Aphid stylet

FIG. 2 Measurements of intracellular potentials in sieve tubes of maize via severed aphid stylets. Stimulation by ice water (above) and electric shock (below) evoked action potentials which were propagated with a velocity of 3-5cms in a basipetal direction. (From Ref. 36.)... 

Phloem sap may be obtained by a variety of methods ranging from the use of aphid stylets to the cutting of vascular tissue. Recent techniques have involved the use of EDTA to prevent the resealing of phloem elements (King and Zeevaart, 1974) and successive cutting of the pod tip of Lupinus albus (Pate et al., 1974) and Glycine max (Fellows et al., 1978). A summary of some... 

Petroleum Oils JMS Stylet oil Whitefly, aphid, thrips, pysllids Various fruits and vegetables Insecticide... 

Tjalllngil, W. F. "Stylet Penetration Activities by Aphids" Dissertation, Agricultural University, Wagenlngen, The Netherlands. 1985, 100 pp. 

Aphids have flexible, stylet-like mouthparts adapted for probing of plant tissues. By this means, the aphid must use chemical cues from the plant to determine if the plant is a suitable host (host plant quality), where the aphid is on the plant, the location of the stylet within the plant tissues, and the direction to probe to locate the plant phloem (Campbell and Dreyer, 1990 Dreyer and Campbell, 1987). Aphids avoid many of the toxic compounds stored in plant cells by probing between the cell walls. These insects are able to penetrate the intercellular spaces by producing a variety of digestive enzymes which depolymerize the pectins and hemicelluloses forming the intercellular-cell wall matrix. Aphid-host plant compatibility is associated to the extent that these enzymes depolymerize their respective substrates, and a reduced rate of depolymerization is often associated with host plant resistance. Differences in methoxylation, acetylation, or neutral sugar composition in the matrix polysaccharides are often involved in this reduced depolymerization. Further, specific breakdown products from depolymeri-... 

---