How much are 16 caterpillars worth?

Today's garden yield included 2 cherry tomatoes, over 6 pounds of Manderin oranges and 16 juicy caterpillars.  Since early November when I did a big seed catalog order, I've been keeping track of my garden expenses and yields.  My little spreadsheet includes expenses of seeds, plants, pots and stakes totally $73.49.  I didn't include wages for our work or expenses of watering because they were too hard to quantify and, hey, its a labor of love.  My yields record all the garden produce I've harvested since November 1: chard, lettuce, eggplants, tomatoes, herbs, lemons, oranges, lima beans, black-eyed peas, pomegranates, radishes, potatoes, and butternut squash.  Assigning values to each produce item, trying to be comparable to organic produce at the store, my yield so far is about $156.  But today's yield included 16 little green caterpillars eating my turnip greens.  How much are they worth?  How will I fit them into the equation?

I plucked them off.  They are now residing in a jar with greens from turnips and from a nearby radish, which wasn't infested with the caterpillars.  I'm setting it up as a preschool science experiment.  Do you think the caterpillars will selectively eat the turnip greens in the jar?  Or had they just not noticed my lovely radishes?  Oh!  Gotta add the radish and baby turnip to the yield totals!

Ok, my science mind is starved by motherhood.  I got out some old equations to work on the caterpillar density.  I know that 16 caterpillars might not sound that remarkable to you, but they were found in my little container garden.  One pot of lonely turnips, the pot being about 12 inches in diameter.  Feel free to check my math...  That is a radius of 6 inches.  The surface area of the pot is pi*r*r = 113.1 square inches.  That's 0.15 caterpillars per square inch, or 20.4 caterpillars per square foot.  Gosh, if I had an acre of turnips, they'd have 887,397 caterpillars on them!  That feels like a caterpillar plague of Biblical proportions in my little pot!