pupal stage to adult, or other life
processes of insects.Miticides (acaricides) Kill mites that feed on plants and
animals.Microbial pesticides Microorganisms that kill, inhibit, or
outcompete pests, including insects
or other microorganisms.Molluscicides Kill snails and slugs.Nematicides Kill nematodes (microscopic,
wormlike organisms that feed on
plant roots).Ovicides Kill eggs of insects and mites.Pheromones Biochemicals used to disrupt the
mating behavior of insects.Plant growth regulators Substances (excluding fertilizers or
other plant nutrients) that alter the
expected growth, flowering, or
reproduction rate of plants.Repellents Repel pests, including insects (such
as mosquitoes) and birds.Rodenticides Control rats, mice, and other
rodents.(ii) Identify and discuss TWO positive effects of pesticide use. (2 points
maximum. 1 point for each correct positive effect and explanation.) (1) Plants are
directly and indirectly humankind’s main source of food. They are attacked by
tens of thousands of diseases caused by viruses, bacteria, fungi, and other
organisms. There are over 30,000 kinds of weeds competing with crops
worldwide. Thousands of nematode species reduce crop vigor, and some 10,000
species of insects devour crops. It is estimated that one-third of the world’s food