Use of Semiochemicals for the Management of the Redbay Ambrosia Beetle.

This review highlights current advances in the management of the redbay ambrosia beetle, Xyleborus glabratus, a primary vector of the pathogenic fungus, Raffaelea lauricola, that causes laurel wilt. Laurel wilt has a detrimental effect on forest ecosystems of southeastern USA, with hundreds of millions of Lauraceae deaths. Currently, preventive measures mostly focus on infected-tree removal to potentially reduce local beetle populations and/or use of preventative fungicide applications in urban trees. Use of semiochemicals may offer an opportunity for the management of X. glabratus. Research on attractants has led to the development of α-copaene lures that are now the accepted standards for X. glabratus sampling. Research conducted on repellents first included methyl salicylate and verbenone and attained significant reduction in the number of X. glabratus captured on redbay and swamp bay trees treated with verbenone. However, the death rate of trees protected with verbenone, while lower compared to untreated trees, is still high. This work underscores the necessity of developing new control methods, including the integration of repellents and attractants into a single push-pull system.

Evaluation of semiochemical based push-pull strategy for population suppression of ambrosia beetle vectors of laurel wilt disease in avocado.

Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) bore into tree xylem to complete their life cycle, feeding on symbiotic fungi. Ambrosia beetles are a threat to avocado where they have been found to vector a symbiotic fungus, Raffaelea lauricola, the causal agent of the laurel wilt disease. We assessed the repellency of methyl salicylate and verbenone to two putative laurel wilt vectors in avocado, Xyleborus volvulus (Fabricius) and Xyleborus bispinatus (Eichhoff), under laboratory conditions. Then, we tested the same two chemicals released from SPLAT flowable matrix with and without low-dose ethanol dispensers for manipulation of ambrosia beetle populations occurring in commercial avocado. The potential active space of repellents was assessed by quantifying beetle catch on traps placed 'close' (~5-10 cm) and 'far' (~1-1.5 m) away from repellent dispensers. Ambrosia beetles collected on traps associated with all in-field treatments were identified to species to assess beetle diversity and community variation. Xyleborus volvulus was not repelled by methyl salicylate (MeSA) or verbenone in laboratory assays, while X. bispinatus was repelled by MeSA but not verbenone. Ambrosia beetle trap catches were reduced in the field more when plots were treated with verbenone dispensers (SPLAT) co-deployed with low-dose ethanol dispensers than when treated with verbenone alone. Beetle diversity was highest on traps deployed with low-dose ethanol lures. The repellent treatments and ethanol lures significantly altered the species composition of beetles captured in experiment plots. Our results indicate that verbenone co-deployed with ethanol lures holds potential for manipulating ambrosia beetle vectors via push-pull management in avocado. This tactic could discourage immigration and/or population establishment of ambrosia beetles in commercial avocado and function as an additional tool for management programs of laurel wilt.

Phenology, Distribution, and Diversity of Dung Beetles (Coleoptera: Scarabaeidae) in North Florida's Pastures and Forests.

Dung beetles are important to ecosystems as they aid in nutrient recycling and waste removal. In North Florida, there is a high diversity of dung beetles due to the intentional and accidental introduction of non-native species. Understanding patterns and processes on local scales is important for conservational planning. The aim of this study was to evaluate how dung beetle communities respond to different dung sources, forage composition, and habitat types. We surveyed for the presence and distribution of dung beetles in an open field and forest as well as in three types of pasture forage designs. In the first experiment, four transects with pitfall traps from forest to open field were established with either horse, pig, or cow feces bait. In the second experiment, three cattle grazing systems with different forage species were tested with only cow feces. In the first experiment, 16 species were identified between the field and forest sites including native and exotic species. Although the dung type had little effect on beetle distribution, a significantly different distribution of dung beetles between the field and forest was observed. Only one species, Onthophagus hecate Panzer (Coleoptera: Scarabaeidae) showed no preference between open field and forest habitat. During this second experiment, no difference in dung beetle distribution was found between the three types of pasture assemblages. This study supports habitat type as a driver of interspecies distribution and diversity of dung beetles in North Florida.

Evaluation of Three Commercial Backpack Sprayers with Aqualuer® 20-20 Against Caged Adult Aedes Aegypti.

Three commercially available backpack sprayers were evaluated with Aqualuer® 20-20 (20.6% permethrin, active ingredient; 20.6% piperonyl butoxide, technical) against caged adult Aedes aegypti in semifield trials in northeastern Florida. Two battery-powered sprayers, Birchmeier and Hudson, were compared with the standard hand-pump SOLO 425 sprayer, which is currently used in pest management operations. Physical characteristics, droplet analysis, and overall ease of use were documented. Multiple dilutions of the insecticide were also evaluated. The results indicated that the Birchmeier sprayer was the preferable machine in terms of its physical characteristics and operator use. There was no significant difference in percent mortality of the test mosquitoes between the sprayers. Multiple dilutions ranging from 1:9 to 1:1050 of the insecticide resulted in greater than 80% mean mortality.