of Entomology.
Combating the cottony cushion scale was a joint effort between the Charles Darwin Research Foundation and the Galapagos Islands National Park Service, which neighbors the foundation on the island of Santa Cruz in the Galapagos.
"Soon after release, the lady bug beetle readily established and spread," Hoddle said. "Subsequent monitoring indicated that it was having the desired effect on the cottony cushion scale populations, which wer
|Contact: Iqbal Pittalwala|
University of California - Riverside