scale insects: ... The body is covered by a protective waxy shell, often resembling scales or cottony cushions, that gives these insects their common name ... (Encyclopædia Britannica 2006)

scale insect: any of numerous small prolific homopterous insects (superfamily Coccoidea) that have winged males, wingless scale-covered females attached to the host plant, and young that suck the juices of plants and some of which are serious pests (Merriam-Webster Online Dictionary 2005)

scale insect: Any of various small homopterous insects of the superfamily Coccoidea that suck the juices of plants, the females of which secrete and remain under waxy scales on plant tissue. (The American Heritage Dictionary of the English Language 2000)

scale insect (noun, biol): any of various small bugs that feed on the sap of plants, including several serious pests of crops, the adult female of which is usually covered by a protective scale-like waxy or horny covering. (Chambers Reference Online 2006)

scale insect: small homopterous insect that usually lives and feeds on plants and secretes a protective waxy covering ... http://www.wordreference.com/definition/scale...

Stimme holger zu.

NOAD:
scale - 3: a flaky deposit, in particular:
• a white deposit formed in a kettle, boiler, etc., by the evaporation of water containing lime. • tartar formed on teeth. • a coating of oxide formed on heated metal.
scale insect - a small insect with a protective shieldlike scale. It spends most of its life attached by its mouth to a single plant, sometimes occurring in such large numbers that it becomes a serious pest.

OED:
scale² - 1. ... f. The protective covering of insects of the family Coccidae, which remains when they die and protects the eggs and afterwards the young beneath it; hence, = scale-insect; also, the diseased condition of plants caused thereby.
1822 Trans. Hort. Soc. (1826)

Webster's unabridged:
(5)scale - ... 8 a or scale insect also scale louse or scale bug : any of numerous small very prolific insects constituting Coccidae and related families of the suborder Homoptera, having young that suck the juices of plants, adult males that lack mouthparts and do not feed and have a single pair of wings, and adult females that are usu. permanently attached to the host plant, structurally degenerate with most of the external differentiation lost, and often obscured by a waxy or powdery secretion that protects the female and her eggs, and including many extremely destructive pests of economic plants as well as a few that yield valuable products -- compare COCHINEAL, LAC b : infestation with or disease caused by scale insects [our roses are full of scale this year]

web examples:
• I now have scale on all four schef[flera] plants.
• You have scale. I've never had an infestation that large so I can't tell you ...
• It was happy in the beginning, new growth, but now it appears to have scale.
• Q I have scale on several of my houseplants. How can I safely control it? A In a nutshell: The only surefire cure is to throw the affected plants away.
• Q. I was told I have scale on several of my houseplants.
• I've never had scale on any of my houseplants so I don't know if the scale falls off or if you have to scratch it off.
• It is a very rare occurance I have a pest problem on any house plants. Haven't had scale, aphids, a mite or anything else in at least 3 years.
• In it's second year it had scale, I treated it and thought it was gone
• Question: I am wondering what causes scale on house plants. The plants I have that get scale are not near other plants.
• My Calamondin got scale (I think it came with it)
• The little brown spots aren't scale, are they? ... If they're raised and you can scrape them off, you've likely got scale -- not uncommon on these ferns.
• Most common problems are scale, mealybugs, and spider mites.
• The other problem could be scale causing the plant to defoliate.
• The fuzzy stuff on the trunk could be scale and would need to be sprayed with a dormant oil in January.
• Is this scale on shefflera? ... I have tried to scrape off these growths, but it doesn't come off easily, and I have seen/scraped scale off plants before and this isn't like that. ...
That is not scale, you would know if it was. Scale is almost impossible to get rid of. When a plant is infested with scale, a sticky honey like substance drips and accumulates on the branches.
• As it turned out it was Scale. ANd the FInger Lime was full of it.

To most speakers, I don't think 'scale' is really normally the word for the individual bug, but rather for the condition caused by it: the infestation as a whole, the diseased appearance of the leaves, etc. I assume it's because it looks like a flaky deposit or buildup (etymologically/conceptually similar to scale on your water pipes or your teeth), but that's just a guess.

But in any case, it's basically used as a noncount noun: a plant can have scale, get scale, suffer from scale, etc., but you can't (at least, I don't think you can) say *'a scale' or *'scales' the way you can say 'a scale insect' or 'scale insects.'

People use 'scale' to mean all the collective symptoms, but they call it 'it,' like a disease, a mysterious affliction in and of itself. If we had to paraphrase it, we'd probably just say 'that icky stuff.'

So 'scale - Schildlaus' still seems a bit misleading, or perhaps at best only formal/technical. 'Scale insect' is definitely worth adding, and for the normal, by far more common usage of 'scale,' I would suggest something like 'Schildlausplage' (apparently more common than 'Schildlausverseuchung'?), 'Schildlauskrankheit,' etc.

So the entry is actually questionable?


Google results, trying to prove that "scale" is also used for individuals:
"adult female scales" --- 175
"female scales" --- 9,350
"female scales" site:edu --- 388
"Adult male scales are tiny, winged and seldom seen"
http://www.muextension.missouri.edu/explore/a...

Habe gerade nachgefragt, Entomologin und anderer entomologisch versierter Mensch, beide USA, scale insect ist viel gebräuchlicher als scale für einzelne Viecher.

Well, no, not really, Webster's & OED both confirm it. But I suspect it's more entomologist-speak, scientific jargon -- since the rest of us never really have any reason to consider the bugs as individuals at all. You don't pick one off your plant and say, 'Look, it's a scale!'

This is another of the many cases where I wish LEO had a marking for [technical] to designate Fachsprache, but [Tech.] already means Technik, unfortunately. Or I wish that labels like [zool.] could be reserved for technical language, but that doesn't seem to be the policy.

Maybe 'scale' from the gardening perspective (which is basically the perspective of most speakers) should be marked [Bot.] or [Landwirts.] or something; I'm not too clear on what those labels are supposed to include.

*f5* That's basically the impression I get -- that it's used occasionally (possibly often just for the sake of brevity and/or variation) but not very often and not as the most usual choice.

Too common, though, to be marked [rare], probably. Maybe what I wish (again) is that LEO had a usage marking of [relatively uncommon], where the threshold for rarity wasn't so high.

What do your contacts (or reference sources) say about 'scale louse' and 'scale bug' (both from Webster's 3rd, 1961)? I think 'also]' in Webster's (sorry that came out so crunched above) denotes a less common variant, but I'm not sure how much less common. If we're including all the possibilities, though, those should perhaps go in as well, just for the record.

Contacts are gone. Seem to be even less technical:

Coccoidea "scale lice" --- 2 hits on Google
Coccoidea "scale bugs" --- 5
"scale lice" site:edu --- 17
"scale bugs" site:edu --- 48