Insects are the most numerous type of animal on the planet. With tens of thousands of different species and billions of individuals alive at any one time, they are among the most important creatures as well, providing a food for many other animals, and helping to pollinate plants. Insects are, therefore, important to a permaculture plot as well.
Some insects are, however, more beneficial to your garden than others, primarily because they help keep populations of “pests” – insects that damage crops – down. Here are some of the little critters that will help keep your permaculture plot in balance.
While the lacewing gets its name from the delicate green tracery of veins on the wings of the adult, it is the larvae of the species that is of most benefit in terms of pest control. Sometimes called “aphid lions” for their voracious appetite for said pests, the larvae also prey upon small caterpillars, mealy bugs and insect eggs. As soon as the larvae hatch they search for food and can eat as many as 40 aphids per day, often, in rather macabre fashion, placing the desiccated husks of their victims on their backs as camouflage. . They have large jaws with which they grasp their prey, immobilizing them so they can suck out their juices. Attracting adult lacewings obviously increases the likelihood of larvae, and they feed on pollen, nectar and honeydew.
Not only are ladybugs one of the most aesthetically pleasing of insects, they are also one of the most beneficial in controlling pests on the permaculture site. Both the adults and the larvae feed on plant-eating insects, particularly aphids but also mites and mealy bugs. Many ladybugs secrete a foul-tasting substance from their bodies to ward off predators, so once in your garden, they are likely to maintain a population if there is sufficient food.
There are approximately 2500 different species of ground beetle, and all of the most common varieties eat a wide range of smaller insects, including caterpillars, potato beetles, cutworms, snails, slugs and vine borers. Predominantly nocturnal, ground beetles prefer to lie low under rocks and plant material during the daylight hours, so make sure you have ground cover crops if you want to attract them. A few species of ground beetle are omnivorous and can consume weed seeds, offering another service to the permaculture gardener.
Adult Braconid wasps only eat pollen and nectar, but they certainly ensure that their young have plenty of prey to feed on as soon as they hatch – by injecting their eggs into other insects. The female will lay an egg in a moth or beetle larvae, leaf miner, caterpillar, fly or an aphid, and when the wasp larvae hatches it eats its way out. Fortunately, the wasps’ fearsome reputation is reserved for other insects; it doesn’t sting so humans have no reason to fear them.
Trichogramma Mini Wasps
Similar to the Braconid wasp, these tiny creatures lay their eggs not inside other insects, but in their eggs. The young mini wasps develop inside, preventing the original insect’s young from developing. They tend to favour the eggs of moths and butterflies, but will also lay in those of some species of worm.
Like their human namesakes, assassin bugs stalk their prey before delivering a killer blow – piercing their victim with an elongated mandible. Both adults and larvae feed on aphids, caterpillars, spider mites and all manner of insect eggs. Be careful if handling assassin bugs as they can bite you as well!
Minute Pirate Bugs
Small they may be (around two millimeters in length), but minute pirate bugs will attack insect prey many times their own size. But while they will take the occasional caterpillar, the majority of their diet is made up of mites, thrips and aphids. While their entire life cycle lasts little more than a month, eggs develop rapidly so, given the right conditions, populations can cycle through several generations during spring and summer. Minute pirate bugs are known to be good pest control additions to greenhouses.
Tachinid flies resemble the common housefly, but are distinguished by having a hairy abdomen. The adults are pollen feeders, but the larvae feed upon grasshoppers, beetles, bugs, caterpillars and earwigs. All species of Tachinid flies are parasitical, meaning their eggs develop either inside or on a host that the larvae predates when it hatches. Different species employ various methods of getting their eggs a host, from injecting it inside, placing it on the back, or sticking eggs to foliage that the prey animal will eat.
An all-round predator, these beetles, which average around half and inch in length when fully grown, can both scuttle along the ground and fly. They are usually easy to spot, with yellow and black or red and black markings on their wings. Adults and larvae feed on soft-bodied pest insects like caterpillars and aphids, while the adults will also feed on pollen and nectar.
Aphids form the largest part of hover fly larvae’s diet, although they will prey on other soft-bodied insects when they get the chance. The adults tend to lay their eggs among aphid colonies so the emerging larvae have food immediately. The adults, which look a lot like yellow jackets, are solely pollen eaters.
Spined Soldier Bugs
Preying on caterpillars, fly larvae, cabbageworms, potato beetles and grubs, spined soldier bugs are a type of stink bug, but are distinguished by their spined “shoulders” which gives their carapace a shield-like appearance. They range in color from brown to bright red.
Preying mantids are arguably the oddest-looking insects you might find on your permaculture plot, at least if you can spot them, they are. Masters of camouflage, preying mantids use their body shape and coloring to blend into plants, from where they attack any other passing insect. This does mean that they will take other beneficial insects, but with healthy populations, their benefits outweigh the loss of a few ladybugs.