Adult - The mature stage of an insect which occurs after the nymphal or pupal stage. Adult insects have mature sexual organs and usually have wings.
Deadheart - Dead standing rice tiller caused by stem borers girdling its base.
Diapause - A period during which the development of the insect is temporarily interrupted.
Economic threshold - The pest density at which artificial control measures should be applied to prevent an increasing pest population from reaching the economic injury level; a threshold which tells the farmer when he must take action to prevent a pest outbreak.
Egg - In insects, the reproductive body where the embryo develops and from which the nymph or larva emerges.
Egg mass - A group of overlapping eggs deposited by the female insect, such as the egg mass of yellow and striped stem borers.
Larva - The immature stage occurring between the egg and pupal stages in the life cycle of insects having complete metamorphosis.
Exoskeleton - The outer covering of the insect that provides support.
Nocturnal - Active at night.
Oviposit - In insects, to lay or deposit eggs.
Pupa - A nonfeeding and usually inactive stage which occurs between the larval and adult stages of insect development.
Sexual dimorphism - A condition wherein the male and female adult insects differ in appearance, as in yellow stem borers.
Whitehead - White, empty panicles resulting from the attack of stem borers which cut the lower portion of the stem.