التعريف: Insect mouthparts that are concealed inside the head by folds of the head capsule. The mandibles and maxillae are located inside the oral chamber, and only the tips of the mouthparts protrude from the oral opening.
التعريف: Eye-spots which may be set into a pit to reduce the angles of light that enters, to allow the organism to deduce the angle of incoming light. Lens-like structures may be present, but stemmata, unlike lens eyes, cannot form an image, either for lack of refractive power or retinal resolution.
