|Wu, Jinquan - University Of Delaware|
|Smith, Michael - Former Ars Employee|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/26/2011
Publication Date: N/A
Interpretive Summary: Control of the Asian Longhorned Beetle (ALB) currently relies upon removal of infested trees and the injection of trees with an insecticide. These two methods contribute to the control adult ALB, but have their limitations. More specifically, removal of infested trees may often occur after beetles have dispersed. The insecticide may not reach all parts within the injected trees at doses high enough to kill adult beetles, and it may cause beetles to stop feeding and increase dispersal. Therefore, there is a need for additional eradication methodologies. In this study, we evaluated an insecticide known to kill insects when they come in contact with the chemical. We first evaluate the toxicity of the insecticide in the lab and determined the doses that effectively kill adult ALB. We subsequently evaluated the insecticide to determine how many days the insecticide would effectively kill beetles under field conditions. Collectively, results show that Demand® CS is highly effective against adult ALB, immediately disabling adult beetles upon contact, killing adult beetles within minutes and doing so for approximately 60-90 days. Based upon these characteristics, Demand represents a new method that does not exist within the current arsenal of tools from which APHIS and other agencies draw for eradication of ALB. More specifically, Demand can be applied: (1) in areas that are otherwise inaccessible for existing eradication program operations, e.g. survey, tree injection of insecticides and removal of infested trees (reference); (2) to infested trees immediately prior their removal, thereby preventing escape of adult beetle that would otherwise disperse during the process of cutting trees (reference); and (3) in concert with artificial attractants and attractive trees (sentinel or bait trees) to provide an Attract-and-Kill strategy for early detection, rapid response and population suppression, particularly when population are at low levels and very difficult to detect by conventional methods. Demand may also complement existing rapid response strategies, specifically tree removal, by application to infested trees in the interim period between detection and removal of infested trees, thereby preventing additional attack and dispersal (reference). Demand may also complement and enhance existing prophylactic methods by kill beetles immediately upon contact, thereby insuring that beetles pose no not threat of dispersal and attack of additional trees. The feasibility of these strategies is currently being evaluated.
Technical Abstract: We evaluated the 24h contact toxicity of lambda-cyhalothrin for adult Asian longhorned beetle, Anoplophora glabripennis Motschulsky, using topical application. Results showed that beetles are sensitive to lambda-cyhalothrin: the LD50 and LD90 were 0.13639 and 0.78461µg/beetle, respectively. Residual activity of Demand® CS was evaluated in a walking bioassay: Adult beetles walked across the surface of Denier bands treated with a series of Demand® CS concentrations and exposed to the natural environment for 10, 20, 45, 69 and 90 d. Beetle mortality was recorded after 24 h. At the dosages of 150, 300, 450, and 600 mg/L, residual activity declined slowly over the 90 d test period. All dosages provided 100% mortality up to 20 d post treatment. No significant differences were detected in mortality among the dosages at each test interval until day 90 post treatment, when the 450 and 600 mg/L doses provided 100% mortality, which was significantly greater than percentage mortality provided by the 150 (20%) and 300 mg/L (50%) doses. The 1200, 1500, and 1800 mg/L doses provided 100% mortality for 158 d. Demand® CS may represent a new, alternative and/or complementary control strategy against A. glabripennis due to its high toxicity to adult A. glabripennis, its long residual activity, its rapid knock-down ability, and its potential use in specialized areas where current control strategies are not desirable or feasible.