The azalea lace bug, Stephanitis pyrioides, is a serious pest of azaleas and rhododendrons which is often controlled by systemic insecticides. However, the efficacy of softer approaches such as biological control and water sprays against this pest on rhododendrons is unknown. Therefore, we tested the commercially available green lacewing predator, Chrysoperla rufilabris, and water sprays on lace bug infestation in one laboratory and four field trials. First, 2nd instar predator larvae were confirmed to consume lace bug nymphs and sometimes adults. Second, tapping predator larvae from hexcel units over dry leaves of potted rhododendrons and shaking loose eggs over wet leaves were reliable application methods. Third, predator larvae released onto potted rhododendrons lowered lace bug counts for two weeks. Fourth, after four bi-weekly applications, plants receiving egg cards or water-sprays had reduced lace bug counts and fewer damaged leaves than control plants. Fifth, landscape plants receiving the sequential combination of water spray followed by predator egg releases had 44 to 90% lower lace bug abundance and fewer damaged leaves than the control. After lace bugs were initially dislodged, hatching predators might have consumed hatching lace bugs. Index words: biological control, Chrysoperla rufilabris (Burmeister), mechanical control, rhododendron, Stephanitis pyrioides (Scott) Species used in this study: Azalea lace bug (Stephanitis pyrioides Scott), green lacewing (Chrysoperla rufilabris Burmeister), Rhododendron (Rhododendron spp.)

Critical innovative technology is needed to increase application efficiencies and reduce uncertainties for conventional pesticide sprayers to achieve real cost benefits with new pesticide application strategies for tree crop producers, consumers and the environment. A precision air-assisted sprayer was developed to apply appropriate variable amounts of pesticides for orchard and ornamental nursery applications. The sprayer integrated a highspeed laser scanning sensor, a custom-designed signal processing program, an automatic flow controller, pulse-width-modulated variable-rate nozzles and a multi-port air-assisted delivery system. The accuracy and consistency of the sprayer to assess tree canopy structures and the effects of sprayer travel speeds and canopy structures on the uniformity of spray deposition and coverage inside canopies were evaluated with multiple target species in three commercial nurseries and an orchard. The spray quality inside canopies and off-target losses were compared with conventional constant-rate applications. Pest control efficacy of the sprayer was also tested in commercial nurseries in three different states. Laboratory and field tests demonstrated that the laser-guided variable-rate sprayer had the capability to automatically control spray outputs of individual nozzles to match canopy characteristics and occurrence in real time. With comparable pest control efficacies during a growing season, the laser-guided sprayer reduced pesticide use by 46% to 68%, airborne spray drift by up to 70% to 100%, and spray loss to the ground and through the space between trees by 71% to 85%. Therefore, this new generation of precision sprayers will prevent excessive pesticide use and reduce production costs, worker exposure to pesticide risks, and adverse environmental contamination.

Research on the field efficacy of two smart sprayer prototypes is being conducted in Oregon nurseries. The goal of this research is to develop sprayers that use technology to detect crop size and presence, and that vary the flow of pesticides from nozzles based on this information during applications. The first prototype, a modified hydraulic vertical boom system on a high ground clearance sprayer (TR-4 Tracker; GK Machine, Inc., Donald, OR), utilizes ultrasonic sensors to detect the size and volume of liner-sized plants. One side of the sprayer (three sections) was retrofitted with an intelligent spray system, and the other side (three sections) remained as a conventional spray system which allowed paired comparisons between intelligent and conventional treatments simultaneously for the field trials. Field tests during 2011 and 2012 evaluated insect and disease control (powdery mildew, Phyllactinia guttata, on ‘Crimson Sentry’ Norway maple and the aphid species, Myzocallis walshii, and M. granovskyi, on red oak) and determined no difference in control between the hydraulic smart sprayer and conventional sprayer. The second prototype is an air-assisted system utilizing a laser scanning sensor to measure plant structure and foliage density. There were four trials to evaluate field efficacy of the smart sprayer during the 2013 field season. Trial one compared variable flow of the smart sprayer versus constant rate of a conventional air blast sprayer application for control of powdery mildew, P. guttata, on ‘Crimson Sentry’ Norway maple. Trial two compared variable flow versus constant rate application (sensor off) of the smart sprayer for control of honeylocust pod gall midge, Dasineura gleditchiae on ‘Sunburst’ honeylocust trees. Trial three compared variable flow of the smart sprayer versus constant rate of a conventional air blast sprayer application for control of Pacific Coast pear rust, Gymnosporangium libocedri, on two-year ‘Jack’ flowering pears. Trial four compared variable flow versus constant rate application (sensor off) of the smart sprayer for control of Pacific Coast pear rust, G. libocedri, on three-year ‘Jack’ flowering pears.

In July 1999, adult stages of root weevils were established in 1-gal containers planted with Rhododendron `PJM.' Each pot was inoculated with one black vine weevil, three rough strawberry root weevils, and four strawberry root weevils. On 12 July, insecticide spray treatments were applied. Treatments were evaluated for percent adult mortality at 7 and 14 days after treatment (DAT). Black vine weevils were more sensitive to the insecticides studied than either strawberry root weevil or rough strawberry root weevil. There was considerable mortality of the black vine weevils and rough strawberry root weevils in the untreated plots by 14 DAT. Talstar Flowable (bifenthrin), Alta (deltamethrin), Topside (lamda cyhalothrin), and CGA 293 343 (thiamethoxam) all gave 100% control 7 DAT. Additionally, Closure (bendiocarb) and acephate gave 75% or better control at 7 DAT. Rough strawberry root weevil had 100% mortality in only the Alta-treated plots at 7 DAT, followed by 93% and 80% mortality in Topside and acephate-treated plots, respectively. Mortality of the strawberry root weevils in the untreated plots by 14 DAT remained relatively low. Strawberry root weevils were more resistant to the applied insecticide treatments. Only Topside-treated plots had 90% or greater mortality at 7 DAT, followed by Talstar (60%), Alta (58%), and acephate (54%). Topside-treated plots had 90% or greater mortality at 14 DAT followed by Talstar (76%), Alta (68%), and Closure (60%). Combined root weevil species mortality showed highest mortality at 7 DAT in Topside-treated plots (87% or greater), followed by Alta (74% or greater), and acephate (73%).