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United States Department of Agriculture

Agricultural Research Service

Research Project: Discovery and Evaluation of Biological Control Agents of Medusahead Rye and Other Important Weeds of Western U.S. Rangelands

Location: Great Basin Rangelands Research

2013 Annual Report


1a.Objectives (from AD-416):
Search for candidate biological control agents of exotic, invasive weeds of the western U.S. in the Mediterranean Basin and central Asia and study the candidates’ host-specificity and impact on the target weed.


1b.Approach (from AD-416):
Natural enemies (e.g. herbivores, pathogens) will be collected on target weeds in their native range. Characteristics of the natural enemy infestation, such as relative abundance, phenology, and impact on the target weed will be recorded. Natural enemies will be reared and identified by taxonomic specialists and assessed for their potential as biological control agents through host-specificity testing on non-target plant species. A list of test plant species for medusahead rye biological control candidates has been developed and submitted to TAG (USDA-APHIS Technical Advisory Group). The primary goal of this SCA is to discover and develop candidate biological control agents that are highly host-specific and damaging to medusahead rye.


3.Progress Report:

This agreement was established in support of objective 1 of the in-house project, the goal being to facilitate foreign exploration for and preliminary testing of weed biological control agents. Field surveys were conducted for perennial pepperweed (PPW) and medusahead in Bulgaria, Italy, Serbia, and Turkey. Building on previous work conducted in the course of this agreement, progress was made in testing the host-specificity of Metaculus lepidifolii (Acari: Eriophyoidea) and development of mass-rearing methods. The biology and taxonomy of this mite were also studied in the laboratory in Italy and Serbia. Medusahead plant samples were collected for genetic analysis and long-term field surveys of ground-dwelling arthropods associated with medusahead were continued in Bulgaria.


Last Modified: 7/25/2014
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