Look closely for patches of affected perennial ryegrass turf with small, brown leaf and stem lesions. Warm, wet weather exacerbates foliar blighting. Anthracnose is being diagnosed frequently in highly stressed, under fertilized, and low cut greens and fairways. If symptoms develop, increase turf vigor with proper irrigation, light rates of nitrogen, raise cutting heights if possible, and switch to solid rollers. Several fungicide tank mixes are labeled for control, but to be effective they must be applied in conjunction with stress reduction.
Armyworms are still in the news.
It seems like all fescue decline is being blamed on these insects. Most turf will recover from attacks, but patience is required. The hot summer weather doesn't help, but light rates of fertilizer and regular moisture will improve your odds of turf over weeds. Overseed large affected areas with improved turfgrass cultivars.