PLATE 1.22. QUEEN WING BASE SCLEROTIZED PLATES

TOP LEFT Base of the forewing (the head is to the tipper left). The hairy tegula partly covers the triangular humeral plate.

TOP RIGHT. Hair plate of socketed (presumed) mechanoreceptors on the interior edge of the humeral plate. Electron beam damage probably caused the bending and twisting of hairs. Rotational movements of the tegula and hurneral plate bend these hairs; if innervated, they could monitor such dislocations. ( x 66)

MIDDLE LEFT Another view of the forewing base showing the upraised humeral plate. The arrows point to structures shown in far higher magnification cation on the bottom left, bottom right, and middle right micrographs ( X 1'5 0)

BOTTOM Close-tip of the radius vein. Branched hairs emanate from this part of the wing base. Structures surrounding this vein base are visible in the middle left micrograph, indicated by the left arrow. (x 2,600)

MIDDLE RIGHT. Condylelike projection at the wing base with hairs aparentlyly in contact with the wing margin. Hairs project at different levels and angles from this knob. These hairs, if innervated, may be mechanoreceptors recording wing beat frequency and/or tension and flexion of the wings. A low-magnification view of this structure in relation to other wing structures is in the middle left micrograph (right arrow) ( x 300)

BOTTOM RIGHT High-magnification view of a fascicle of about 20 socketed hairs in a cuticular protuberance at the wing base. Features adjacent to this structure are visible in the middle left micrograph (middle arrow) These hairs, if innervated, may be m echan o receptors monitoring a single kind of temporal displacement, such as the upstroke or downstroke of the wing. ( x 60)