@article{ranger_parajuli_gresham_barnett_villani_walgenbach_baysal-gurel_owen jr_reding_2023, title={Type and duration of water stress influence host selection and colonization by exotic ambrosia beetles (Coleoptera: Curculionidae)}, volume={3}, ISSN={["2673-8600"]}, DOI={10.3389/finsc.2023.1219951}, abstractNote={Fungus-farming ambrosia beetles in the tribe Xyleborini tunnel into plants and trees to establish chambers for cultivating their nutritional fungal mutualists and rearing offspring. Some xyleborine ambrosia beetles preferentially infest and perform better in living but weakened trees. Flood stress predisposes horticultural tree crops to infestation, but the impact of drought stress has not been well studied. Our objectives were to compare the effects of flood stress vs. drought stress on host selection and colonization by xyleborine ambrosia beetles and to assess the duration of flooding. Container-grown Cornus florida L. trees were flood stressed using a pot-in-pot system to submerge the roots in water while drought-stressed conditions were imposed by withholding irrigation and precipitation. When experimental trees were held under field conditions for 14 days, 7.5 × more ambrosia beetles landed on stems of the flood-stressed than on the drought-stressed trees. During two additional experiments over 14 and 22 days, ambrosia beetles tunneled into the flood-stressed trees but not the drought-stressed or standard irrigation trees. By simultaneously deploying trees that were flood stressed for varying lengths of time, it was found that more tunnel entrances, and xyleborine adults and offspring were recovered from trees that were flooded for 1–16 days and 7–22 days than from trees that were flooded for 14–29 days and 28–43 days. These results indicate that acute and severe drought stress does not predispose C. florida to infestation, but flood stress and the duration of flooding influence ambrosia beetle host selection and colonization. Understanding the role of host quality on ambrosia beetle preference behavior will assist with predicting the risk of infestation of these opportunistic insects in horticultural tree crops.}, journal={FRONTIERS IN INSECT SCIENCE}, author={Ranger, Christopher M. and Parajuli, Madhav and Gresham, Sean and Barnett, Jenny and Villani, Sara and Walgenbach, James and Baysal-Gurel, Fulya and Owen Jr, James S. and Reding, Michael E.}, year={2023}, month={Jul} }
 @article{strickland_villani_cox_2022, title={Optimizing Use of DMI Fungicides for Management of Apple Powdery Mildew Caused by Podosphaera leucotricha in New York State}, volume={106}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-09-21-2025-RE}, abstractNote={ Powdery mildew, caused by the ascomycete Podosphaera leucotricha, is an endemic disease found wherever apples are grown that reduces both tree vigor and fresh market yield. In the absence of durable host resistance, chemical management is the primary means of disease control. Demethylation inhibitor (DMI) fungicides are widely used to manage apple powdery mildew, but members within this fungicide class have been observed to differ in efficacy with respect to disease control. Moreover, debate exists as to the optimal timing of DMI fungicide applications for management of apple powdery mildew. In this regard, the goal of this study was to determine the best-use practices for DMI fungicides to manage apple powdery mildew in New York State. Multiyear trials were conducted to evaluate the potential differential efficacy performance of four common DMI fungicides, and additional trials were conducted to assess optimal application timing. In all years, we observed that treatments of flutriafol and myclobutanil consistently had the lowest incidences of powdery mildew compared with difenoconazole and fenbuconazole. In the 2018 and 2021 trials, the newly registered mefentrifluconazole was more comparable to the difenoconazole program with respect to powdery mildew disease incidence. We hypothesize that differences in DMI efficacy may result from each fungicide’s water solubility and lipophilicity characteristics and thus their ability to move systemically in the host or more easily penetrate the surface of germinating conidia. Applications timed between petal fall and first cover resulted in the lowest incidence of powdery mildew on terminal leaves of apple shoots compared with applications timed before petal fall. These observations are contrary to previous studies conducted in regions with differing climates. We also found that the incidence of secondary powdery mildew observed 2 weeks after petal fall was influenced by applications of DMI fungicides during the previous season. For example, management programs consisting of applications of flutriafol or myclobutanil in the previous season tended to have lower incidence of apple powdery in the next spring, presumably because of reductions in overwintering inoculum. Despite reports of DMI resistance in other apple pathosystems, the DMI fungicide class is still relevant for the successful management of apple powdery mildew in New York State. }, number={4}, journal={PLANT DISEASE}, author={Strickland, David A. and Villani, Sara M. and Cox, Kerik D.}, year={2022}, month={Apr}, pages={1226–1237} }
