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United States Department of Agriculture

Agricultural Research Service

Research Project: EXPLORATION FOR BIOLOGICAL CONTROL AGENTS OF DOWNEY ROSE MYRTLE RHODOMYRTUS TOMENTOSA IN ASIA

Location: Invasive Plant Research Laboratory

2013 Annual Report


1a.Objectives (from AD-416):
To find host-specific and damaging biological control agents of R. tomentosa climatically adapted for use in Florida.


1b.Approach (from AD-416):
The methods will follow standard protocols that include foreign surveys for adapted herbivores from Southeast Asia and risk assessment studies of these species to determine their safety in preparation for approval to release from state and federal regulatory agencies. Molecular taxonomy will be undertaken to help identify the origin of the USA populations of the weed. Molecular techniques will also be used to supplement laboratory research to separate closely related species if they occur and to compare the insects found in different locations in Southeast Asia.

Field surveys will include monitoring of non-target plant species growing with Rhodomyrtus in the field for any evidence of activity by targeted insects. Because of the relatively widespread occurrence of the plant in Southeast Asia, surveys will cover a range of climatic and site variables. Experienced local botanists and entomologists will be consulted wherever appropriate and identified specimens will be lodged in local collections. Evidence of parasitism of prospective agents will be investigated and this will supplement information on any seasonal variations of herbivore populations observed during regular surveys. Identification of specimens will rely on local specialists as well as group experts in the USA, particularly at the USDA/ARS Systematic Entomology Laboratory (SEL), Beltsville, Maryland.

• Conduct exploratory surveys for biological control agents of R. tomentosa to be completed in Hong Kong, provinces of southern mainland China and other countries of Asia when/where possible and to produce an inventory of potential biological control agents for all locations in the native range. • Seasonality of all agents will be investigated through surveying R. tomentosa throughout the year in the native range. • Idiophantis will be collected from Hong Kong or mainland China and shipped to IPRL quarantine in Florida. • Carea varipes will be collected from Asia and shipped/hand-carried to USDA/ARS ABCL quarantine in Brisbane Australia for biology and host range evaluations. • Locate populations of Sternuchopsis reticulatus for collection and colonization.


3.Progress Report:

This research is directly related to inhouse objective 3 - Conduct faunistic and floristic inventories to discover natural enemies that may serve as biological control agents for target weeds including, but not limited to Brazilian pepper, lygodium, downy rose myrtle, skunk vine and Chinese tallow. Additional biological control agents will be sought for species for which some control has been achieved, including melaleuca.

Quarantine research at the USDA/ARS Australian Biological Control Laboratory (ABCL) was reinitiated after permits to import insects into Australia were reissued. Exploratory field surveys in 2012/2013 continued in mainland China, Hong Kong and Thailand to locate biological control agents of Rhodomyrtus tomentosa. Surveys focused on at least two stem-boring moth species which have been collected in Hong Kong and mainland China. A specimen from Hong Kong emerged and was identified as a Cossidae moth. After many years, the tip boring weevil Sternuchopsis reticulatus was recollected from Thailand and hand carried to quarantine at ABCL in Brisbane where staff are attempting to establish a colony. Tip-boring Lepidoptera were imported into Australia from Thailand in December 2012 and again in May 2013. Larvae were Metharmostis multilineata and Idiophantis soreuta. Metharmostis multilineata has already been rejected as a biological control agent given lack of specificity. Adults of I. soreuta emerged in ABCL quarantine and colony establishment is being attempted. Various Lepidoptera defoliators, binders and leaf miners were shipped and hand carried to IPRL quarantine in Fort Lauderdale.


Last Modified: 11/26/2014
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