Monday, June 13, 2011

So How Much Does an Aphid Weigh, Anyway?

If you have a blog, you have no doubt checked your blog statistics from time to time to see who's linking to you, how many people have visited, and the like. (C'mon. Admit it. I know you do.) The best part of this procrastinating is seeing the search terms people have used that led them to your site.

In checking out this feature last week, I saw that someone ended up here because they wanted to know "how much does an aphid weigh?"
I am sure they were disappointed, because my aphid post contained no weights and measures and was just a rambling about how...well, how darn cute the little guys could be.

Never mind that they are such pests and so utterly reviled--all 4,400 or so species of them. The garden writer in our daily paper called them "sucking insects that can cause serious havoc on most every kind of plant" just last week. Field guides and other books spare no words when it comes to describing them: "among the most destructive agricultural pests" (Audubon Society Field Guide to North American Insects and Spiders); "Major agricultural and garden pests" (Insects of the Pacific Northwest);  "pests of crops in temperate parts of the globe" (Encyclopedia of Insects).

Even dictionaries libel the little guys: "any of numerous small sluggish homopterous insects...that suck the juices of plants" (Webster's); "A family of minute insects, also called plant-lice, which are very destructive to vegetation" (OED); "a very small insect that lives on plants and destroys them" (Macmillan dictionary). (Hmm...the latter makes me think they could define a human as "a rather large primate that lives on planets and destroys them.")

The horror of aphids is legendary, as reflected in one online thesaurus site that offered no synonyms for "aphid" such as "ant cow" or "greenfly" but instead queried, "Are you looking for Bigfoot?"

Weight! Weight! Don't tell me! I forgot all about that weighty question about aphids (which, yes, are related to scale insects).

According to a writer of a monograph on aphids published in 1876, "Except for accidents, a single aphis in one year might produce more aphides than is represented by the weight of the population of China." As I am too lazy to find out (a) the population of China in 1876, (b) the weight of an average Chinese citizen, (c) the world population of aphids in 1876, and (d) the result of an equation involving division, we will glide right past this and simply seize information from a more modern source.

Which might be an animal encyclopedia published in the mid-1900s that claimed something about the weight of "500,000 stout men," but isn't.

To wit: According to an article published in New Scientist on August 9, 1979, one aphid, over the course of its life, weighs about 0.2 milligrams. That's about 1/20th of a house fly. Or 1/250th of the amount of acetaminophen in an Extra Strength Tylenol. Which you will need if you find hordes of aphids on your nasturtiums.

The author went on to state that an aphid-infested British wheat field with 500 shoots of wheat in it could harbor as many as a billion aphids, meaning that the larger area he was examining could contain upwards of 800 million million aphids, or 200,000 times the human population on Earth at that time--or about 200,000 tons of aphids.

No matter how you measure it, that's a whole lotta aphids.

And that is quite enough math for my brain in one day.

(To use a phrase popular in today's press, which I hate--the phrase, that is, not the press, because it's overused--"Full Disclosure": I did run across one writer who is rather fond of these dreadful pests, namely Anna Botsford Comstock, who wrote a well-respected nature handbook in 1911. She states, "I know of no more diverting occupation than watching a colony of aphids through a lens. [ed. note: an early version of Youtube, clearly.] These insects are the most helpless and amiable little ninnies in the whole insect world...their eyes, so large and wide apart, seem so innocent and wondering....they are, in fact, merely little animated drops of sap on legs." Then she goes on to describe how to kill them using a nicotine solution.)


  1. Brilliant post! If we didn't have aphids, would we have ladybirds?

  2. We would have very crabby, hungry ladybirds.

  3. No particular desire to be pedantic, but the article you quote actually states that the weight of an aphid is 0.2mg, not 0 to 2. The font on the article makes it rather confusing :s

    1. Not pedantic at all! Much appreciated! Will fix pronto. I shoulda caught that, as it makes no sense to say something weighs 0 mg, anyway :)