 @article{lichtner_jurick_ayer_gaskins_villani_cox_2020, title={A Genome Resource for Several North American Venturia inaequalis Isolates with Multiple Fungicide Resistance Phenotypes}, volume={110}, ISSN={["1943-7684"]}, DOI={10.1094/PHYTO-06-19-0222-A}, abstractNote={ The apple scab pathogen, Venturia inaequalis, is among the most economically important fungal pathogens that affects apples. Fungicide applications are an essential part of disease management. Implementation of cultural practices and genetic sources of resistance in the host are vital components of scab management. This is the first presentation of multiple, high quality, well-annotated genomes of four North American V. inaequalis isolates having both sensitive and multiple fungicide resistance phenotypes. We envision that these isolates will enable investigations into fungicide resistance mechanisms, exploring fungal virulence factors and delineating phylogenomic relationships among apple scab isolates from around the world. }, number={3}, journal={PHYTOPATHOLOGY}, author={Lichtner, Franz J. and Jurick, Wayne M., II and Ayer, Katrin M. and Gaskins, Verneta L. and Villani, Sara M. and Cox, Kerik D.}, year={2020}, month={Mar}, pages={544–546} }
 @article{cha_hesler_brind'amour_wentworth_villani_cox_boucher_wallingford_park_nyrop_et al._2020, title={Behavioral evidence for contextual olfactory-mediated avoidance of the ubiquitous phytopathogen Botrytis cinerea by Drosophila suzukii}, volume={27}, ISSN={["1744-7917"]}, DOI={10.1111/1744-7917.12691}, abstractNote={Abstract}, number={4}, journal={INSECT SCIENCE}, author={Cha, Dong H. and Hesler, Stephen P. and Brind'Amour, Gabrielle and Wentworth, Karen S. and Villani, Sara and Cox, Kerik D. and Boucher, Matthew T. and Wallingford, Anna and Park, Shinyoung K. and Nyrop, Jan and et al.}, year={2020}, month={Aug}, pages={771–779} }
 @article{dowling_peres_villani_schnabel_2020, title={Managing Colletotrichum on Fruit Crops: A "Complex" Challenge}, volume={104}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-11-19-2378-FE}, abstractNote={ The fungal genus Colletotrichum includes numerous important plant pathogenic species and species complexes that infect a wide variety of hosts. Its taxonomy is particularly complex because species’ phenotypes and genotypes are difficult to differentiate. Two notable complexes, C. acutatum and C. gloeosporioides, are known for infecting temperate fruit crops worldwide. Even species within these complexes vary in traits such as tissue specificity, aggressiveness, geographic distribution, and fungicide sensitivity. With few effective chemicals available to control these pathogens, and the persistent threat of fungicide resistance, there is a need for greater understanding of this destructive genus and the methods that can be used for disease management. This review summarizes current research on diseases caused by Colletotrichum spp. on major fruit crops in the United States, focusing on the taxonomy of species involved, disease management strategies, and future management outlook. }, number={9}, journal={PLANT DISEASE}, author={Dowling, Madeline and Peres, Natalia and Villani, Sara and Schnabel, Guido}, year={2020}, month={Sep}, pages={2301–2316} }
 @article{ayer_villani_choi_cox_2019, title={Characterization of the VisdhC and VisdhD Genes in Venturia inaequalis, and Sensitivity to Fluxapyroxad, Pydiflumetofen, Inpyrfluxam, and Benzovindiflupyr}, volume={103}, ISSN={["1943-7692"]}, DOI={10.1094/PDIS-07-18-1225-RE}, abstractNote={ Succinate dehydrogenase inhibitors (SDHI) are an important class of fungicides for management of apple scab, especially as resistance to other classes of fungicides has become prevalent in the northeastern United States. Considering their single-site mode of action, there is high risk of resistance development to SDHI fungicides. Such risk mandates the need for proper monitoring of shifts in population sensitivity. This study aims to provide a means for phenotypic and genotypic characterization of SDHI fungicide resistance for Venturia inaequalis, the causal agent of apple scab. To complement the published sequence of VisdhB, target genes VisdhC and VisdhD were identified using sequences of homologous genes in other fungal organisms and a draft genome of V. inaequalis. Using mycelial growth and conidial germination assays, baseline sensitivities and cross sensitivities of V. inaequalis were determined for several SDHI fungicides. Mean baseline EC50 values for conidial germination of benzovindiflupyr, fluxapyroxad, pydiflumetofen, and inpyrfluxam were found to be 0.0021, 0.0284, 0.014, and 0.0137 μg ml−1, respectively. Mean baseline EC50 values for mycelial growth of benzovindiflupyr, fluxapyroxad, pydiflumetofen, and inpyrfluxam were found to be 0.0575, 0.228, 0.062, and 0.0291 μg ml−1, respectively. A significant and positive correlation in sensitivity was found between benzovindiflupyr, fluxapyroxad, pydiflumetofen, and inpyrfluxam as well as penthiopyrad and fluopyram, with the highest correlation between benzovindiflupyr and penthiopyrad for mycelial inhibition of V. inaequalis (r = 0.950, P < 0.001). For inhibition of conidial germination, the highest correlation was observed between penthiopyrad and fluopyram (r = 0.775, P < 0.001). Furthermore, the sequences of the VisdhC and VisdhD genes were identified and characterized for baseline isolates of V. inaequalis. Residues of similar position to mutations found in other systems that confer resistance to SDHI fungicides were identified in baseline isolates, but no mutations were identified in baseline isolates or those previously exposed to SDHI fungicides. This study will serve as a reference for future monitoring of resistance to SDHI fungicides in V. inaequalis at both a phenotypic and genotypic level. }, number={6}, journal={PLANT DISEASE}, author={Ayer, Katrin M. and Villani, Sara M. and Choi, Mei-Wah and Cox, Kerik D.}, year={2019}, month={Jun}, pages={1092–1100} }
