Effects of the chicken body louse, Menacanthus stramineus, on caged layers.

When 23-, 35-, and 49-week old Ideal 236 White Leghorn hens were infested with the chicken body louse, Menacanthus stramineus, percentage egg production 12 weeks later had decreased by 16, 34, and 46%. Meanwhile, the average hen weight had decreased by about 85, 300, and 450 grams compared with unifested control hens of the same age. There were also significant decreases in clutch size and feed consumption of the infested hens. All the decreases correlated with populations of lice.