Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/29/1995
Publication Date: N/A
Citation: N/A Interpretive Summary: The landscape in the United States is dotted with many undesirable plants of foreign origin that arrived here through intentional or accidental introductions. These naturalized weeds usually lack natural enemies capable of regulating their abundance. To correct this, weed-eating insects (candidate bio-control agents) can be sought in a weed's native country and introduced into the U.S. However, before these insects can be released in the U.S., research must show that they will not attack and harm beneficial plant species. These studies involve a literature review of host-plant records of the insect, studies of the insect's biology, and determination of the insect's host range via laboratory tests. In this report, the authors show that field tests can also be used to determine the host plant range of insects under consideration for release in the U.S. In field tests, insects are exposed to the target weed and beneficial plant species in open field plots in the insect's native country. This review is timely because Government advisory groups are starting to require data from field tests to help them to decide if an insect for weed control should be released into a new country. With this review, researchers have a set of guideline for designing and conducting field tests.
Technical Abstract: Open-field tests in host-specificity determination of insects for biological control of weds allow insects to exercise free choice of test plants without the constraints associated with the use of cages. Therefore, this testing method can generate host data on candidate biocontrol agents under more natural conditions than can be obtained via cage tests. The literature makes note of 24 studies on open-field testing, involving 134 target weed species and more than 34 species of insects and one eriophyid mite. Field test data was used to support the release of 20 of these candidate agents into mew countries. Host field tests have been conducted in concert with laboratory, host-specificity tests, or in response to the results of laboratory tests. This review also provides information on experimental designs, locations, categories of test plants included, and the constraints to open-field testing.