 @article{villani_cox_sundin_2019, title={Optimizing disease management in fruit cultivation}, volume={53}, ISBN={["978-1-78676-208-5"]}, ISSN={["2059-6944"]}, DOI={10.19103/AS.2018.0040.12}, journal={ACHIEVING SUSTAINABLE CULTIVATION OF TEMPERATE ZONE TREE FRUITS AND BERRIES, VOL 1: PHYSIOLOGY, GENETICS AND CULTIVATION}, author={Villani, Sara M. and Cox, Kerik D. and Sundin, George W.}, year={2019}, pages={401–431} }
 @article{villani_ayer_cox_2016, title={Molecular Characterization of the sdhB Gene and Baseline Sensitivity to Penthiopyrad, Fluopyram, and Benzovindiflupyr in Venturia inaequalis}, volume={100}, ISSN={["1943-7692"]}, DOI={10.1094/pdis-12-15-1512-re}, abstractNote={ The succinate dehydrogenase inhibiting (SDHI) fungicides are a class of single-site fungicides that are increasingly important in the management of Venturia inaequalis. In this study, the baseline sensitivity of V. inaequalis to penthiopyrad, fluopyram, and benzovindiflupyr was investigated. In all, 35 to 70 isolates with no prior exposure to single-site fungicides were used to determine the effective concentration at which growth was inhibited by 50% (EC50). Mean EC50 values for the conidial germ tube growth stage for penthiopyrad, fluopyram, and benzovindiflupyr were 0.086, 0.176, and 0.0016 μg ml−1, respectively. Linear correlation analysis revealed a significant and positive correlation between fluopyram and penthiopyrad (P ≤ 0.0001, r = 0.66) and fluopyram and benzovindiflupyr (P = 0.0014, r = 0.52). Baseline sensitivities of V. inaequalis during the mycelial growth stage were also determined for fluopyram and benzovindiflupyr. EC50 values were higher for fluopyram and benzovindiflupyr during this stage compared with the conidial germ tube growth stage, with means of 0.043 and 2.02 μg ml−1, respectively. In addition, the sdhB gene was characterized for three isolates of V. inaequalis collected from a research, baseline, and commercial orchard population. No common mutation sites associated with SDHI resistance in other phytopathogenic fungi were discovered in these isolates or isolates that were recovered following field applications of SDHI fungicides. The results of this study suggest that SDHI fungicides have a high level of activity during the conidial germ tube elongation stage in V. inaequalis and provide a basis for phenotypic and genotypic monitoring of shifts toward resistance of V. inaequalis populations to the SDHI fungicide class. }, number={8}, journal={PLANT DISEASE}, author={Villani, Sara M. and Ayer, Katrin and Cox, Kerik D.}, year={2016}, month={Aug}, pages={1709–1716} }
 @article{villani_hulvey_hily_cox_2016, title={Overexpression of the CYP51A1 Gene and Repeated Elements are Associated with Differential Sensitivity to DMI Fungicides in Venturia inaequalis}, volume={106}, ISSN={["1943-7684"]}, DOI={10.1094/phyto-10-15-0254-r}, abstractNote={ The involvement of overexpression of the CYP51A1 gene in Venturia inaequalis was investigated for isolates exhibiting differential sensitivity to the triazole demethylation inhibitor (DMI) fungicides myclobutanil and difenoconazole. Relative expression (RE) of the CYP51A1 gene was significantly greater (P < 0.0001) for isolates with resistance to both fungicides (MRDR phenotype) or with resistance to difenoconazole only (MSDR phenotype) compared with isolates that were resistant only to myclobutanil (MRDS phenotype) or sensitive to both fungicides (MSDS phenotype). An average of 9- and 13-fold increases in CYP51A1 RE were observed in isolates resistant to difenoconazole compared with isolates with MRDS and MSDS phenotypes, respectively. Linear regression analysis between isolate relative growth on myclobutanil-amended medium and log10 RE revealed that little to no variability in sensitivity to myclobutanil could be explained by CYP51A1 overexpression (R2 = 0.078). To investigate CYP51A1 upstream anomalies associated with CYP51A1 overexpression or resistance to difenoconazole, Illumina sequencing was conducted for three isolates with resistance to difenoconazole and one baseline isolate. A repeated element, “EL 3,1,2”, with the properties of a transcriptional enhancer was identified two to four times upstream of CYP51A1 in difenoconazole-resistant isolates but was not found in isolates with the MRDS phenotype. These results suggest that different mechanisms may govern resistance to different DMI fungicides in the triazole group. }, number={6}, journal={PHYTOPATHOLOGY}, author={Villani, Sara M. and Hulvey, Jon and Hily, Jean-Michel and Cox, Kerik D.}, year={2016}, month={Jun}, pages={562–571} }