PLATE 1.6. QUEEN ANTENNA SURFACE

BOTTOM RIGHT. Last five segments of the queen antenna. The antenna surface is profusely covered with a variety of uniformly distributed sense organs. On each segment, usually at the proximal and distal border, are small clusters of pit organs, which appear as bright spots. (x 144)

TOP RIGHT. Terminal segment of queen antenna. A few stout peg organs (sensilla basiconica) and stout long pegs are seen among the majority of sensory hairs. The plate organs are not visible. ( x 270)

TOP LEFT. Medial surface of the second antenna segment of the queen. A few pit organs show brightly. It is not known why these pit organs reflect more secondary electrons to the scanning electron microscope collector and therefore appear brighter. The faint circular outlines of the plate organs are visible. (x 330)

MIDDLE LEFT. Higher magnification of the surface on the penultimate segment of the queen antenna. The bright pit organs are relatively sparse but are aggregated. Placoid (plate) and trichoid (hair) sensilla surround the pit organs. ( x 2,200)

BOTTOM LEFT. Close-up of a plate organ and several trichoid sensilla. The crack that extends along the outer rim of this plate organ is probably artifactual. At this magnification the subtle cuticular ribbing relief around the organ's periphery is visible. Exquisitely small pores (not visible) line these ribs and permit odorant molecules to enter and make contact with the sensory dendrites circumferentially arrayed under the plate. (x 5,500)