A persistent virus will eventually lose its abilty to cause an infection. Allergens from fleas and cockroaches in a home or office may stimulate antixenosis. Systemic insecticides are translocated through the vascular system of a plant or the circulatory system of an animal. At the economic threshold, the cost of damage equals the cost of control.
Environmental persistence is regarded as a major disadvantage of the synthetic pyrethroids.
B. Sticky trap D. None of these 9. A beetle that feeds on kudzu. B. A parasite of lady beetles. C. A predator of robber flies. A viral pathogen of lacewings.