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 Sugary drink tax A sugary drink tax or soda tax is a tax or surcharge designed to reduce consumption of drinks with added sugar. Drinks covered under a soda tax often include carbonated soft drinks, sports drinks and energy drinks. The tax is a matter of public debate in many countries and beverage producers like Coca-Cola often oppose it. Advocates such as national medical associations and the World Health Organization promote the tax as an example of Pigovian taxation, aimed to discourage unhealthy diets and offset the growing economic costs of obesity. Type II diabetes is a growing health concern