Ninety-six species of mites were associated with the southern pine beetle and allied scolytids in an outbreak area in Allen Parish, La. The complex was evaluated to ascertain which species may be of value as biological control agents.

The phenylpropanoid 4-allylanisole is a compound produced by loblolly pines (Pinus taeda L.), an abundant species in southern pine forests and a preferred host of southern pine beetle (Dendroctonus frontalis Zimmermann). Repellency of individual beetles was demonstrated in laboratory behavioral assays ofD. frontalis and other scolytids. Inhibition was demonstrated in natural populations ofD. frontalis using baited traps. In both tests, response to the inhibitory pheromone verbenone was used for comparison. In the laboratory, a higher proportion of newly emerged and reemergedD. frontalis responded negatively to 4-allylanisole than to verbenone. However, fewer reemergent than newly emerged individuals responded to either compound. In all field trials, the response ofD. frontalis to its attractant pheromone in funnel traps was significantly reduced by simultaneous release of 4-allylanisole. In most trials total reduction did not differ from verbenone; however, unlike verbenone, 4-allylanisole reduced male and female catches proportionally. Both compounds together did not significantly further reduce trap catch. The response of a major predator,Thanasimus dubius (F.), to the attractant pheromone ofD. frontalis, did not differ with the simultaneous release of either verbenone or 4-allylanisole. The results of preliminary field applications are presented and discussed.

The importance of visual silhouettes for host finding by the southern pine beetle (SPB), Dendroctonus frontalis (Coleoptera: Scolytidae), and the potential for disruption of this process using visual deterrents were evaluated with multiple‐funnel traps, painted white or black, and with clear, white, or black Plexiglas sticky panels. All traps and panels were baited with the SPB attractant frontalure. The effect of combined semiochemical and visual disruption was evaluated in funnel traps by including the antiaggregation pheromone verbenone, or the repellent/inhibitory host compound 4‐allylanisole, in addition to the attractant. Visual treatments had a highly significant effect on catch of SPB and the predatory clerid beetle Thanasimus dubius. In attractant‐baited traps, white paint alone reduced the average number of SPB caught by 72% in Florida and 68% in Louisiana. The repellent 4‐allylanisole reduced catch of SPB by 56% in Florida and 45% in Louisiana. Verbenone was eluted at 25% of the targeted rate and did not affect total catch in either place. White panels trapped 79% fewer SPB than black, and 55% fewer than clear, with both differences significant. Clear panels also caught significantly fewer (−54%) SPB than black panels. Capture of T. dubius was reduced significantly by clear (−61%) or white (−56%) panels compared to black but did not differ significantly between clear and white panels. The percentage of female SPB captured was not significantly changed by visual treatments but was, as expected, reduced by verbenone. Neither visual nor semiochemical treatments influenced the sex ratio of T. dubius. The potential for using visual disruptants for protection of trees was assessed in front of a single SPB infestation by painting trees either white or black to 4.5 m. White trees showed fewer landings by SPB and a reduced density of successful and total SPB attacks within, but not above, the painted area. These results show that both SPB and T. dubius can be significantly affected by altering visual silhouettes, and that visual and semiochemical treatments, especially used in combination, may increase effectiveness of bark beetle disruption strategies.

Three major species of Ips bark beetles (Coleoptera: Scolytidae) in the southeastern United States, 1. avulsus (Eichoff), 1. calligraphus (Germar), and 1. grandicollis (Eichoff), attack all species of pines in their range, sometimes causing significant tree mortality (Thatcher, 1960 USDA Forest Service Occasional paper 180, 25 pp.) Coincident with region-wide drought, pine mortality due to Ips has been severe throughout the southeastern United States in recent years. For example, losses in 1999 were estimated at about U.S. $13 million dollars, second only to the southern pine beetle in value lost from insect-caused mortality (Report on losses caused by forest insects, Southern Forest Insect Work Conference, 2000). Before effective monitoring, management or research programs can be developed and implemented for Ips beetles in the Southeast, effective lures must be identified for each species. lpsdienol has been identified as an aggregation pheromone for 1.

A simple, small-bolt method was developed and refined for evaluating and screening treatments being considered as prophylactics against bark beetles (Coleoptera: Curculionidae: Scolytinae). Using this method, 4 insecticide products (3 active ingredients) were evaluated against the southern pine beetle, Dendroctonus frontalis Zimmermann, intermittently during a period spanning 1 day to 9 months postapplication. Permethrin (Astro®) showed the best residual effectiveness as determined by the small-bolt assay, followed by bifenthrin (Onyx®) and carbaryl (Ferti-Lome® and Sevin XLR Plus®). Bifenthrin has been reported as effective in field tests with D. frontalis and carbaryl as ineffective, lending credence to the small-bolt method. Results with permethrin suggest that a more extensive evaluation may be warranted for this active ingredient. The method as developed provides a useful and efficient tool for Identifying preventive treat-ments that are unlikely to be effective against D. frontalis. Its use for screening ineffective products would limit expensive and time-consuming field evaluations to treatments that show significant promise. With additional refinement, the small-bolt assay may provide most of the benefits of more costly testing methods while offering sufficient flexibility for comparing prophylactic treatments that rely on different modes of action.