Hemiptera plant. Phloem sap, which has a higher concentration of sugars and nitrogen, is under positive pressure unlike the more dilute xylem sap. Most of the Sternorrhyncha and a number of Auchenorrhynchan groups feed on phloem. Phloem feeding is common in the Fulgoromorpha, most Cicadellidae and in the Heteroptera. The Typhlocybine Cicadellids specialize in feeding on non-vascular mesophyll tissue of leaves, which is more nutritious than the leaf epidermis. Most Heteroptera also feed on mesophyll tissue where they are more likely to encounter defensive secondary plant metabolites which often leads to the evolution of host specificity. Obligate xylem feeding is a
Irving Tissue Irving Tissue Irving Tissue Company Limited is a tissue products producing company, owned by J.D. Irving Limited. It has manufacturing locations in both Canada and the United States. Irving Tissue was started in 1988 in Saint John, New Brunswick after J.D. Irving acquired a tissue paper mill from Kimberly-Clark in the city's west side (adjacent to Irving Pulp and Paper). Irving began producing tissue for a new subsidiary that was located in Moncton, N.B. and was sold under the marketing name Majesta. In 1990, J.D. Irving opened a tissue converting plant for Majesta in Dieppe, New Brunswick that would make