Sex and Caste Specific Eye Structures in Stingless Bees and Honey Bees (Hymenoptera: Trigonidae, Apidae)
Ribi, Willi. A; Engels, Elisabeth; Engels, Wolf
Morph-specific structural differences of the compound eyes and the ocelli were studied by means of corneal replicas, semi-thin sections, and SEM. Drones have enlarged compound eyes, especially in the honey bee, with a region of large ommatidia in the fronto-dorso-medial part. In male stingless bees and in workers and queens of both stingless and honey bees, this region points in fronto-ventro-medial direction. The possible role of the corresponding visual fields in detection of flowers and mates is discussed with special reference to mating biology. Localization of the queen by the drones during the nuptial flight apparently depends more on visual cues in honey bees, and more on pheromonal signals in stingless bees. The relatively large male ocelli in the stingless bee possibly are important for measuring critical light intensities for leaving drone aggregations in time before dusk. The visual system in general seems to be less derived in the queen morph.