As we move into the latter part of the growing season, it is time to consider late summer and fall pests as well as your plans for next year. Both stable and horn fly populations tend to decline over the dry, hot part of summer but can resurge in late summer into fall if sufficient rainfall occurs. Horn flies are found on the back and belly of the animals and stay constantly associated with the cattle host making topical insecticides (pour-ons, sprays and ear tags) effective control methods, with appropriate rotation. Stable flies in contrast feed preferentially on the legs of the animal for a short period of time (2-4 minutes), 1-2 times a day. This low contact time with the host makes chemical control difficult to achieve. Decaying hay and plant material is a primary breeding for stable flies, pay special attention to hay bale and feed wastage and surrounding crop fields.
House fly populations will continue to increase through the summer and can be a significant problem for feedlots and dairies. Minimize feed wastage spilled over bunkers and keep pens well scraped, paying special attention to areas around feed bunkers, water stations and under fence lines. Baits and traps can be useful against house flies, make sure the traps are placed away from buildings such as offices as they will attract flies to the location. Fall can also see face flies trying to enter barns and buildings for a place to overwinter. Sealing off cracks and crevices can remove these overwintering spots. If a second fall fly population boom occurs, any early season on-animal interventions applied are unlikely to still be effective this late in the season. If reapplying products within the same season, do not change insecticide group. Typing your insecticide active ingredient into this website will tell you which group it belongs to (https://iraconline.org/mode-of-action/classification-online/).
Larvae of the cattle grub should be treated in fall or early winter using oral medications or pour-ons. Treatment should not be carried out in January or February due to the potential for severe reactions. Lice populations also tend to thrive in cooler weather, watch out for patches of hair loss and rubbing, indicative of lice problems. Part the hair, especially along the neck and back of the animal and look for small cream insects about 1/16th of an inch. If large numbers of lice are observed, pour-on treatments can effectively treat lice infestation. Treatment must be repeated after two weeks to target any nits that were not killed after the first treatment.
Alicia Boor is the Agriculture and Natural Resources agent with K-State Research and Extension – Cottonwood District. Contact her by email at aboor@ksu.edu or call 620-793-1910.
