At the height of lavender season in Provence—the largest lavender- producing region in the world—the industry is worried. The iconic flower is in trouble and the culprit is the cicadelle, a tiny insect with a voracious appetite. Production has plummeted in the last decade, dropping to as little as one third of what it was in 2000. Although lavender grows wild in many areas of the world and is cultivated in many countries (notably England, Spain, Bulgaria and the three west coast states of the U...