This past Sunday morning, I was dining beneath a large shade tree when suddenly I noticed that it was “raining”. This strange drizzle on a sunny day reminded me of one of my favorite songs by John Fogerty, “Have you ever seen the rain?" The stanza “Have you ever seen the rain, Comin' down on a sunny day” led me to wonder why in the world a shade tree would be raining on my breakfast. The persistent drip, drip, drip lead me to a small branch about 10 feet above the patio. On the twig I discovered a very large leafhopper commonly known as a sharpshooter.
The white chalky patch on the side of the shapshooter contains brochosomes. They will be used to powder the area where the sharpshooter lays her eggs. They may help protect the eggs from enemies or damaging substances.
Sharpshooters belong to a family of sucking insects known as Cicadellidae. These rascals eat by inserting straw-like mouthparts into a plant and tapping into its vascular system. The pipes they tap into are called xylem and, as plant tissues go, the xylem carries a fluid that is rather nutrient poor. As a result, sharpshooters must remove relatively large amounts of xylem fluid to obtain their requisite nutrients. The fluid is rapidly processed and the excess fluid is forcefully excreted from the anus as a liquid called honeydew. It is estimated that some sharpshooters process the equivalent of a human drinking nearly 400 gallons of water a day. No wonder a few of these buggers made it feel like it is raining. Determined to identify what was anointing me and my Sunday breakfast, I captured my six-legged friend and compared it to other specimens found in our insect museum. It was clearly in the genus Oncometopia and likely Oncometopia nigricans or, perhaps, Oncometopia orbona. Last year about this time I was fascinated by a curious inquiry about “raining trees” in the city of Baltimore. On a rather moist day, I did my best to investigate this strange phenomenon and removed several samples from the weeping trees with my long pole pruner.
I was seeking evidence that some honeydew-producer such as the tuliptree scale we met in a previous Bug of the Week was behind this mysterious rain. I found no evidence of the sedentary scales and left the scene unfulfilled, my instigation inconclusive. A few weeks after the visit last October, I received an envelope full of crushed bug remains from a concerned resident living nearby one of the “weeping trees”. I compared my newly acquired Oncometopia to the specimens sent to me last autumn by the Baltimorean and found the remains from the weeping trees indistinguishable from the rainmaker I collected above my patio. Hind sight is usually nearly perfect and my failure to find sharpshooters last autumn in the canopies of the raining trees is not really surprising. I’m guessing that when the sharpshooters saw my pole pruner approaching, they simple took wing and were long gone before the branch hit the pavement. Sharpshooters have excellent eyesight and are strong fliers. One thing is for certain, the sharpshooter above my tree made it rain on a sunny day. We will just have to wait and see if the mystery of the weeping trees returns to Baltimore this autumn and if sharpshooters are the rainmakers.
References:
We thank Jill Rosen for providing the inspiration for this Bug of the Week. To learn more about sharpshooters and raining trees in Baltimore, please visit the following web sites.
http://creatures.ifas.ufl.edu/fruit/sharpshooters/sharpshooters.htm
http://www.inhs.uiuc.edu/~rakitov/brochosomes.html
http://www.redorbit.com/news/science/698707/experts_face_off_on_tree_weeping_bug_expert_says_its/index.ht