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
Sugary drink tax subsidize healthier foods like fruits and vegetables. The imposition of a sugar tax means that sellers of sugary drinks would have to increase the price of their goods by an amount P2 from the original price X, and then take on the rest of the tax themselves (P1) in the form of lower profit per unit sold. The tax burden on consumers (P2) makes it more expensive for consumers to buy sugary drinks and hence a higher proportion of their incomes would have to be spent to buy the same amount of sugary drinks. This decreases the equilibrium quantity of