Location: Exotic and Invasive Weeds Research
Title: Biology and host range of the moth Digitivalva delaireae as one of two candidate agents for biological control of Cape-ivy Authors
Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: June 3, 2013
Publication Date: N/A
Technical Abstract: Cape-ivy (Delairea odorata, Asteraceae), native to coastal floodplains and mountains in eastern South Africa, is an invasive vine in coastal riparian, woodland and scrub habitats in California and southern Oregon, as well as mid-elevation regions on some of the Hawaiian Islands. Cape-ivy smothers native vegetation and may impair water flow in coastal riparian areas. The Cape-ivy moth Delairea odorata (Lepidoptera: Glyphipterigidae) was selected for evaluation for biological control based on its widespread distribution in the native range, and its ability to kill leaves and entire vining stems of Cape-ivy. Among a total of 99 other plants evaluated in host range choice tests, D. delaireae fed and reproduced only on Cape-ivy. Females live approximately two weeks and lay 50 or more eggs, and the generation time of the moth is 50-60 days. In laboratory efficacy tests, one generation of infestation reduced plant growth rate, stem length and shoot and root biomass by 30 to 40%. The Cape-ivy moth, along with the Cape-ivy fly Parafreutreta regalis (Diptera: Tephritidae) has been recommended for field release by an international peer panel with members from the U.S., Canada, and Mexico, and applications to release both candidate agents in California and Oregon are currently being reviewed by U.S. regulatory agencies.