Insects are especially common in canned and other types of processed food, and even in certain beverages, like apple cider for instance. They process the fallen and or rotten apples including the worms and insects who have found the apples on the ground.

It is virtually impossible that you have not ingested insects in one form or another during your lifetime. And it probably did not harm you, but instead did you some good by providing extra carbohydrates and protein in your meal! Read more here: http://vm.cfsan.fda.gov/%7Edms/dalbook.html

Insects are commonly found in the following foods:
Apple butter - 5 insects per 100g 

Berries - 4 larvae per 500g OR 10 whole insects per 500g 

Ground paprika - 75 insect fragments per 25g 

Chocolate - 80 microscopic insect fragments per 100g 

Canned sweet corn - 2.3mm-length larvae, cast skins or fragments 

Cornmeal - 1 insect per 50g 

Canned mushrooms - 20 maggots per 100g 

Peanut butter - 60 fragments per 100g (136 per lb) 

Tomato paste, pizza, and other sauces - 30 eggs per 100g OR 2 maggots per 100g 

Wheat flour - 75 insect fragments per 50g

Take the FDA quiz courtesy of brunching.com at this link:
http://www.brunching.com/insectparts.html

Bugs in Your Food By Tara Parker Pope
January 5, 2009, 2:42 PM
http://well.blogs.nytimes.com/2009/01/05/bugs-in-your-food/

How Many Insect Parts and Rodent Hairs are Allowed in Your Food?
 More Than You Think ... and Maybe Than You Want to Know!
http://www.sixwise.com/newsletters/05/06/29/how_many_insect_parts_and_rodent_hairs_are_allowed_in_your_food.htm
Vegan Bits: http://veganbits.com/watch-out-for-bugs-in-your-food/
Title 21, Code of Federal Regulations, Part 110.110 allows the Food and Drug Administration (FDA) to establish maximum levels of natural or unavoidable defects in foods for human use that present no health hazard. These "Food Defect Action Levels" are set on this premise--that they pose no inherent hazard to health.
Poor manufacturing practices may result in enforcement action without regard to the action level. Likewise, the mixing of blending of food with a defect at or above the current defect action level with another lot of the same or another food is not permitted. That practice renders the final food unlawful regardless of the defect level of the finished food.
The FDA set these action levels because it is economically impractical to grow, harvest, or process raw products that are totally free of non-hazardous, naturally occurring, unavoidable defects. Products harmful to consumers are subject to regulatory action whether or not they exceed the action levels.
It is incorrect to assume that because the FDA has an established defect action level for a food commodity, the food manufacturer need only stay just below that level. The defect levels do no represent an average of the defects that occur in any of the products--the averages are actually much lower. The levels represent limits at which FDA will regard the food product "adulterated"; and subject to enforcement action under Section 402(a)(3) of the Food, Drug, and Cosmetics Act.
As technology improves, the FDA may review and change defect action levels on this list. Also, products may be added to the list. The FDA publishes these revisions as Notices in the Federal Register. An update in this regard concerns the Cochineal.
The Cochineal (Dactylopius coccus) is a scale insect in the suborder Sternorrhyncha, from which the crimson-colored dye, carmine, is derived: have a look at the Cochineal: http://en.wikipedia.org/wiki/Cochineal
The FDA Law Blog has a post about the update on the cohineal titled, “FDA Requires Label Declaration of Cochineal Extract and Carmine on All Foods and Cosmetics” By Ricardo Carvajal. Read it here:
http://www.fdalawblog.net/fda_law_blog_hyman_phelps/2009/01/fda-requires-label-declaration-of-cochineal-extract-and-carmine-on-all-foods-and-cosmetics-.html

http://www.fda.gov/OHRMS/DOCKETS/98fr/FDA-1998-D-0032-nfr.pdf

Labeling of Bug-Based Food Colorings Will Help Some Consumers –
Statement of CSPI Executive Director Michael F. Jacobson:
http://www.cspinet.org/new/200901055.html

The debate regarding the Cochineal continues here:
http://www.usnews.com/articles/business/economy/2008/07/11/will-bug-based-food-coloring-catch-on.html

Dave Gracer responds:

“One kind of answer deals with the details – dry-toasted cricket tastes like sunflower seeds; katydid like toasted avocado; palm grub like bacon soup with a chewy, sweet finish. Weaver ant pupae have practically no flavor, while the meat of the giant water bug is, astonishingly, like a salty, fruity, flowery Jolly Rancher. People are usually amazed by it.

The other kind of answer is more theoretical and conceptual: often, insects taste the way that people expect them to. After all, they’re absolutely outside the norm for us and it’s considered freakish to eat them. If insects were delicious then we’d all know it and we’d eat them, since we like delicious food. Whereas if insects are perceived [however incorrectly] as dirty, disgusting, disease-bearing vermin, the chances that they’ll be deemed delicious are pretty low.

Last March David Letterman had an exotic foods expert on the show; the occasion was a banquet at The Explorers Club. There was a long table set up with a slew of weird foods – giant hissing cockroaches were visible, but the short segment did not include that tasting. Letterman tried boiled ostrich egg, eyeballs, rattlesnake, and a bunch of other stuff. Both along the way and at the end he proclaimed them all horrible. Given that these foods were part of a lavish banquet given every year at a prestigious institution, the culinary preparations would not be in doubt. Rather, it’s likelier that Letterman (and, by extension, a lot of people) tried the food expecting it to be awful and this created its own outcome.

This is part of the challenge that I face. In my experience it’s not very often that those people who are willing to try an insect find it delicious. Three possible reasons for that occur to me: 1, that the insects are simply not good-tasting; 2, my cooking skills are not very good; or 3, the afore-mentioned culturally-based predilection toward the rejection of bugs as food.

On the other hand, the most frequent response I get from a taster at one of my events is, “Gee, that’s really not so bad.” This is actually encouraging, and part of me thinks that I should be quite satisfied with that reaction. I’m not. The goal must be to have people amazed at how truly tasty the insects are. I fault my cooking skills, or lack thereof, and I’ve resolved to partner with chefs so that I can bring my abilities to the next level, and do the insect ingredients justice, at last.

Tastes Like Chicken. Really, By Kevin Doyle And Robert Horn, Monday, Mar. 08, 2004
http://www.time.com/time/magazine/article/0,9171,501040315-598581,00.html

The Scorpions Taste Kinda Fishy (a report on the Adventures in the Global Kitchen, the first in a series of programs on global cuisine held at Manhattan's American Museum of Natural History) By Michelle Delio 05.06.04
http://www.wired.com/culture/lifestyle/news/2004/05/63346

Insects Taste Like Chicken? From the USDA Agricultural Research Service (ARS):
http://www.ars.usda.gov/is/kids/weirdscience/story5/insecteaters.htm

Original post blogged on b2evolution.