PLATE 1.39. QUEEN ABDOMINAL SPIRACLES

TOP LEFT. Survey of the pleural portion of the first and second abdominal segments. The small spiracular apertures (one per segment) (arrow) are obscured by extensive hair cover. (x31)

BOTTOM LEFT. First abdominal spiracle on the propodeal segment of the thorax. This is the largest spiracle (along with its opposite side twin). Its elevated cuticular rim surrounds a shallow atrium, and the interior rim is the true opening into the tracheae. The tracheae are closed off from the inner (interior) rim by a sizable valve, which is incompletely Seen here because of a thin film of dried material emanating from the trachea. (x 240)

TOP RIGH T. Abdominal spiracle (upper left) With difficult\,, the covert and linear character of this aperture can be made out. ( x 37)

BOTTOM RIGHT. Higher magnification of aii abdominal spiracle. A cuticular hair fence of tergal orign incompletely covers this aperture, and several forms of hairs are present. The inner wall of the atrium Is replete with very short hairs. ( x 360)