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 the two neighboring cities. A 2017 before and after study has concluded that one year after the tax was introduced in Berkeley, sugary drink sales decreased by 9.6% when compared to a scenario where the tax was not in place. This same study was also able to show that overall consumer spending did not increase, contradicting the argument of opponents of the Sugary Drink Tax. Another 2017 study results were that purchases of healthier drinks went up and sales of sugary drinks went down, without overall grocery bills increasing or the local food sector losing money. Democratic Philadelphia mayor Jim