A couple of insects are threatening livestock in the U.S. On top of the list is the New World Screwworm. that reemerged in northern Mexico from 2023-2025 because of a breakdown in a biological barrier that had been established in Central America, along with illegal livestock movements, rapid northward spread of the insect from Panama, and reduced surveillance. The USDA announced that it is reallocating aircraft for dispersal of sterile male screwworm flies in Mexico, to reestablish a barrier along the U.S.-Mexico border, starting in the state of Tamaulipas and ending 50 mile north of the Texas/Mexico border. The process starts with irradiating NWS pupae, which creates sterile male flies that are then dispersed from airplanes in areas where female screwworm flies are located. Since NWS females mate only once in their lives, the female flies lay unfertilized eggs. Scientists point out that the Sterile insect technique is an effective tool for controlling and eradicating NWS, when paired with surveillance, movement restrictions, education and outreach. Until the 1960s, the screwworm was a serious pest in the Southwest and Southern U.S., causing losses of livestock, infection of pets and humans. Mass production of irradiated flies has kept the pest at bay in Mexico until recently. Also, cattle that had come from further south in Mexico brought the pest back north, infecting animals in Mexico that were within a couple of hundred miles from the U.S. southern border. Even though the northernmost active case is about 200 miles away from the U.S., the USDA is asking residents who live near the southern border to check their pets and livestock for signs of the Screwworm, and report suspected infections to their state animal health official or USDA area veterinarians.
Another insect, the Asian long horned tick is of concern to livestock producers and people too. The insect is native to east Asia, and were first detected in New Jersey in 2017, and have spread to 21 other states in the eastern United States. They look similar to other tick species, are light brown and very small, and have infested sheep, goats, dogs, cats, horses, cattle, chickens, wildlife and humans. They may be capable of carrying a number of tick borne diseases such as Rocky Mountain spotted fever.
Over the past couple of weeks, I’ve reported on the snowpack for the Upper Colorado, San Miguel Dolores, Animas and San Juan River Basins, which are all hovering about 50% of normal, and that doesn't give our region much time to catch up on a snow pack that will boost water levels in reservoirs this year. But according to Johnathan Overpeck, Dean of the School of Environment and Sustainability at the University of Michigan, and Brad Udall of the Colorado Water Center, Colorado State University, much of the Southwestern U.S. is experiencing a mega-drought, that started in 1999, caused by warming temperatures and reduced precipitation from winter snow. Another study by University of Colorado Climate scientist Jeremy Klavans, looked at sea surface temperatures, which influence the amount of precipitation the western U.S. receives. For most of the past thirty years, ocean temperatures have been cooler than normal, and that caused lower precipitation in the western U.S. He contends that the cooler ocean temperatures have likely been caused by carbon emissions and climate change. Currently, the entire Colorado River reservoir system holds 21.9 million acre-feet of water, or about 37% of its total 58 million acre-feet capacity.
19th century businessman Dwight Morrow wrote, Any party which takes credit for the rain must not be surprised if its opponents blame it for the drought.
Link to Overpeck and Udall report: https://www.colorado.edu/center/gwc/2025/12/03/colorado-river-insights-2025-dancing-deadpool
Link to Jeremy Klavans report: https://www.colorado.edu/today/2025/08/14/human-emissions-drove-megadrought-western-us
