Cheryl Frank Sullivan

Bio: Cheryl Frank Sullivan is an academic researcher from University of Vermont. The author has contributed to research in topics: Metarhizium anisopliae & Metarhizium brunneum. The author has an hindex of 1, co-authored 4 publications receiving 4 citations.

Evaluation of spray applications of Metarhizium anisopliae, Metarhizium brunneum and Beauveria bassiana against larval winter ticks, Dermacentor albipictus

Abstract: Dermacentor albipictus (Acari: Ixodidae), the winter tick, is a one-host tick that parasitizes large ungulates. They can dramatically affect moose, Alces alces (Artiodactyla: Cervidae), causing significant physiological and metabolic stress and mortality among heavily parasitized individuals. Entomopathogenic fungi in the genera Metarhizium (Hypocreales: Clavicipitaceae) and Beauveria (Hypocreales: Cordycipitaceae) are promising tick biological control agents. We examined the pathogenicity of experimental and commercially formulated isolates of M. anisopliae, M. brunneum and B. bassiana sprayed at concentrations of 106, 107 and 108 conidia/mL against the larval stage of D. albipictus and assessed the efficacy of spraying the commercial product Met52®EC, containing M. brunneum, strain F52, under laboratory conditions. Results showed larval D. albipictus mortality was significantly higher and occurred earlier when treated with M. anisopliae and M. brunneum isolates compared to B. bassiana at 106, 107 and 108 conidia/mL. Mortality was observed as early as 3 days in the M. anisopliae and M. brunneum treatments and after 6 days in the B. bassiana treatments. After 21 days, larval mortality ranged from 74–99% when ticks were treated with M. anisopliae and M. brunneum isolates at 106, 107 and 108 and conidia/mL. In contrast, mortality of ticks treated with B. bassiana ranged from 30 to 64%. When larvae were treated with the commercial product Met52, mortality was ~ 45% after 3 days and ~ 96% after 9 days. These results demonstrate the effectiveness of M. anisopliae and M. brunneum against D. albipictus.

Effectiveness of granular formulations of Metarhizium anisopliae and Metarhizium brunneum (Hypocreales: Clavicipitaceae) on off-host larvae of Dermacentor albipictus (Acari: Ixodidae)

Abstract: There is a critical need to develop effective, high-quality, fungal-based biopesticides for use against ticks. Dermacentor albipictus, the winter tick, is a one-host species that can cause mortalit...

Biological control of Western flower thrips, Frankliniella occidentalis using a self-sustaining granular fungal treatment.

Abstract: Western flower thrips (WFT), Frankliniella occidentalis, is one of the most destructive pests of vegetables, fruits and ornamental crops worldwide, causing extensive damage by direct feeding of the crop and transmitting economically important viruses. Despite the successes of biocontrol agents to control WFT, more efficient and cost-effective ways must be found to encourage grower adoption of integrated pest management. A sustainable fungal treatment was developed to preserve fungal inoculum in potting soil and reduce thrips populations. Combining cooked, oven-dried millet with BotaniGard® (a commercial form of Beauveria bassiana strain GHA) to potting soil increased spore production and persistence of the fungus in the soil. In treated pots with millet, spore concentrations were 3-4 times greater after 30 days compared with spore yields at 10 days. The number of WFT adults was significantly lower in the marigold pots treated with GHA mix + millet than untreated controls, 12% and 10% in treated pots and 70% and 68% in untreated pots in sterile and non-sterile soil, respectively. Incorporation of millet in the potting mix enhanced the effect of the fungal treatments by providing a nutritive substrate on which the fungus could become established. This method is relatively inexpensive and easy for growers to use in greenhouses because granular formulations of B. bassiana are not commercially available.

Survival of off-host Dermacentor albipictus (Acari: Ixodidae) adult females and larvae underwater

Abstract: Dermacentor albipictus (Packard, 1869) [Acari: Ixodidae], the winter tick, significantly affects the health and productivity of North American moose (Alces alces (Linnaeus, 1758) [Artiodactyla: Cervidae]). Survival of off-host stages of Ixodid ticks depends on microclimate driven in part by extrinsic factors resulting from weather, such as temperature, humidity, drought, and floods. The impact of some of these abiotic factors is unclear for D. albipictus. The effect of water submergence on biological parameters of engorged, adult, females and unfed larvae was assessed in the laboratory. Survival of adult females after submergence for three days was 88% with significant effects on their ability to oviposit. After five weeks, 63% of larvae (one-month-old) survived submergence in water whereas survival of larvae (three-months-old) was reduced to 23% after seven days. The off-host stages of D. albipictus have variable tolerance to periods of submergence that may influence the number of larvae available on the landscape for recruitment to moose in autumn.

