Floristic inventory and floristic quality assessment of the LSL tract, Straits of Mackinac, Emmet County, Michigan.

Field Biology of PlantsThe 55 ha Emmet County LSL tract was obtained in 1990 by Emmet County as an addition to their adjacent Cecil Bay Park. The perimeter of the preserve consists of disturbed roadside and a two-track clearing to the north and a power line in the southwest corner. Though the LSL tract is surrounded by paved road and residential properties, the central core of the site remains fairly untouched. The majority of the site consists of a Thuja forest (37 ha) that surrounds relict beach pools and their surrounding marshes (12 ha). Our objective was to conduct a botanical inventory and floristic quality assessment (FQA) of the LSL Tract to establish a baseline of botanical knowledge that may inform future management of the site. We surveyed the property on four separate occasions in June and July of 2013. We collected every new species we encountered within focal habitats. The inventory consisted of 199 species, 165 of which (83%) were native. Coefficients of conservatism and wetness were calculated for every species identified. The entire tract had an FQA of 66.6, the roadsides 24.0, the power line 14.9, the two-track 34.7, the Thuja forest 37.6, and the beach pool marshes 44.1. The majority of the native plants with high conservation value were located in the beach pool marshes. However, two federally threatened, Great Lakes endemic species (Iris lacustris and Solidago houghtonii) were found in the two-track clearing at the northern end of the property. Some invasive species found in the site that may be able to colonize inner parts of the preserve if trails are established. Of these, Cirsium palustre (swamp thistle) and Fallopia japonica (Japanese knotweed) need to be carefully monitored. Here, we provide suggestions for the protection of the valuable native flora of the LSL Tract, a property that is a noteworthy representation of a Straits of Mackinac native forest and wetland complex.http://deepblue.lib.umich.edu/bitstream/2027.42/106397/1/Gingerich_Heyman_Kuesel_Pethan_Steel_2013.pd

The Impact of Plant Essential Oils and Fine Mesh Row Covers on Flea Beetle (Chrysomelidae) Management in Brassicaceous Greens Production

Brassicaceous leafy greens are an important crop for small growers but are difficult to produce due to damage by flea beetles. Flea beetles are problematic for growers as they chew many small holes through leaves rendering produce unmarketable. We tested the efficacy of several essential oils, the woven-mesh row cover ProtekNet, and the spunbonded row cover Agribon, compared to organic and conventional insecticides and no spray controls in the spring and fall of 2019. We found that the two row cover treatments (Agribon and ProtekNet) provided the best control of flea beetles and associated damage. Thyme oil was highly phytotoxic and killed the crop entirely and rosemary and neem essential oils caused mild phytotoxic burns. Organic insecticides rarely performed better than the no spray control. While conventional insecticides controlled most flea beetles, the crop was often still too highly damaged to sell. The results of our study suggest row covers offer producers an effective method of flea beetle control that reduces their dependence on insecticides for conventional and organic production

Pest suppression by ant biodiversity is modified by pest biodiversity

Summary 1. Agroecosystems are often complex ecosystems with diverse food webs. Changes in food web complexity may have important context-dependent consequences for pest control strategies. 2. The success of predator introductions to suppress pests may depend on the diversity of pests. For crops with diverse pest assemblages, it is hypothesized that diverse predator communities are needed to suppress diverse pest assemblages below damaging levels. 3. In this study, we compare the ability of ant predator monocultures and polycultures to suppress single-and diverse-(three species) pest assemblages in a coffee foodweb. We use a factorial experiment that compared treatments of predator and pest diversity to understand the impact of pest diversity on multiple predator effects. 4. We show that predator polycultures enhanced pest risk relative to predator monocultures significantly more in the diverse-pest treatment relative to in the single-pest treatments for two of three pest species. Further, we show that pest diversity significantly reduced pest risk in all predator treatments except for the predator polyculture treatment. 5. These results suggest that pest diversity may reduce the efficiency of single predator species at suppressing pest damage, but do not limit multiple predator species. This in turn leads to stronger effects of predator diversity with greater pest diversity. These results highlight the need to consider foodweb complexity, such as pest diversity, when designing and implementing biology control programs

