1a. Objectives (from AD-416)
1. Determine efficacy and residual activity of registered insecticides against chilli thrips, Bemisia tabaci, and other taxa of invasive pests. 2. Determine direct impact and residual activity of insecticides against key beneficial organisms used for biological control of thrips, Bemisia tabaci, mites, and other taxa of invasive pests. 3. Develop model pesticide rotation programs, based on residual activity, labeled restrictions on frequency of application, and impact on key beneficial arthropods.
1b. Approach (from AD-416)
The approach of this cooperative research project is to evaluate registered pesticides alone and in rotation on different floral and ornamental host plants such as knock-out roses and hawthorne for efficacy against chilli thrips (Scirtothrips dorsalis) and their impact on predatory mites, (Amblyseius swirskii and Neoseiulus californicus ) for development of BMPs. In order to minimize reliance on spinosad and the attendant problems that this poses for western flower thrips management, efficacy trails will be conducted to find additional materials for chilli thrips control and their impact on beneficials. We fully expect to find pesticides that have lost their efficacy on WFT but not to chilli thrips. Bioassays will be conducted to determine susceptibility baseline data for chilli thrips to the most important compounds. Data will be used to develop robust IPM programs and BMPs for thrips control in general and Scirtothrips dorsalis in particular.
3. Progress Report
This project is related to Objective 5: Chilli Thrips. The objective of this cooperative research project is to evaluate registered pesticides alone and in rotation on different floral and ornamental host plants for efficacy against chilli thrips and their impact on predatory mites for development of Best Management Practices (BMPs) that will benefit growers. Two chilli thrips websites are maintained by university cooperators. From July 1, 2009 to June 30, 2010, mrec.ifas.ufl.edu/lso/thripslinks.htm had a total of 13,696 visits from 8,690 unique visitors, 7,656 first time visitors and 1,034 returning visitors. From July 1, 2009 to July 7, 2010 chillithrips.tamu.edu had a total of 3,120 visits (5.64 visits / day) from 2664 absolute unique visitors. Efficacy trials from Florida and Texas expanded the list of effective pesticides for chilli thrips control to 26 with 11 different modes of action. As a result, a thrips management program for plants for planting was developed and is available through the chilli thrips website http://mrec.ifas.ufl.edu/lso/DOCUMENTS/ThripsManagementProgram_100308.pdf. Four varieties of ornamental pepper, Black Pearl, Explosive Ember, Masquerade, and Red Missile, were evaluated for use as banker plant systems for the predatory mite, Amblyseius swirskii. Laboratory bioassays were conducted to determine if the mites would survive and reproduce on a diet of pollen alone compared to commercial olive pollen and chilli thrips (preferred host). Mites reared on a diet of chilli thrips laid 33% more eggs than any of the pollen only diets but all mites developed at the same rate (12 days larvae to first instar) and had similar longevity (23 days) regardless of the diet they were reared. In greenhouse tests, predatory mites were sustained on the ornamental pepper banker plant candidates for 28 days without pollen or prey following a single release (5 gravid female mites per plant). In another variation of the greenhouse test, predatory mites were able to establish and survive on pepper plants for 35 days in the presence of prey (whiteflies, thrips, aphids) but without pollen following a single release of 5 mites/plant. In a greenhouse trial to test the thrips management program’s effect on predatory mites, mites were released (5 mites/plant) on flowering pepper plants infested with prey (whiteflies, thrips) to determine if they could establish and survive after being drenched with dinotefuran (Safari) and sprayed with spinosad (Conserve) 8 days post-release, followed by an application of chlorfenapyr (Pylon) 23 days later. Results were very promising, and indicated that the insecticide spray regime was virtually harmless to the predatory mites. All tests are being repeated to confirm results. Progress was monitored through email, conference calls, site visits to research facilities as well as stationing the postdoctoral research associate hired thru this Specific Cooperative Agreeement (SCA) in Fort Pierce.