Legend has it that Martin Luther was the first to bring an evergreen indoors and decorate it with candles to celebrate the birth of Christ. Since then, people around the globe have embraced the tradition of decorating the Christmas tree. In addition to candles, glass ornaments, and lights, flocking has become a common element of the decorating agenda in many households. Various materials have been used for flocking including cotton, wool, and foamy synthetic products that can be squirted from an aerosol can. Where is this going? Has the bug guy finally cracked up? Bear with me. This week I was delighted to see one of Mother Nature’s tiny creatures decorating my trees and shrubs with a fine coating of white wax. Ah, Christmas arrives in June.
A profile shot reveals a flatid nymph adorned with white wax.
The curious insects responsible for this “flocking” are members of the family Flatidae, also known as the flatid planthoppers. These sucking insects are close relatives of other well known sap-suckers such as aphids and leafhoppers we met in previous episodes of Bug of the Week. They feed by inserting a small beak into the vascular system of a plant and withdrawing the nutrient-laden sap into their bodies using a small hydraulic pump located in their head. As a byproduct of this feeding, they excrete a sticky substance called honeydew that attracts other insects such as wasps and ants and serves as a substrate for the growth of a harmless fungus called sooty mold. They also secrete a pure white wax from glands lining their abdomen. The function of this wax may be as protection from tiny wasps that might like to sting them and deposit eggs into their bodies. Or the wax may confuse hungry predators such as lacewings and ladybugs that might want to eat them, but are bamboozled by their waxy ruse. Whatever the purpose of the wax, it is produced in prodigious amounts.
Adults flatids are cloaked in a waxy bloom.
Flatid nymphs hatched from eggs inserted in the stem of the plant last year by the adult planthopper. Now, the nymphs are beginning to molt and will soon become adult hoppers that will remain on our plants for the duration of summer and into autumn. Adult planthoppers do not produce vast amounts of wax as they did in their youth, but their bodies are coated with a lovely bloom of grey, green, or bluish wax. They are common on roses, dogwoods, locusts, privets, hollies, maples, and many herbaceous perennials and annuals.
Flatid planthoppers have been reported to cause the terminals of small plants to droop due to their feeding. Females inserting large numbers of eggs into the stems of plants may also cause small branches or seedlings to die. However, in general, flatid planthoppers cause very little injury to the plants in our gardens and the use of insecticides to eliminate them is unwarranted. With the arrival of hot, humid, dog-days of summer, they seem to be a welcome reminder of cooler times to come.
References
Bug of the week thanks David Clement, Paula Shrewsbury, and the Master Gardeners of Calvert and St. Mary’s counties for providing the inspiration for this episode.
To learn more about these waxy wonders, please visit the flowing web sites:
http://www.forestpests.org/ash/flatidplant.html
http://www.entomology.umn.edu/cues/Web/187Planthopper.pdf
http://entnemdept.ufl.edu/creatures/orn/shrubs/citrus_flatid_planthopper.htm