Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar

Size Matters

I know that this has been discussed several times before and I even started a forum topic about it once before but it still "bugs" me.

Why can't contributors (especially veteran contributors) fill in the "Size" field on the submission form?
I know :
1). The size a lot of people give is an estimate.
2). People's idea of what size something is varies and two people can look at the very same
critter and give two different sizes for it.
3). Most people's estimates aren't correct.
4). It takes a little more time and effort.
5). Some people don't want to use metrics or don't know how.

And the reasons and excuses can go on and on so I'd rather not discuss reasoning. Instead I want to discuss :
1). Is the size of a critter important to BugGuide?
2). If size is important then why aren't those not giving sizes instructed that they should be?
3). Why isn't the size field made to be mandatory?
4). If size is not important to BugGuide then why isn't it and why have a field for it?

For me personally, I like to know what size critters are because it helps my understanding and also helps for me to know if I'm looking in the right genus for a particular critter. If I have a critter that is 1/4" long and believe it to be "X" critter but the genus or species I'm looking in may be an average size of 1". Obviously I'm looking in the wrong spot. But, if nobody has filled in the size on the submission form then how would I know what the average size should be? ....I wouldn't.
Another point is there have been several discussions lately about BugGuide being a "guide". If that's true then why wouldn't we want as much information as possible supplied with each image, especially the size?

Is important, but most estimates poor
Size is very important, and I try to give size information when I have it. When not, I usually give an estimate and label it as such. For example, I just added size information on Eros humeralis, but it is slow going--I finally found it in one reference, and I had my own measurement to verify it.

My observation is that when new BugGuide contributors estimate sizes, they are can be wildly inaccurate--always on the high side, but people are often very certain of these estimates. We have a lot of beetles that are "about two inches" (50 mm), when, in fact, very few beetles are that large. Our brains focus on a small critter and we see it as much larger than it is--that is human nature.

I'd also like to say that sizes should be quoted in metric units--the English system is just not useful for insects. The coarse nature of the English system is part of the problem with estimates. "About 1/2 inch" in popular usage really covers a wide range in terms of insect size, and is not that useful.
The metric system has been the standard in entomological works, even in the United States, going back into the 19th century.

 
I guess I am an offender . . .
When I first joined Bugguide I was mostly posting previously taken shots, where I had not even attempted to estimate size at the time. I now try to make note of sizes but find, mainly from comments from those knowledgeable enough to provide ID, that my size estimates are often very wrong. I am left questioning if I am better off providing unreliable information or better off providing no information in the size field.

The challenges for me are:
My eye is glued to a viewfinder and everything I am seeing is magnifie, but unless I have twisted out to 1:1 ratio I don't know how much it is magnified.

Even when observing the insect with the naked eye, there is no scale and I can't seem to estimate objects that small accurately. I could identify that one insect is twice as large as another nearby insect very easily but I would be much less accurate in stating if they were 5mm and 10mm, 7mm and 14mm, or 10mm and 20mm.

I do want to be as helpful as possible and, as I photograph a lot of bees, I sometimes use the "honey bee scale" in my descriptions: "about the same size as a honeybee," or "much smaller than a honeybee" etc. I don't know if that is helpful or not.

I have also wondered if "Size" means just the body or would I include legs and/or antenna in my size estimate?

Tim

 
Nice future upgrade
if everyone used metric, it might be possible someday to incorporate some sort of search or Key; I've got a blue beetle with filliform antenna that is 5mm long - what could it be? The other possibility is to add (at least at genus rank) a whole series of boxes for editors to check - size, color, range, antenna type, legs, etc. - LOT OF WORK!

 
....
No, I wasn't saying we shouldn't use metrics. I was just saying some of the reasons I've seen are that "I don't know how to use the metric system", and things like that.

I like to put the size. I th
I like to put the size. I think it is very useful, yet many times I don't have a size. Maybe I only got a snap or two and have no idea of the size. I am really bad about that.

On another note I have read from someone before on how to size your bugs by counting pixels on the picture, just don't remember how it worked....

 
I don't know about counting pixels...
but a simple thing you can do is figure out what your field of view is when you're as close as you can get, by taking a picture of a ruler. With my 105mm lens, it's 2 cm, and with my 18-55mm lens it's 7 cm (when set to 55mm). If you know you were as close as you could get to your subject while still being in focus, you can then shrink the image to actual size on your screen and measure the bug with a ruler. If you weren't as close as possible you can still give this measurement as a minimum size.

Most of the images that I submit without a size indicated were taken five years ago with a different camera, and I see no point in estimating when I have absolutely no clue. Most of these are bound for Frass anyway.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.