Some of the photos were replaced if not the best quality.
Indiscriminately dousing plants with harsh insecticides whenever a bug is seen near your plants will also kill many of the these bugs. Neem is good to use. The bug has to ingest the part plant with neem on it to be killed, most beneficials would be spared.
In the grand scheme of things, most insects are beneficial in natural ecosystems. As man grows crops and we have our gardens and ornamentals at home, certain insects compete with us for or feed on these plants and are thus deemed pests. There are several insects that prey on or parasitize these pest insects and these are the ones we will feature in this section. We have chosen the most common ones or featured an insect that closely resembles it.
Predatory insects can be general (feed on many species) or specific (feed on only one or a few species). Many of the most common ones are represented here.
Preying mantis are general predators that catch and feed on moving insects. They are very interesting creatures to watch but probably play a minor role in controlling pest insects.
Big eyed bug
Big eyed bug adults are about 3/16" long and greyish brown. They feed with sucking mouthparts and consume the internal body organs of a variety of insect species. They get their name from large, kidney shaped, reddish brown eyes on the transverse head.
Big eyed bug nymph
Immature big eyed bugs look like the adults except they have no wings and are lighter with irregular spots or patterns on the back.
Damsel bug adult
These general predators are slender greyish or tan insects about 3/8" long. They have sucking mouthparts and feed on many different hosts. This insect is very common in Idaho and the Pacific Northwest. The head is elongated.
Damsel bug nymph
Young damsel bugs look like the adults. Wing pads develop and get larger as the immature approaches the adult stage.
There are many types of assassin bugs in Idaho and the Pacific Northwest. They are general feeders with sucking mouthparts. The head is very narrow and long and the beak is usually fairly pronounced and easy to see. The abdomen extends laterally beyond the wings. They will also readily bite people.
Minute pirate bug
These general predators have a distinct black color with a white triangle on each side of the wings. They are about 1/16" long and also have sucking mouthparts. These are effective predators on thrips and mites.
Minute pirate bug nymph
The immature stage of the minute pirate bug is orange to amber and dark body contents can be seen through the skin.
Two spotted stink bug adult
Several stink bugs are predatory and feed on insects with their sucking mouthparts. A common one in the Pacific Northwest, the two spotted stink bug feeds on larvae of the Colorado potato beetle. Nymphs are colored like adult stink bugs but are shaped like ladybeetle adults without wings.
Green lacewing adult
These adults are around 1/2 to 3/4" long with golden eyes. They are attracted to lights at night. Some green lacewing adults feed on aphid honeydew and plant liquids and others are predacious.
Brown lacewing adult
Smaller than the green lacewing, brown lacewings are also found in Idaho but are not as abundant. These adults will feed on aphids.
Eggs of some lacewings are laid on threadlike stalks to prevent cannibalism among newly hatched larvae. They are usually laid in clusters and easily found on leaf surfaces. Some species lay single eggs without stalks.
Lacewing larvae pierce the skin of their prey with two large sickle shaped jaws. They use them to inject saliva and suck out liquified host body contents. Mature larvae are about 1/3" long. Aphids are the preferred food for lacewings. They will eat several hundred during their development.
Most ladybeetle eggs are in small clusters and can be found on the undersides of leaves. They are usually orange and stand upright from the leaf surface.
Convergent ladybeetle larva
Larvae of many lady beetles are alligator shaped, black and orange, and have chewing mouthparts. Aphids are the preferred food but they will consume other insects.
Scymnus ladybeetle larva
Not all ladybeetle larvae look like the common ones. Many are smaller, have coatings, etc. like this Scymnus larva. These ladybeetles often feed on mites, thrips, and prey other than aphids.
Once the ladybeetle larvae mature they pupate like all beetles. Ladybeetle pupae generally attach to plant stems, posts, or other suitable place. They are commonly found in crops where large aphid populations once existed.
Lady beetle adults
There are about 80 species of lady beetles in Idaho. The more common ones in Idaho are the two spotted, seven spotted and convergent ladybeetles. The smaller black one is Scymnus and represents many of the not so obvious species.
Collops beetles are general predators with chewing mouthparts. The two spotted collops pictured here is common in Idaho and the Pacific Northwest.
Predacious ground beetle adult
There are many species of these fast moving ground beetles that prey on other insects. They are general predators and vary in size and color. Most are black and the head is narrower than the thorax which is narrower than the wings.
Predacious ground beetle larva
No large picture
Immature ground beetles are generally black or reddish brown. They are characterized by having the chewing mouthparts sticking out in front of the head. Many have two flexible short tails on the posterior end.
There are many species of mites that prey on pest spider mites. The beneficial mites are usually clear colored (red, yellow, etc.) and have large piercing mouthparts. Many can be purchased for release into field and home situations.
Syrphid fly adult
These common flies that hover over flowers are beneficial for pollination and the larvae feed on aphids. Many of these flies mimic wasps or bees.
Syrphid fly larva
Syrphid larvae are lumpy, greenish or tan maggots. They feed on aphids and can be found in trees and in crops.