|Freeman, Thomas - NORTH DAKOTA STATE UNIV|
Submitted to: Microscopy Society of America Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: April 25, 2000
Publication Date: N/A
Technical Abstract: The silverleaf whitefly, Bemisia argentifolii, has become a very serious agricultural pest, feeding on a wide variety of crops in the southern U.S., and in tropical and subtropical climates worldwide. Theory had proposed that whiteflies fed and oviposited on the abaxial surface (underside) of leaves due to the closer proximity of phloem tissue to that leaf surface. However, our recent observations indicated that the feeding apparatus of the adult was long enough to reach the phloem from any position on the leaf without regard to leaf vein density. Using scanning electron microscopy, we have shown that the length of the feeding apparatus of both adults and nymphs is sufficient to reach a phloem bundle from any position on the leaf. The adult feeding apparatus consists of a four-segment labium and a slender stylet (1.5-2 um in diameter). The first labial segment appears to be an extension of the thorax. There is a deep labial groove in the distal segments two, three and four, and the 4-component stylet is contained within the labial groove. In the feeding process, the tip of the labium is placed against the leaf surface. The adult then lowers its head sliding the stylet in the labial groove and out the end of the labium and into the leaf. The length of the stylet corresponds to the total length of the 3 distal segments of the labium. The measured length of the adult stylet ranged from 132 to 313 um.