Fuzzy, But Not Cute

Appearances can indeed be deceiving.  When I saw the white fuzzy stuff on the flower stalks of the hostas, I thought “must be a woolly aphid” and kept going.  Then it appeared on the Joe-Pye, the wild senna, and the dwarf lilac.  After receiving a phone call about this mystery critter, I took a better look.  These woolly aphids could jump!  Some searching revealed the proper identification:  citrus plant hoppers, a.k.a. mealy lantern flies or frosted lightning hoppers.  Gadzooks, what next?

Since I like the name “frosted lightning hopper” best, I’ll call these creatures FLH’s for short.  Scientifically, they are Metcalfa pruinosa.  The genus name honors entomologist Zeno “Zippy” Metcalf, a North Carolina State University researcher who was dedicated to the study of leafhoppers and their kin, while “pruinosa” means frosty, referring to the insect’s aforementioned fuzz.  They feed by sucking the sap from plants, and while a few FLH’s may not cause much damage, a higher population may induce stem twisting, stunting or dieback.  The fluff may also be off-putting to folks who like their plants neat, and might be troublesome to nurseries selling plants.  Perhaps most problematic is the waste stream of sugary liquid called honeydew which FLH’s emit.  This backdoor by-product lands on plant foliage and then grows a crop of an ugly black fungus called sooty mold.  If the FLH’s are high in a tree, the honeydew and resulting mold can land on patio furniture, parked cars or slow-moving pets, creating more clean-up work for the gardener and adding to the “honey do” list.

Just like I found in my own garden, the FLH feeds upon a wide variety of plants, including azaleas, magnolias, viburnums, and citrus trees.  A native to North America, it ranges over a large area, from Quebec to Florida, and west to California.  While we often complain of foreign insects invading our shores, we don’t often consider that our bad bugs go wandering, too.  This is in fact the case with the FLH, which is now found in parts of Europe, and has been causing problems in agriculture in South Korea.  May they’ll try a tariff.    

Life for FLHs starts out as eggs hidden in woody plant tissue or under tree bark.  Young nymphs hatch in mid-May.  These are covered in white waxy filaments, probably as a protective aid.  If you’re fortunate enough to be familiar with mealybugs or cottony cushion scales, these will seem superficially similar.  The adults, sporting a completely different look, are smooth, gray to brown, and wedge-shaped, with prominent yellow eyes.  I can reliably report that their vision is very good.  Each time I approached the infested hosta stalks with my secateurs to snip a sample, they moved slyly around the stem to hide.  But even more remarkable is their jumping ability.  Once I got my sample into the office, opening the bag allowed the FLH’s to jump several feet, onto the shoulders of the Master Gardeners, which caused a mixture of consternation bordering on fright.  They ain’t called “hoppers” for nothing.