A Review of Commercial Metarhizium- and Beauveria-Based Biopesticides for the Biological Control of Ticks in the USA

Abstract: Simple Summary Microbial biopesticides containing entomopathogenic fungi have potential in tick management. In this review, we compiled a comprehensive list of the use of commercialized Metarhizium and Beauveria-based biopesticides in the USA that have been tested against ixodid ticks under laboratory and field conditions and when used as a part of integrated tick management. Despite considerable progress in the development of fungal biopesticides over the past 20 years, the establishment of commercial products available for use against ticks continues to be slow. There is a need for the development of sustainable, nonchemical tick management strategies. Until efficacious fungus-based products become more available, tick management will rely primarily on synthetic chemical acaricides, with natural-product acaricides as the alternative. Abstract There is a need for the development of sustainable, nonchemical tick management strategies. Mycoacaricide and mycoinsecticide product development worldwide has focused primarily on fungi in the genera Beauveria (Hypocreales: Cordycipitaceae) and Metarhizium (Hypocreales: Clavicipitaceae). Microbial biopesticides containing entomopathogenic fungi have potential in tick management. However, despite considerable progress in the development of fungal biopesticides over the past 20 years, the establishment of commercial products available for use against ticks continues to be slow. We reviewed published scientific literature and compiled a comprehensive list of reports of the effectiveness of commercial biopesticides based on the fungal genera Metarhizium and Beauveria and registered for use in the USA against ixodid ticks under laboratory and field conditions. We also report on results when these biopesticides were used as a part of integrated tick management. Until efficacious fungus-based products become more available, tick management will rely primarily on synthetic chemical acaricides, with natural-product acaricides as the alternative.

Entomopathogenic Fungi and Bacteria in a Veterinary Perspective

Abstract: The present study aimed to review the papers dealing with the biological activity of fungi and bacteria against some mites and ticks of veterinary interest. In particular, the attention was turned to the research regarding acarid species, Dermanyssus gallinae and Psoroptes sp., which are the cause of severe threat in farm animals and, regarding ticks, also pets. Their impact on animal and human health has been stressed, examining the weaknesses and strengths of conventional treatments. Bacillus thuringiensis, Beauveria bassiana and Metarhizium anisopliae are the most widely employed agents. Their activities have been reviewed, considering the feasibility of an in-field application and the effectiveness of the administration alone or combined with conventional and alternative drugs is reported.

Moose Habitat Selection and Fitness Consequences During Two Critical Winter Tick Life Stages in Vermont, United States†

Abstract: The moose (Alces alces) is a charismatic species in decline across much of their southern distribution in North America. In the northeastern United States, much of the reduction has been attributed to winter tick (Dermacentor albipictus) infestations. Winter ticks are fairly immobile throughout all life stages, and therefore their distribution patterns at any given time are shaped largely by the occurrence of moose across the landscape during the peak of two critical time periods: fall questing (when ticks latch onto moose) and spring drop-off (when engorged female ticks detach from moose). We used recent land cover and lidar data within a dynamic occupancy modeling framework to estimate first-order habitat selection (use vs non-use) of female moose (n = 74) during the tick questing and drop-off periods. Patch extinction and colonization rates during spring drop-off periods were strongly influenced by habitat and elevation, but these effects were diminished during the fall questing period when moose were more active across the landscape. From the fall questing period to the spring drop-off period, patches where colonization was high and extinction low had higher proportions of young (shrub/forage) mixed forest at higher elevations. Further, we evaluated the fitness consequences of habitat selection by adult females during the fall questing period, when females and their calves acquire ticks. We compared Resource Selection Functions (RSF) for 5 females that successfully reared a calf to age 1 with 5 females whose calves perished due to ticks. Adult female moose whose offspring perished selected habitats in the fall that spatially coincided with areas of high occupancy probability during the spring tick drop-off period. In contrast, adult female moose whose offspring survived selected areas where the probability of occupancy during the spring drop-off was low; at present, natural selection may favor female adults who do not select the same habitats in fall as in spring. Our model coefficients and mapped results define “hotspots” that are likely encouraging the deleterious effects of the tick-moose cycle. These findings fill knowledge gaps about moose habitat selection that may improve the effectiveness of management aimed at reversing declining population trends.

Effectiveness of granular formulations of Metarhizium anisopliae and Metarhizium brunneum (Hypocreales: Clavicipitaceae) on off-host larvae of Dermacentor albipictus (Acari: Ixodidae)

Abstract: There is a critical need to develop effective, high-quality, fungal-based biopesticides for use against ticks. Dermacentor albipictus, the winter tick, is a one-host species that can cause mortalit...