Two scoops on scales

Dear Readers,

When my Dear Editor asked me to write about soft scale insects, I was unprepared for the onslaught of negativity surrounding this bug. There are no fun facts or cute videos about scales, and there’s lots of material on annihilating them. You may share that perspective. But in the interest of complete coverage, I sought out an alternative opinion and found this…

Through the eyes of a scale

Samantha Scale here, with BUGNEWS, reporting live from your backyard on the bug everyone loves to hate — me. (Honestly, I’d prefer to be a butterfly but nobody asked.) I’m here to get the word out on what you call scales, but I call heroes.

First, some background. Scale insects belong to the order Hemiptera (“true bugs”), and the superfamily Coccoidea, which contains about 8,000 very diverse species world-wide, 1,000 of which are found in North America.

In Ohio, look for brown, cottony maple, European elm, fletcher and lecanium scales. We are ectoparasites — we live on the outside of plants and stick our stylets (needle-like slender tubes that can be up to 8 times longer than our bodies) into plants and suck out phloem tissue. Yes, I know it sounds gross. No, we are not related to vampires.

The three most common types of scale families are soft, armored and mealybugs, but we’re just talking soft scales today.

BUGNEWS asks tough questions — like, are scales pests? Absolutely not!

We are tiny bugs who lead a hard life and deserve respect. Our species can vary from the really small (1/8 of an inch long brown scale) to the small but relatively a lot bigger (½ inch long magnolia scale.) You try surviving at that size!

To help, females produce a round or oval domed wax cover that sticks to our bodies. This white, grey, or brown coating looks like the scale of a fish — our name, get it? — and keeps us from drying out, provides camouflage from predators, and protects us from YOUR poisons. Preeetty amazing!

And what do male scales do to survive? They don’t. Gnat-ish creatures with tiny wings, our males mate and die, without even time for a meal. Oh well.

Moms lay up to 2,000 eggs under their wax covers that hatch in 7-21 days; some species have live young. Soft scales go through three instars (growth phases). Baby nymphs (crawlers) move around their birth plant on tiny legs to find their new home. Once it finds the perfect spot, mouthparts (stylets) go in, phloem comes out, and the crawler loses the use of its legs. Most species remain immobile for the rest of their lives. Is this any way to live? You should be holding fundraisers for us.

Yet despite this hard (and boring) life, we play an important role in the ecosystem. We excrete honeydew (excess sap from phloem), which is a sticky, but yummy food source for flies, wasps, ants and birds. We scales also contribute to your economy, as some are used to produce dyes to color food and fabrics (cochineal scales), while some control invasive plant species.

So here’s to the noble scale! Next time you see one, give it a smile! I’m Samantha Scale, signing out for BUGNEWS.

A second take on scales

Dear Readers,

After seeing Samantha’s report, I felt compelled to add the following. BUGNEWS appears to have, ahem, a slight bias in its reporting.

Sadly, Samantha, people really do hate you. Your non-stop feeding can harm and, if infestation is heavy enough, kill plants. Leaves yellow or wilt, growth is stunted, branch tip dieback occurs. Damage starts on individual limbs and spreads to the entire canopy. Plants weakened by scale are more susceptible to drought, disease, severe weather and other insect attacks. The only plus about soft scales is they are less harmful than armored ones.

And that wonderful honeydew? Honeydew creates a sticky, unsightly mess that coats cars, houses, sidewalks, benches and anything else unlucky enough to be dripped on. It attracts ants, wasps and flies, which people don’t usually want around. While honeydew doesn’t damage plants, it supports sooty mold, which is ugly and interferes with photosynthesis. 

How to stop scales

Natural controls include predators, such as lady beetles and parasitic wasps, and adverse weather conditions. Look for scales before purchasing plants, but they can be hard to spot. Once you find scales, identify the species. This will help identify the timing of the crawler stage, when they have no covers and are most vulnerable.

Scales may be scraped or rinsed off if infestations are small; heavily infested stems can be cut away. Once scales have their hard coatings, contact insecticides won’t work, but horticultural oils and soaps may, as well as systemic pesticides. Here are resources to help you identify the best solution for your scale problem. Just smile when you blast ‘em…

More links for reading:

SCALE INSECTS ON MINNESOTA TREES AND SHRUBS: University of Minnesota Extension

CONTROLLING SCALE INSECTS AND MEALYBUGS: Alabama A&M and Auburn Universities

SCALE INSECT CONTROL: Nebraska Extension (short version)