Somebody asked me today: 'StormBringer: are there any grubs that we cannot eat?' Now, I'm not a bug doctor, but I have never heard of any grubs we are advised not to eat, although I do recommend to cook your grubs first. Below are some general guidelines for when it comes to eating bugs . . . S.L.
Insects (bugs & grubs) are the most abundant life-form on earth, readily available as a food source in a survival situation. Insects are easily caught and provide 65 to 80 percent protein compared to 20 percent for beef.
Avoid all adult insects that sting or bite, hairy or brightly colored insects, and caterpillars and insects that have a pungent odor. Although certain types of tarantula can be cooked and eaten, advice is to generally avoid spiders and of course common disease carriers such as ticks, flies, and mosquitoes.
Insect larvae are also edible. Insects such as beetles and grasshoppers that have a hard outer shell will have parasites. Cook them before eating. Remove any wings and barbed legs also. You can eat most insects raw. The taste varies from one species to another. Wood grubs are bland, while some species of ants store honey in their bodies, giving them a sweet taste. You can grind a collection of insects into a paste, mix them with edible vegetation, and cook them to improve their taste
Rotting logs lying on the ground are excellent places to look for a variety of insects including ants, termites, beetles, and grubs, which are beetle larvae. Do not overlook insect nests on or in the ground. Grassy areas, such as fields, are good areas to search because the insects are easily seen. Stones, boards, or other materials lying on the ground provide the insects with good nesting sites.
Most species of ants are edible. Because ants secrete an acid when threatened, this gives them a vinegar-like flavor. Ants can be roasted with salt. Queen ants have large, fatty abdomens, therefore provide more nutrition than regular ants.
To harvest ants, one can put a stick on an anthill, wait for it to get covered with ants, then shake it off into a container. Roasting them right away will kill them quickly and prevent them from secreting much of the acid which gives that vinegar-like flavor. Ant larvae are found in clumps under rocks, or on top of anthills when they are being moved or kept warm. They have no sour flavor.
Slugs, like their cousin the snail, are edible and highly nutritious. Slugs are an abundant food source, especially in warm, wet environments. However, slugs (and snails) are host to a potentially dangerous parasite: rat lungworm. They contract this parasite by eating the feces of infected rodents. If a human eats raw snail or slug, these parasites will not live in the body, but can produce a toxic reaction called eosinophilic meningitis. Meningitis is an inflammation of the meninges, a sheath surrounding the brain, and can cause severe brain damage. To avoid this, cook all snails and slugs before you eat them.
Slugs sometimes eat things we can’t — toxic plants and fungi, poo, etc., so gut them by first killing the slug by chopping its head off, then simply squeeze out the entrails. The slug will shrink considerably, and you will get slime on your hands. Cook them chopped up in a stew, or roasted over the fire or chopped, marinated and sautéed, if you have the ability to do so!
Snails are abundant in spring and can often be found in good numbers, making them a good food source. The usual method of preparation is to steam them five to ten minutes, remove from the shell and sauté. They are quite tasty, though if you leave the guts in and they have been eating bark (one of their favorite foods), they will have some astringent flavor. All of the above cautions regarding eating slugs apply to snails. Snails, like slugs, may consume vegetation or fungi toxic to humans. To ensure snails are safe to eat, steam them, remove the shell, then slit the belly remove the cooked entrails.
Inhabitants of open meadows, grassland, fields and some forests, crickets are a delicacy in many traditional societies. They should be fried or roasted before eating. Crickets are excellent pan-fried or oven toasted, with a bit of oil and salt if you like. The legs should be removed before eating as they can catch in the throat and are irritating. Crickets can also be dried and stored for future use.
A simple trap can be made using a Mason jar and some bait. Dig a small hole in the ground of a cricket-inhabited area, put the jar into this hole and move the soil back into place around it or simply put the jar on its side on the ground. A piece of bait is then placed in the jar (a slice of apple, oats, bread, carrot, lettuce, or a banana). In the morning there should be some crickets enjoying themselves in there. Put the lid on the jar, with holes poked in if you want to keep them alive. As a variation, put water in the jar along with the bait and the crickets will drown. Often people use a solution of molasses and water or stale beer for this; other sweeteners or foods mixed with water may also work.
Grasshoppers inhabit similar terrain as crickets and are similarly prepared and esteemed. They can be harvested by hand in the early morning before they are fully awake, using the same type of traps as described above for crickets, or using more ambitious methods.
A method of harvesting grasshoppers - if you have enough people - is holding hands to form a human wall, and walk across a field of tall grass, herding grasshoppers into a tarp on the other end of the field.
Earthworms are highly nutritious. Worms often come out during heavy rains when the soil becomes so saturated with water they need to get out or drown. A method of trapping them is to dig holes (about six inches diameter, >12” deep), in clay soil. After a heavy rain, the bodies of countless drowned worms will be present in the holes.
Worms’ bodies are filled with dirt, which makes worms sandy and unpleasant to eat. This dirt can be removed by purging (soaking them in water for 3–24 hours) or taking a worm in one hand and squeezing the dirt out of it with your free hand’s fingers. After purging, their flavor can be a little bitter. Drying them mellows this flavor, and reduces their sliminess. Frying worms until crispy also makes them more palatable.
Maggots are a traditional superfood. They are also probably the most revolting insect one could imagine. Maggots are extremely fatty and a rich source of essential amino acids, making them nutritionally far more valuable than lean meat.
Aphids are another edible insect. Depending on what foliage they are feeding on, they can range from slightly bitter to sweet. Upon finding an infested plant or patch of plants, simply collect the aphids and eat them fresh or incorporate them into a meal as a nutritious supplement.
Termites are also cuisine in many traditional societies. They can be harvested individually or in small groups and then toasted in a hot pan. They have a high oil content relative to the size of their body and are quite tasty, with a slightly nutty flavor. Winged termites (alates) are larger and fattier. Alates are harvested using a lamp with netting around it. They are attracted to the light and will collect on the netting. The wings are shed easily by winnowing after they have been toasted. A candle next to a mirror at dusk at the right time of year can yield good results.
FM 3-05.70 US Army Survival Manual (formerly FM 21-76)
AFR 64-4 Vol I USAF Search & Rescue Survival Training
SAS Survival Handbook by John Wiseman