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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Insect Genetics and Biochemistry Research » Research » Publications at this Location » Publication #132456
Title: COMPARISON OF THE FEEDING PROCESS OF NYMPH AND ADULT WHITEFLIES

Author
item Nelson, Dennis
item Buckner, James
item FREEMAN, THOMAS - NORTH DAKOTA STATE UNIV

Submitted to: Silverleaf Whitefly Research, Action and Technology Transfer Plan
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/2002
Publication Date: 3/31/2002
Citation: Nelson, D.R., Buckner, J.S., Freeman, T.J. 2002. Comparison of the feeding process of nymph and adult whiteflies [abstract]. Silverleaf Whitefly Research, Action and Technology Transfer Plan. p. 76.

Interpretive Summary:

Technical Abstract: With scanning electron microscopy we have examined the feeding processes of nymph and adult whiteflies. The Bemisia argentifolii adult feeding apparatus consists of a four-segmented labium in which is contained a slender stylet bundle (1.5-2 micrometers in diameter), consisting of two mandibles and two maxillary stylets. The stylet bundle of the adult is completely contained within the groove in the labium when not feeding. To penetrate the leaf, the adult places the tip of the labium against the leaf and then lowers its head in order to slide the stylet bundle down the labial groove and push the tip of the stylet bundle into the leaf. The length of the stylet bundle, averaging 217 micrometers, is sufficient to allow the adult to reach phloem tissue from any position on the leaf, from either abaxial or adaxial surfaces. The total length of the adult stylet bundle is determined by measuring the distance from the junction of labial segments 1 and 2 to the tip of the labium of non-feeding adults. The length that the stylet bundle has penetrated the leaf can be determined by measuring the distance from the junction of labial segments 1 and 2 to the position of the head (where the stylet bundle enters the labial groove) along the labial groove. This distance varied from 43 to 151 micrometers indicating that the adult uses less than 70% of the length of its stylet to reach a phloem bundle in cotton. The distance from the abaxial epidermal surface to the phloem in the cotton leaves we examined ranged from 53 to 127 micrometers. The stylet bundle of the immature whitefly, Bemisia argentifolii, appears to be looped or coiled within the body. The end of the bundle enters a groove in the rostrum and extends beyond the rostrum tip. In order to penetrate the leaf, the nymph extends the stylet bundle beyond the tip of the rostrum in an unknown manner. The length of the stylet bundle ranges from a minimum of 110 micrometers in the crawler to a maximum of 200 micrometers in the 4th instar. The length of the stylet bundle is not proportional to the length of the nymph. From the crawler to the 4th instar the length of the bundle only increased 39% while the length of the nymph increased 168%. The length of the nymph stylet bundle appears to be of sufficient length to reach phloem from any position on the leaf surface.