linguatulosis, invasions caused by Lin-guatula serrata, Porocephalus armillatus, and other linguatulid arachnids.

Adult linguatulids (males, about 20 mm long; females, 130 mm) live parasitically in the nose and frontal sinuses of predatory animals; the larvae invade the liver, lungs, and other organs of cattle and, often, of man. Infestation may occur through food contaminated with the nasal discharges of dogs and other animals afflicted with the parasites.

The adult Porocephalus (males, about 50 mm long; females, 120 mm) parasitizes in the respiratory passages of tropical snakes (for example, pythons); the larvae infest the viscera of man and certain animals through products contaminated with snake excretions containing the parasites’ eggs. In man, the course of linguatuliasis is generally asymptomatic, but pneumonia, jaundice, and intestinal obstruction sometimes develop. Thorough washing and scalding of vegetables to be eaten help to prevent the condition.