Cell and tissue structure of undamaged soybean, Glycine max (L.) Merrill, stems were compared with those from the swollen area immediately above (< 1 cm) threecornered alfalfa hopper, Spissistilus festinus (Say), girdles. Examination of epoxy - resin embedded transverse sections from the swollen stems revealed growth that differed significantly from the normal dicot structure. The anomalous growth consisted of vascular bundles scattered in the secondary phloem surrounded by parenchyma cells. Examination of Paraplast® embedded transverse and longitudinal sections of adventitious root - like growths arising from or above the swollen hypocotyl area revealed normal root structure.

T he bacterium Mycoplasma bovis is an economically important pathogen of cattle that contributes to the multifactorial bovine respiratory disease complex. In addition to causing respiratory disease, this bacterium can cause polyarthritis, mastitis, otitis media, and a chronic pneumonia-polyarthritis syndrome, impacting beef and dairy cattle worldwide (1). Despite increased recognition of its role in economic loss in the cattle industry, M. bovis remains a clinical challenge because of a common carrier state in clinically healthy animals, variable disease expression, intermittent shedding, and the lack of rapid accurate diagnostic assays (1,2). Clinical disease is not considered necessary to maintain M. bovis in populations, and M. bovis is commonly detected in asymptomatic adult feedlot cattle (2). Although the upper respiratory tract mucosa is a primary site for M. bovis colonization, presence of the bacterium in the lung is variable in occurrence and clinical manifestation. In 1 study, M. bovis was detected in 46% of cattle with normal lungs, 82% of cattle with acute fibrinous pneumonia, and 98% of cattle with chronic pneumonia (3). Manifestation of M. bovis-associated respiratory disease is particularly common in the wake of stress (e.g., from transportation, comingling, feedlot entry, and harsh temperatures or conditions). In the early 2000s, M. bovis caused several highmortality (case-fatality rate 45%) epizootics in bison (Bison bison) in North America (4). These events raised concern about emergent virulent strains, and research began to characterize isolates from different host species (5). An important difference between outbreaks of mycoplasmosis in bison and cattle is that, in the former, few or no co-infecting bacterial or viral pathogens are consistently detected (4,6-8). Although M. bovis virulence factors are poorly defined, evasion of immune response is implicated in maintaining chronic infection (9). One study found that that up to 79% of bison herds in western Canada have >1 M. bovis-seropositive animal and that 8 of 11 herds with no history of M. bovis disease had seropositive animals (10). These findings suggest that host response to M. bovis varies; some exposed bison become subclinical carriers and might also

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Mycoplasma bovis is an economically important bacterial pathogen of cattle and bison that most commonly causes pneumonia, polyarthritis and mastitis. M. bovis is prevalent in cattle and commercial bison; however, infections in other species are rare. In early 2019, we identified M. bovis in free-ranging pronghorn (Antilocapra americana) in northeastern Wyoming, USA. Here we report on additional pronghorn mortalities caused by M. bovis occurring in the same ~120 km 2 geographic region one year later. Genetic analysis by multilocus sequence typing (MLST) revealed that the mortalities were caused by the same M. bovis sequence type, which is unique among all sequence types documented thus far in North America. To explore whether pronghorn maintain chronic infections and begin assessing M. bovis status in other sympatric species, we used PCR testing of nasal swabs to opportunistically survey select free-ranging ungulates. We found no evidence of subclinical infections in 13 pronghorn sampled from the outbreak area (upper 95% binomial confidence limit [bCL] ~24.7%) or among 217 additional pronghorn (upper 95% bCL ~1.7%) sampled from eight additional counties in Wyoming and ten in Montana, USA. All mule deer (Odocoileus hemionus) (n=231; upper 95% bCL ~1.6%) sampled from 11 counties in Wyoming also were PCR negative. To assess the potential for environmental transmission, we examined persistence of M. bovis in various substrates and conditions. Controlled experiments revealed that M. bovis can remain viable for 6 hours following inoculation of shaded water, and for up to 3 hours in direct sunlight. Our results indicate that environmental transmission of M. bovis from livestock to pronghorn is possible, and that seasonality of infection could be due to shared resources during late winter. Further investigations to better understand transmission dynamics, to assess population level impacts to pronghorn, and to determine disease risks among pronghorn and other ungulate taxa appear warranted. Johnson et al. Source and seasonality of mycoplasmosis in pronghorn

Hypocotyls of vegetative V1 and V3 stage soybean, Glycine max (L.) Merrill were subjected to feeding by third, fourth, and fifth instars of the threecornered alfalfa hopper, Spissistilus festinus (Say). Significant differences in feeding injury, plant responses, fresh and dry root weights, and plant stage development occurred due to fourth instar feeding on V1 stage plants. Most soybean plants responded to partial and complete girdles by producing swelling and/or adventitious roots above the girdle.