Galeae

Galeae (singular galea) are the lateral lobes of the maxillae, one of the paired mouthparts in insects. The galea is most conspicuous in Lepidoptera, where each maxilla bears a long galea; the two galeae can come together to form a long, slender proboscis used for siphoning liquids such as nectar. The inner surfaces of the galeae commonly bear sensilla and other structures that aid in feeding and chemical perception.

Function and form vary across insects. In Lepidoptera, the galeae are adapted to create a continuous food canal within the proboscis, enabling efficient uptake of liquids. In many other insect groups, galeae may be reduced or modified and may not participate in a feeding tube; the maxillae can take on a range of roles, including manipulation of food or sensory input rather than the formation of a siphoning apparatus.

Taxonomic usage and morphology of galeae reflect the diversity of insect mouthparts. While the term galea refers specifically to the maxillary lobe, galeae as a pair are most characteristic of nectar-feeding lepidopterans, with their structure and degree of development varying among species. The name derives from the Latin galea, meaning helmet or hood, a reference to their shape in some species.

See also: maxilla (insect), proboscis, labium, insect mouthparts, chemoreception.