Pacific Pests, Pathogens and Weeds

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Summary

• Worldwide distribution. In Oceania. Australia (native), American Samoa, Cook Islands, Fiji, French Polynesia, Guam, Kiribati, New Caledonia, New Zealand, Palau, Tuvalu, Vanuatu. Preys on Icerya species.
• Eggs, red, laid on or under scales. Larvae (greyish with black spots) feed on scale eggs (in eggsac), crawlers, larvae; adults red-brown, black behind the head, covered in short white hairs.
• Important biocontrol beetle.
• Biosecurity: Need to assess risk before introduction: Icerya may be food for native species, and non-target insects may be attacked by Rodolia, although host range is narrow.
• Management: (i) avoid use of organophosphates, carbamates and synthetic pyrethroids; possible to use spinosad and abamectin if insecticides required to enhance control ; (ii) use sleeve cages to protect populations initially; control ants: (a) stomach poisons (fipronil, Amdro^®, borax), (b) growth regulators (methoprene, pyriproxyfen), (c) nerve poisons (bifenthrin, fipronil, imidacloprid). See (http://piat.org.nz/getting-rid-of-ants).