Landscape Influences and Preventive Management For Drosophila Suzukii In Small Fruit Crops

Small fruit production has been greatly challenged by the repeated invasion of non-native arthropod pests, impacting economic feasibility, and increasing the need for insecticides. Spotted wing drosophila (Drosophila suzukii (Matsumura)) is the most recent invasive pest of small fruits. It causes damage by ovipositing beneath the skin of ripening fruits. Its wide-spread distribution and development of resistance to insecticides has resulted in the need for improved alternative management strategies for small fruit growers. My surveys of D. suzukii at thirteen blackberry (Rubus fruticosus L.) and raspberry (Rubus idaeus L.) fields found that while D. suzukii was present within every fruit sampling locality, traps placed in fruit plantings had higher relative abundance than non-host crop fields and turfgrass fields. Turfgrass fields had lower relative abundance than semi-natural areas and non-host crop fields. Additionally, D. suzukii abundance was correlated with the length of semi-natural habitat edge surrounding farms suggesting a link between this landscape feature and the distribution of D. suzukii in fruit fields. The physical exclusion of insects is beginning to see use as an alternative pest management strategy for small fruits. By physically excluding D. suzukii through the deployment of fine-mesh nets over blackberry rows, I found that fine-mesh exclusions increased marketable yields and reduced D. suzukii captures and larval presence within fruits compared to rows treated with the most efficacious organic insecticide, spinosad. Fall-bearing raspberry production presents challenges to the use of exclusion barriers, as some raspberry cultivars flower asynchronously and repeatedly each season. By establishing fine-mesh exclusions at two phenological timings, I found exclusions applied early in fruit development increased marketable yields and reduced D. suzukii captures and infested fruit weights compared to rows untreated for D. suzukii. Exclusions applied late in fruit development also provided pest control benefits but did not increase marketable yields compared to control rows nor rows treated with organic insecticides. Finally, previous research has also studied the efficacy of fine-mesh exclusions. My review of physical barrier uses in agriculture uncovered twelve publications across cherry (Prunus avium L.), blackberry (Rubus fruticosus L.), blueberry (Vaccinium corymbosum L. and Vaccinium angustifolium Aiton), wine grape (Vitis vinifera L.), and raspberry crops (Rubus idaeus L.). Eleven out of twelve papers found that these barriers are effective at reducing D. suzukii presence and infestation of fruits, while three out of seven papers found that netting can increase the yields of marketable fruits. Throughout this work, I found fine-mesh exclusions can reduce D. suzukii infestation and improve marketable yields in blackberries and raspberries without insecticide usage. In a time where pest management practices are adapting to threats from climate change and invasive species, my work built a body of literature on alternative practices and expanded available IPM strategies

Effects of Fine-Mesh Exclusion Netting on Pests of Blackberry

Fine-mesh exclusion netting is a potential alternative to organic and conventional insecticide application to control numerous pests of fruit crops. We tested whether fine-mesh exclusion netting would reduce pest abundance and increase marketable yield compared to organic spinosad insecticide sprays in an organically managed blackberry field. At the completion of flowering, we covered blackberry rows with fine-mesh exclusion netting (ProtekNet) and treated alternating rows with an organic spinosad insecticide (Entrust™). Fine-mesh exclusion reduced green June beetle (Cotinus nitida Linnaeus) and bird presence and marginally reduced Japanese beetle (Popillia japonica Newman) presence on blackberry canes compared to organic spinosad insecticide treatment. Exclusion netting reduced the capture of spotted-wing Drosophila (Drosophila suzukii Matsumara; “SWD”) in baited traps in the fourth week of exclusion and reduced the overall number of SWD adults emerging from harvested blackberry fruits. Marketable yield in the fine-mesh exclusion treatments was two times higher than the organic spinosad insecticide treatment. These results suggest that fine-mesh exclusion netting is a functional pest control alternative to insecticide treatment for organic blackberry production