|Chu, Chang Chi|
|Freeman, Thomas - ND STATE UNIV. FARGO, ND|
|Natwick, Eric - UCA COOP EXT HOLTVILLE CA|
Submitted to: Journal of the Agricultural Association of China
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2001
Publication Date: January 1, 2002
Citation: Chu, C., Freeman, T.P., Buckner, J.S., Nelson, D.R., Natwick, E.T., Henneberry, T.J. Bemisia tabaci (homoptera: aleyrodidae) b biotype: factors affecting leaf habitat, ovipostion, feeding site selection, host finding, and host preference. Journal of the Agricultural Association of China. 3 (1)48-64 Interpretive Summary: In this report, we summarized our research results in the last decade on the study of cotton plant-silverleaf whitefly (SLW) interactions to identify mechanisms of plant resistance. Lower leaf surface habitat of SLW may be related to the easiness of access to phloem tissues for feeding and leaf thickness may be a genetic trait that can be manipulated for SLW control. Selection of egg laying and feeding sites does not appear to use epidermal cell shapes or branched trichomes as surface cues. The mechanisms of adult and nymphal searching and feeding on phloem tissues are unknown and remain to be areas for further research. Host preference of SLW may be related to the abundance of vascular bundles in the leaf tissues. Adult SLW are attracted to green and yellow region of light spectrum, but little is known whether color plays a role in the host finding and selection. Relationships between SLW and plant characteristics are mostly remained in the stage of hypotheses. Manipulation of the plant characters for the control of SPW is desirable and should be investigated further. Based on our study of SLW behavior, we have developed 1) a new whitefly trap that appears to useful in monitoring population changes year round, and 2) a white reflective mulch strategy to reduce whitefly populations and insecticide use for the production of broccoli.
Technical Abstract: Incorporation of plant characteristics imparting resistance to sweetpotato whitefly (SPW) Bemisia tabaci (Gennadius) B biotype attack appears to be a viable approach to population management. We have conducted a series of studies to identify mechanisms of plant resistance. SPW eggs are laid mostly on abaxial leaf surfaces between veins and anchored in epidermal cells by insertion of pedicels into the leaf tissue. The pedicel is used as a conduit for uptake of water and solutes into developing eggs. Crawlers appear to randomly select sites for probing and feeding. Crawlers form salivary sheaths following penetration of abaxial leaf surfaces. Distance of phloem tissue from the abaxial leaf surface and leaf thickness may be related to probing and feeding site selection of crawler and its survival as such may have potential as genetic traits for breeding cotton varieties resistant to SPW. Adult in-season flight activity, seasonal distribution, and host finding and host preferences appear to be partially related to leaf color and leaf shape. Adult flight within the cotton canopy is generally directed toward younger leaves. After landing on host plant adaxial leaf surfaces, adults usually walk to shaded abaxial leaf surfaces to rest, feed, and oviposit. These observations have been useful for developing an adult whitefly trap for monitoring SPW population density and dynamics, and in developing white reflective mulch strategies to reduce whitefly populations and insecticide use in broccoli production.