Neuroendocrine Control of Drosophila Larval Light Preference

Looking for the Dark

Mature Drosophila larvae wander away from food and seek a dark site for pupation. While investigating this phenomenon Yamanaka et al. (p. 1113 ) found that four prothoracicotropic hormone (PTTH)–producing neurons mediate light preference in the central brain. PTTH circulates in the hemolymph and signals via its receptor, Torso, to two light sensors, sensitizing them for light detection. The larvae can then transform from wandering larvae into immobile pupae hidden from light and predatory eyes.