A phenotypic characterization of Rarámuri Criollo cattle introduced into the Southwestern United States

Our objective was to describe key phenotypic characteristics of a population of Rarámuri Criollo (RC) cattle introduced from the Copper Canyon of Chihuahua, México into the Southwestern United States almost two decades ago. We recorded 26 phenotypic traits of 37 RC individuals including mature cows, first-calf heifers, and mature bulls raised at the USDA-ARS Jornada Experimental Range in southern New Mexico. This herd of RC cattle exhibited intermediate body sizes compared to the smaller Corriente and larger Texas Longhorn and Florida Cracker cattle. Coat colors were similar to those described for other Criollo biotypes but horn shape and size of RC appear to be different than that of other US-based Criollo breeds. Though smaller than commercial beef breeds, RC cattle appear to be well-matched to the Southwestern US environments as evidenced by previous studies that evaluated their grazing behavior, weight gains, and carcass quality. Rarámuri Criollo cattle are a genetic resource whose conservation could be critically important for climate change adaptation of ranches in the desert Southwest.

Post-fire early successional vegetation buffers surface microclimate and increases survival of planted conifer seedlings in the Southwestern United States

Climate change and fire-exclusion have increased the flammability of western United States forests, leading to forest cover loss when wildfires occur under severe weather conditions. Increasingly large high-severity burn patches limit natural regeneration because of dispersal distance, increasing the chance of conversion to non-forest. Post-fire planting can overcome dispersal limitations, yet warmer and drier post-fire conditions can still reduce survival. We examined how two shrub species with different structures affect below-shrub microclimate and survival rates of planted tree seedlings (Pinus ponderosa, P. edulis, P. strobiformis, Pseudotsuga menziesii) following a high-severity fire in northern New Mexico. We expected that Gambel oak (Querus gambelii), with its denser canopy, would buffer below-shrub climate causing higher survival rates of planted seedlings more than the lower canopy density New Mexico locust (Robinia neomexicana). Seedlings planted under Gambel oak had survival rates 10% to 35% greater than those planted under New Mexico locust. Higher light availability beneath New Mexico locust corresponded to higher temperatures, lower humidity, and higher vapor pressure deficit, impacting the mortality of planted tree seedlings. These results indicate that by waiting for post-fire shrub establishment, selective use of shrubs can buffer microclimate and increase post-fire planting success in the southwestern United States.

Disseminated Coccidioidomycosis Presenting as Fever of Unknown Origin and Erythema Nodosum in a 3-Year-Old Child

Disseminated coccidioidomycosis is a disease caused by Coccidioides species, fungi endemic to the southwestern United States. We present here an uncommon case of a young child with erythema nodosum and fever of unknown origin, found to have the infection. While more common in adults, coccidioidomycosis should be considered in all patients with erythema nodosum.

Rattlesnake envenomation in 2 Visayan warty pigs

Rattlesnake envenomation is an important cause of morbidity and mortality in humans and animals in the southwestern United States and elsewhere. Two Visayan warty pigs ( Sus cebifrons) from a regional zoo were submitted for autopsy after being found dead close to a southern Pacific rattlesnake ( Crotalus helleri) in their enclosure. Both pigs had severe regionally extensive cutaneous, subcutaneous, and muscle hemorrhage and edema with myonecrosis. Additionally, both pigs had lesions consistent with puncture wounds within the oral cavity, and one pig had a similar wound on a forelimb. The history, and gross and histologic findings, were consistent with envenomation by rattlesnake bite. There are few documented cases of snakebite envenomation in pigs, and it had been suggested that pigs may have some degree of resistance to envenomation. Our results indicate that warty pigs are susceptible to the action of rattlesnake venom.

A Southwestern United States Pilot Investigation of Triatomine–Mite Prevalence

Background: Chagas disease is a leading cause of cardiac failure in Latin America. Due to poor safety profiles and efficacy of currently available therapeutics, prevention is a priority for the millions living at risk for acquiring this clinically important vector-borne disease. Triatomine vectors of the Chagas disease parasite, Trypanosoma cruzi, are found in the southwestern United States, but risk for autochthonous transmission is thought to be low. The role of ectoparasitic mites is under-explored regarding the ecology of triatomines and Chagas disease transmission. Methods: Triatomine collections were performed using three common entomologic techniques in 2020–2021 from four different locations in southern Arizona and New Mexico. Triatomines were analyzed visually under a 112.5× microscope for the presence of externally attached mites. Following mite removal, triatomines were tested for T. cruzi infection by PCR. Results: Approximately 13% of the collected triatomines had mites securely attached to their head, thorax, abdomen, and legs. More than one mite attached was a common finding among ectoparasitized triatomines. Mite presence, however, did not statistically influence triatomine T. cruzi status. Conclusions: Our findings add to a growing body of literature demonstrating the sustainability of mite-infested triatomine populations throughout the Western Hemisphere. Future investigations are warranted to better understand the biologic impact of triatomine mites and their potential to serve as a potential biological control tool.

Vitis Species from the Southwestern United States Vary in Their Susceptibility to Powdery Mildew

The European grapevine (Vitis vinifera L.) has been cultivated in North America for about 500 years. One of the major limitations to its culture is the powdery mildew (PM) fungus, Erysiphe necator Schw. This study reports on the most extensive screening of Vitis species from the southwestern United States and northern Mexico for resistance to PM, testing 147 accessions of 13 Vitis species. In addition, Vitis vinifera cv. Carignane, a highly susceptible wine grape cultivar, was used as a reference to evaluate the effect of the inoculum 14 days postinoculation. Inoculation was done with a vacuum-operated settling tower using a broadly virulent isolate of E. necator, the C-strain. Resistant accessions (nine), moderately susceptible accessions (39), and highly susceptible accessions (99) were detected. The resistant accessions were then inoculated with an additional fungal isolate, e1-101, and they retained their resistance. Vitis species susceptibility was not associated with a North-South gradation, but Western species were more susceptible than Midwestern and Eastern species. All five of the V. monticola accessions were susceptible, as were the accessions of V. treleasei. The species V. acerifolia, V. candicans, V. cinerea, and V. × doaniana had significantly more resistant to moderately susceptible accessions compared with V. arizonica, V. berlandieri, V. californica, V. × champinii, V. girdiana, V. riparia, and V. rupestris, which had relatively more susceptible accessions than the other species. This research identified new sources of PM resistance in Vitis from the southwestern United States that could be incorporated into PM resistance breeding programs throughout the world.